UL S8 Date Due
Y 10 1998

PRINTED |IN U.S. A,

 
 
U.S, DEPARTMENT OF AGRICULTURE.

BUREAU OF ANIMAL INDUSTRY.

 

 

dee)

ANIMAL PARASITES OF SHEEP.

BY

COOPER CURTICE, D. V.S., M. D.

+ PUBLISHED BY AUTHORITY OF THE SECRETARY OF AGRICULTURE.

WASHINGTON:
GOVERNMENT PRINTING OFFICE.
1890.
 
TABLE OF CONTENTS.

Letter of transmittal, J. iccciewe genes cascee demons ciiap aecved segues secaecese
General TeMmarks 22 geist ae aay weeerje mcs Sees a cic sthwee cu wniee Siaon
Parasites of the nose:
Grub in the head, @strus ovis, Linn............-- tebseGreeemecosicnes
Parasites of the skin: Phthiriasis, Acariasis.
The sheep tick, Melophagus ovinus, Linn............--- ri ste a measur aeto ata
The sheep louse, Trichodectes sphwrocephalus, Nitzsch.........-...-----
The goat louse, Trichodectes limbatus, Gervais, and Trichodectes climax,
Nitgg@h cciccwconais eweenyatewecenence ctachsteswegumeosedmen deeerecce
Scab insects: Acariasis, iteh, scab.
Head scab, Sarcoptes scabiei, de Geer, var. ovis....-.....--2.----------
Common scab, Psoroptes communis, First, var. ovis.......------..2----
Foot scab, Chorioptes communis, Verheyen, var. ovis...........--..25+-
Parasites of diverse organs:
The pentastoma, Linguatula tenioides, Rud... .-.--...-.0-20 .22-e2 eee
Immature tape-worms:
Bladder worms, Tenia marginata, Batsch .....-..-..0--2. 22-0 ween ee
Gid or staggers, Tenia ceenurus, Ktich.--. 2.20. ---- cee e ee eee eee eee ee
Hydatids, Tenia echinococcus, V.Sicb....-. 2-2-2 eee cece ne eee eee
The mutton measle, Twnia tenella, Cobbold...... 2... .2-222 eeeeee eens
Parasites of the alimentary canal and appendages:
Adult tape-worms:
The fringed tape-worm, Tenia fimbriata, Diesing...-.. be pieighls, she sees
The broad tape-worm, Tenia expansa, Rud ...... 422-02 ee 20s cee e ee ee
Liver-flukes:
The large liver-fluke, Distoma hepaticum, Linn...--..----.-..22. 22-026
The small liver-fluke, Distoma lanceolatum, Mebhlis
The stomach worms:
Amphistoma conicum, Zeder .... 2-2-0 02-220 nee n vee ee cee eee eee eee
Strongylus contortus, Rud ...-.-..- +22 -- 22 ee oe eee eee tee ee eee eee eens
Intestinal round worms:
Introductory remarks, ........-.-- ---2 ae nee eee eee eee ween ewes
Strongylus filicollis, Rud .-.--.-.-. 2-2 2-022 eee eee Doce ictusaines taemee’
Strongylus ventricosus, Rud ..-...---.-- cee -2e cence e ee eee cee eee cee
Ascaris lumbricoides, Linn...... ---- 2+ 2-222 ene eee cee ee ce eee eee wees
Dochmius cernuus, Creplin -...-. 2.2205 cece cece ee cee cee cena sees
Sclerostoma hypostomum, Diesing ..-...---.--.-----+---ee eee ween ee
. The nodular disease of the intestine, Hsophagostoma Columbianum, n. sp
Trichocephalus affinis, RuG . 2... 2206.22 22 eee ee eee ence were e teens
Parasites of the lungs: ,
Introductory remarks. i005 s0ccerewcess wenn secews seuslqsietieee cee sees
The hair lung-worm, Strongylus ovis-pulmonalis, Diesing......--.-----
The thread lung-worm, Strongylus filaria, Rud ..---..--.---+---.---+

 

69

72
83
86
87

89
113

127
137

138
141

145
146
149
151
155
161
165
181
PLATE , ods
Il.

Til.

IV.

VI.
VIII.

IX.
x.
XI.

XII.
XIII.
XIV.
XV.
XVI.
XVII.

XVIIL.
XIx,
x,
xx,
XXII.
XIU.

XXIV.

XXV.
XXVI.

XXVII.

XXVIII.
XXIX.
XXX,

XXXI.

XXXII.

XXXIII.

XXXIV.
XXXYV.

XXXVI.

INDEX OF ILLUSTRATIONS.

Page.
Gstrus ovis, Linnmus ..-.-..- MG SRSC eee MER ceteemse Pauses 34
Géstrus ovis, in sinuses of the head ...-...---..---- 02. ---- 36
Gstrus ovis, in nasal cavity and sinuses of the head .....-.. 38
Melophagus ovinus, Linneeus........ ole Vbeee ECan eee seineee 44
Trichodectes spharocephalus, Nitzsch...---...---- 220. sees cece 48
Trichodectes limbatus, Gervais, et T. climax, Nitzsch......-... 52
Psoroptes communis, Fiirst., var. ovis. Adult ...........---- 66
Psoroptes communis, var. ovis. Young ..-..-..--- aeueesipesicis 68
Tania marginata, Batsch ...-...----+ +20. eee e ene ee eee e eee 80
Tania marginata, in the liver ...-....---..---2. 2-52-22 eee 82
Tania tenella, Cobbold, T. cenurus, Kuchenmeister, et T. ech-
MOcdCEUS VY. SiCDON die wccicesiccccc ccceeta comesnaeccleges nese 88
Tenia fimbriata, Diesing -.---...... 200-220-222 eeeee svsiocee 110
Tenia fimbriata, original figures of Diesing .--.-..-...------ 112
Tenia expansa, Rudolphi. Adult...--..----.-----.--2------ 124
Tenia expansa, young stages..-.....---.----------- oqatestes 126
Distoma hepaticum, Linnweus....---- 0-200 econ ee eee eee eee eee 136
Linguatula teniodes, Rudolphi, Amphistoma conicum, Zeder,
et Distoma lanceolatum, Mehlis ...--.------.----.--------- 140
Strongylus contortus, Rudolphi..-.-..----.------ -.ese. eee eee 144
Strongylus filicollis, Rudolphi ...--..-..---.-----. 2-0 eeeeee 148
Strongylus ventricosus, Rudolphi......---.-..---++--+.+----- 150
Ascaris lumbricoides, Linneus -------...- Gaine waiters gape wise eels 154
Dochmius cernuus, Creplin..---..----- 2-202 cee e cece eee wees 160
Sclerostoma hypostomum, Dujardin.....-.----. 02-220 e-ee ---- 164
Csophagostoma Columbianum, Curtice. Adult ....-...--.--- 174
Gsophagostoma Columbianum, young stages..-.--.-.-------- 176
Csophagostoma Columbianum, in the intestinal coats ....--.- 178
Csophagostoma Columbianum, in the intestinal coats...-.... 180
Trichocephalus affinis, Rudolphi........-----.--++---+-----+- 184
Strongylus ovis-pulmonalis, Diesing ....-...--+.+----+-++--+- 192
Strongylus ovis-pulmonalis, in the lungs......----.----+---+- 194
Strongylus ovis-pulmonalis, in the lungs..... -....-----+----- 196
Strongylus ovis-pulmonalis, in the lungs....-...---.---- aceon: | 198:
Strongylus ovis pulmonalis, in the lungs ..---.-----.---++---- 200
Strongylus filaria, Rudolphi......-.-.---------------e0----- 210
Strongylus filaria, in the lungs ..---..----.-----------+--0-- 212
Strongylus filaria, in the lungs .......-.-.0---22---eeee eee 214
LETTER OF TRANSMITTAL.

WASHINGTON, D. C., April 21, 1890.

Sir: I have the honor to submit herewith a report upon the para-
sites of sheep, which has been prepared with much care and will prove
of permanent value to ali owners of this class of our domesticated ani-
mals.- The information heretofore attainable on this subject in the
United States has been fragmentary and in many caves unreliable,
although the parasitic diseases of sheep are among the most frequent
and serious maladies by which this species of animals are affected.

It has been the aim in the preparation of this volume to make the
descriptions and the illustrations so plain that any one will be able to
identify the parasites which he may find in his flock, and yet the sub-
ject is in some of its aspects so technical that it could not bé presented
entirely in popular language. The technical descriptions which it is
deemed necessary to insert have, however, been placed in small type,
and those not interested in the characters by which the species are
identified can omit such paragraphs. The symptoms and appearances
presented by diseased animals and the treatment of the diseases have
beenggiven at considerable length, and these will be read with interest
by all who desire information on this subject. The illustrations are a
prominent feature of the work, having been drawn and lithographed
with the greatest care, and every attention given to make them accu-
rate in their most minute details. Nearly all of these are original and
were drawn from nature. i

The nodular disease of the intestines, together with its cause, is de-
scribed for the first time in these pages. This disease is common and
wide-spread, but its cause and nature were mysterious until they were
discovered through the investigations of this Bureau. We have here
once again a demonstration of the value of systematic, scientific in-
vestigation of the diseases of animals, for the results obtained by the
study of this malady are among the most interesting contributions of
modern research. The facts obtained in the investigations of the fringed

‘tape-worm and the hair lung-worm are also of more than ordinary in-
terest.

‘The subject of parasites and parasitic diseases is one of great impor-
tance, and must become more prominent as the number of domesti-
cated animals in the country increases and the pastures become more

7
8

limited in comparison with the flocks which graze upon them. Under
such conditions parasites multiply more rapidly, and their ravages be-
come more alarming. For this reason the time has come when we must
pay more attention to these organisms and study more assiduously the
means of controlling them, if we would preserve that healthfulness and
vigor for which the animals of this country have heretofore been noted.
It is hoped that the systematic treatment of the subject presented in
the accompanying volume may assist in accomplishing this object.
Very respectfully,
D. E. SALMON,
Chief of the Bureau of Animal Industry.
Hon. J. M. Rusk,
Secretary of Agriculture.
ANIMAL PARASITES OF SITEEP,

GENERAL REMARKS.

In 1782, Goze, a distinguished German naturalist, wrote: “Among.
all mammals except the horse, the sheep appears to be most harassed
by worms.” He thus called attention at that early period to the great
abundance of ovine parasites, au abundance which have transmitted
their posterity in comparatively undiminished numbers.

The presentation of all the facts now known concerning these para-
sites, their structure, their life histories, the injuries they cause, and
the methods of prevention and treatment, together with such new ma-
terial as may have been learned concerning them, needs no apology to
the sheep owner, for he is alive to the fact that the majority of his losses
is due to these parasites. The sheep industry of the United States
embraces the product of 42,599,079 sheep, valued at $90,640,369.* De-
pendent on these sheep and their products are an army of menand their
families, from the flock-master and his help to the consumers of the flesh
and the manufacturers of the fleece. Add to this the value of the plant,
which is dependent on the sheep industry in all of its ramifications, and
there results an accumulation of many millions of dollars, a value which,

from a business stand-point alone, should cause the Government to

foster and to protect it from every source of injury.

As the whole growth of the industry is dependent on the health and
vigor of the sheep, it follows that whatever tends to produce a better
condition or ward off threatening disease from them is for the benefit
of all interested in and dependent upon the success of the industry.
The parasitic diseases —-those produced by the animal parasites of
sheep—are, if we may judge from observation and the letters of inquiry
directed to this Bureau, the chief source of losses, and ifin any way this
bulletin may result in promoting a better knowledge of these too little
known pests, and in teaching facts which will lead to better care and
treatment of the flocks as regards hygienic prevention of diseases, the
cost and labor laid out upon the work in its various details will be well
expended.

Particular attention has been devoted to illustrating each species of
parasite, and, so far as possible, the lesions of the disease produced by

 

* United States Department of Agriculture, report on numbers and values of farm-

animals, J snes February, 1889, pp. 5 and 6, 5
10

it. In the illustrations of the species certain features which present
specific differences have been constantly drawn. Peculiar features of
anatomy and development have also been illustrated. The entire de-
velopment of any species from the unimpregnated ovum to the adult
form is not illustrated, but one species may show the developing ova,
another the embryo, and still another small and adult forms, and thus
the entire development of many of the species can be well understood.
Especial attention has been devoted to representing certain organs of
economic importance, i. ¢., those organs which are immediately con-
cerned in injuring the tissues of the sheep. The majority of the draw-
ings were made from nature by Mr. W.S. D. Haines, and the others by
Dr. George Marx, both artists connected with this Department. The
excellence of their work shows for itself. Where material for original
illustration has been unavailable, figures chosen from the leading
text-books on the subject under consideration have been copied, and
due recognition of the source acknowledged in the description at-
tached. For the accuracy of these drawings the author alone is respon-
sible. He believes that all the anatomical details are accurate, but such
is the difficulty of seeing the minuter details that some of the latter are
omitted. As their presentation belongs properly to a more specific
investigation than this their absence will scarcely be noticed. It has
been the constant endeavor of both the artists and the author to make
technically perfect drawings, and at the same time present the subject
so clearly to the eye that not only a novice may, by the aid of a small :
magnifying glass, be able to determine the species, but that the scien-
tist may also use the work profitably in subsequent investigations.
- The text devoted to each species is intended to contain a general
description of the parasite, its life history, the way it causes disease,
the disease produced and mode of treatment, both preventive and re-
medial. Many of the specific descriptions are technical. To the be-
ginner, who can identify the species by careful comparison with the
figures, these are unnecessary, but as he advances in their study the
meaning of the technical descriptions will become more apparent and
useful. In a work of this character such technical specific descriptions
are unavoidable. To the scientist they are absolutely necessary.
Wherever possible the complete life-history of the parasite is described
and illustrated; unfortunately, however, the species whose life-histories
are positively known are too few. Although the life-histories of the
majority of the worms seem very evident, still the evidence upon which
they are based is not deemed entirely conclusive by scientists. So skep-
tical are the majority of this guild that rigorous proof alone seems to
satisfy them, and this is particularly the case when the views set forth
in regard to either of the species are at variance with pre-existing
opinions. ‘

Rigorous demonstration of the various stages in the life-history of a
parasite demands that its eggs or embryos shall be fed to an uninfected
11

host (sheep in this case), and the parasite be found in it subsequently,
at a stage of growth corresponding to the time which has elapsed dur-
ing the experiment. The conditions necessary for raising embryos, for
procuring uninfected sheep and for keeping them from outside sources
of infection, are many and difficult to fulfill. Up to the present time,
with few exceptions, infection has been secured in the experiments only
by excluding or regulating certain of the conditions surrounding sheep.
These conditions are such that, although the problems in each case
have not been absolutely proven, there is much probability that the life-
history of most species is well determined. In describing the injury
wrought by the parasite and the resulting disease, technical descrip-
tion has been avoided as much as possible, in order that the work may
be rendered more valuable for farmers and ranchmen, who have but a
limited knowledge of the terms used in medical literature. ‘These de-
scriptions are, on this account, necessarily imperfect from a scientific
point of view, but it is hoped none the less efficient for the purpose:
A careful study of the various diseases will show that the irritations
set up and the lesions resulting therefrom are mainly due to mechan-
ical causes, whatever be the organ attacked. Certain of the dis-
eases, however, seem to be aggravated by nervous or reflex irritation .
induced by the parasite, while others are hastened by a loss of blood or
nutritive material abstracted from the host by the parasites.

The diagnosis of parasitic diseases is always determined by finding the
parasite or its eggs. The quickest and surest determination for inter-
nal parasites is made at a post-mortem examination. For intestinal
parasites many authors recommend the examination of thedung. This
method has not been verified by experience, but appears to be tedious
and difficult, and a method better adapted to experts than layman.

There are certain symptoms from which one may infer that sheep are
infected with parasites. A large part or all of the flock is affected and
the symptoms shown by the different individuals are similar. The ap-
petite is generally good, but individual members present a poor, stunted,
hide-bound, bloodless, big-headed, pot-bellied appearance. Other local
symptoms, ‘depending on the organs affected, are present. The most
positive characteristic is to find that a number of sheep raised together
are affected in the same way. From these general symptoms those de-

_ pending on climatic changes, and irregularity or insufficiency of food
and water, mustof course beexcluded. The sheep owner who discovers
weakness among his lambs should not wait until one of them dies before
he endeavors to make a diagnosis, but should undertake to diagnose the
disease in the earlier stages by sacrificing one or more of the worst
affected, and thus gain time in treating and preventing the extension of
the disease. By waiting for the disease to develop he allows the lambs
to grow poorer and weaker, and when action is finally undertaken it is
upon patients which are, in many cases, already too weak to stand
vigorous treatment, and which can in no way profit by preventive
12

‘measures as they should. The lambs examined can, if the meat is not
too poor and watery, be used on the table without harm to the consumer.
If the animals are at all feverish, as is the case in the later stages of
disease, the carcasses should be thrown away. It isin the beginning
of the disease that treatment, both hygienic and medicinal, is needed
and produces its best results, and therefore an early diagnosis and de-
termination of the malady is fully as essential as in the more virulent
bacterial scourges.

Though the treatment advised in a work of this character should be
jts strongest point, yet it is to be regretted that such is the state of
knowledge of the life-history of these parasites and of the practical re-
sults of medicines used in combating them under the conditions in
which sheep are held on the pastures, that it is felt that this field is yet
to be properly entered and worked up from an experimental stand-point.
The subject appears, as yet, to be in an empirical stage. Although the
best recipes have been compiled and presented, they appear to be old
and hackneyed to one who has been enabled to trace the same recipes
from book to book. Indeed, some of those presented, which contain
inherent virtues, come from countries where sheep-ranching is unheard
of, and seem to be sufficient only in the closely. settled communities
where labor is cheap and where time can be devoted to saving property
even though the value is not great. The medical treatment of large
flocks should be investigated from a broader stand-point than any yet
taken. Our insufficiency of knowledge on these points arises from the
small value of single animals and the hesitation of people to seek the
aid of skilled veterinarians until they find that they are unable to treat
the disease themselves. The great benefit in doctoring animals whose
individual worth is but a few dollars lies in the treatment of numbers
at a time, and in making an early diagnosis of the disease. Those who
have large and valuable flocks should watch their lambs for the earli-
est symptoms, and then if there is a skilled veterinarian available ob-
tain his services. Oftentimes the family doctor can and will give advice
that will materially assist, for his knowledge of other diseases, their
symptoms and lesions, and of the use and effects of medicines; make
him the most available authority in the absence of the veterinarian.

Upon the hygienie treatment, t.¢., upon the care and attention the
flock receives, depends in great measure its health and good condition,
and the prevention of the parasitic diseases. It is out of the province
of this bulletin to discuss the proper housing, food, and drink of sheep,
beyond what is required for the prevention of parasitic maladies. The
chief necessity as regards buildings and yards is that they should be
kept clean. Periodic cleansings of wood-work and floors should be
sufficient. Whitewashing and the liberal use of lye water for cleansing
wood-work are desirable, and in some diseases, such as scab, absolutely
indispensable. In the careof yards an economic management of the
manure is to some of prime importance. It would seem that a mixture
13

of this manure with lime in the compost heap, and a frequent cleansing
of the yard, would be far better, so far as the sheep are concerned, than
to allow it to accumulate. The lime would not only serve to kill the
eggs of parasites in the manure, but would add fertilizing material to
it. Manure so treated would be a better ‘fertilizer, and would also be
less apt to infect sheep when spread upon the fields. The compost
heap should ‘never be where the liquor from it can be washed by the
rains into water which the sheep drink. As the manure from these
yards may prove the source of infection, sheep should never be pastured
on fields recently enriched with it, unless there is absolute certainty
that the previous treatment of the manure has destroyed all the em-
bryos of the parasites. As frequently urged in the text, every means
should be taken to supply sheep with pure water. Although experi-
ments show that sheep have other means of getting parasites than from
the water they drink, yet this is at times a very fertile scource of infec-
tion. The use of drinking-troughs into which water runs or is pumped,
and rapidily running water, seem best suited to meet the requirements.

The grain food should be fed from cleanly swept troughs or floors.
Hay should be put in racks, as feeding from the ground is not only
wasteful but tends to infect with parasites. Salt should be supplied in
boxes placed where sheep can have ready access to it. The mixture
of a small proportion of finely powdered sulphate of iron with the salt
is allowable at times.

Pastures, which are ordinarily uncared for further than to provide
fences tor securely confining the sheep, need careful.supervision. Wet
swails, bogs and swamps should either be fenced out or drained. Past-
ures which are overstocked, and in which a flock of sheep is kept con-
tinuously, are the most fertile sources of infection. Not only do the
sheep become more frequently infected where they are compelled to eat
the grass close to the ground, but the chances of their being compelled
to graze on an infected area are largely increased by keeping them
ranging over the same ground of limited area week after week. Old
sheep stand such treatment much better than young ones. For the lat-
ter, those fields which have not been pastured on by older sheep are
better. The practice of feeding the sheep over fields from which the
crops are removed is a good one, not only for the sheep but for the
fields. These remarks, of course, apply more strictly to fenced farms
and not to unfenced sheep ranges, but even on these certain portions
of the range can be reserved for the lambs. The practice of allowing
lambs, atter they are old enough to wean, to feed after older sheep is
also a source of infection.

The relation of the dog to sheep husbandry is too important to be over-
looked. Were it not that the definition of parasite excludes such ani-
mals as can be considered beasts of prey, the dog would be placed at
the head of the list of parasites as being the most destructive. Though
this be unmistakably apparent to a large majority of sheep-owners,
14

there are many who believe that the dog is man’s most faithful friend
and that he is of great use even on a sheep farm. It is unfortunate for
the dog that the mass of testimony on this subject is against him. It
is not from the stand-point of the dog as a beast of prey, how:2ver, that
this work is written, but it is from the more technical stand-point of the
dog as a carrier of parasites dangerous to sheep and man. In the list of
parasites of sheep there are at least four which are common to the dog
and sheep, viz: Tenia marginata, Batsch; 7. cenurus, Ktich.; T. echi-
nococcus, v. Siebold, and Linguatula teenioides, Rud. The last is rare,
and in justice to the dog should not be used against him, although it
may subsequently afford as damaging evidence as the other species.
By referring to the descriptions of the other three species it will be
found that dogs harbor in their intestines the adults of these species,
and that they scatter the eggs of the parasites broadcast for the infec-
tion of sheep. Thus each dog, harboring one or more, is a constant
menace to the health and lives of the flocks in the neighborhood. Nor
is this all, for man himself can be infected by at least two of these spe-
cies— Tenia echinococcus and T. marginata—in their cystic stage. The
- former of these species produces a disease of slow development, but one
which is nearly always fatal in results. To prevent these diseases the
precautions prescribed in the text must be closely adhered to. A plan
which would remove much of the loss caused by dogs by doing away
with them entirely is scarcely practical in this country, where the ma-
jority of these animals are owned by persons who have no direct inter-
est in sheep. The hunting and the sheep dog are most to be féared,
unless we except some of the fiercer watch-dogs which are kept at
slaughter-houses and fed on waste bits. The day of the usefulness of
hunting dogs is quite past, and their retention by sheep-men at least
should be abandoned. The watch-dogs are nearly always chained and
in places not accessible to sheep.

In the range country the coyotes and prairie wolves still menace the
flocks by killing individuals for food, and by harboring the adults of
Tenia marginata and T. cenurus, ies eggs of which they also scatter.
In most sections, especially where a bounty is offered for their scalps,
the trap is remorsely exterminating them. Laws which would subject
the mongrel curs to the same treatment would result in a great gain to
the farming community and to their respective owners, if they be owned
by any one.

There are reports that the sheep can be infected by parasites from
some of the many wild animals that still haunt the land where they
were formerly so abundant. The examination of these little quadru-
peds to ascertain the parasites they contain has not been as extensive
as it should be for a broad generalization, but so far as it has extended
it is safe to say that sheep are not infected from either rabbits, skunks,
squirrels, woodchucks, gophers, prairie dogs, or foxes. Foxes may
harbor some of the adult Tenia whose cystic stages infest sheep, but
15

unless they can obtain the young forms of the parasites by eating the
viscera of sheep they would be very unlikely to be infected with adults.
It is also reported that rabbits harbor the cystic form of Taenia margin-
ata; but this statement has not been corroborated, as the rabits ex-
amined contained the cystic form of T. serrata. If rabbits should be
proven to harbor the cysts of ZT. marginata then the danger would
arise, not from them, but from hunting-dogs which eat the rabbits and
the cysts they contain, and harbor the adult parasites that alone are
the source of danger. The possibility of infection by parasites from
deer is too small to be considered as an economic question, owing to
the great scarcity of these animals. The antelope (Antilocapra ameri-
cana, Ord.) may be a bearer of many of the same species of parasites as
the sheep, but they also are becoming too few to be considered as a
source of danger. In short, it is futile for the flockmaster to consider
these sources at all while his own flocks are infecting his fields, and his
dogs are constantly assisting them. Could these sources of infection
be controlled, there would be no need for him to regard the wild ani-
mals as his enemies.

In purchasing sheep particular attention should be paid to the gen-
eral appearance and past history of the flock from which the purchase
is made in order to avoid parasitic diseases. Before adding recent pur-
chases to flocks they should all be thoroughly dipped to kill external
parasites. If they are coughing ever so slightly, the cause of the cough
should be investigated to determine the presence or absence of lung
worms. If some are hidebound or weak after allowing for the charac-
ter of the season and the condition of pasturage the possible presence
of intestinal parasites should be next considered. It is not very prob-
able that there are any farms free from all parasites, but there are many
that are free from a considerable portion of the species which are prop-
erly parasitic on sheep. Purchasing here and there in making up a
flock brings all sorts of parasites together, thus infecting afarm to such
a degree that it is difficult to get rid of them.

The medical treatment must, of course, be specially adapted to the dis-
ease. The treatment of external parasites is effective, and well repays
all efforts. The treatment of internal parasites may be divided in gen-
eral into treatment for lung worms, for intestinal worms, and for liver
worms. The last is by far the most unproductive of good results. Par-
asites situated elsewhere in the sheep do not readily yield to medical
treatment.

Scab is the only parasitic disease that has been thought worthy
of legislation. There are others that demand as serious considera-
tion, but their importance has not yet been fully presented to the
public. Little attention has been given to police interference in the
management of these diseases. No doubt such interference might be
profitably pushed further than it is in this country, especially with
regard to scab. Not only should the highways be guarded against the
 

16

movement over them of scabby sheep, but a competent imspector
should be appointed by the State to supervise every sheep dipping, to
compel the dipping of every scabby flock, and to attend to the renova-
tion and disinfection of the sheep-yards and walks. Every band of
scabby sheep is a constant menace to the health of others. In this
country there seems to be no sheep disease produced by animal para-
sites which renders the flesh harmful to man, further than that some
of the flesh may be less nutritious. Until the sale of meat of all kinds
is guarded by more stringent regulations there does not seem to be any
reason for urging police restrictions on the sale of meats of the inferior
quality which some of these diseased lambs undoubtedly furnish.
There are described in this volume twenty-six species of animal para-

sites of sheep, as follows: .

1. Gstrus ovis. 14, Distoma hepaticum.

2. Melophaqus ovinus. 15. Amphistoma conicum.

3. Trichodectes spharocephalus. 15. Distoma lanceolatum.

4, Trichodectes climax. 17. Strongylus contortus.

5. Trichodectes limbatus. : - 18. Strongylus filicollis.

6. Psoroptes communis. 19, Strongylus ventricosus.

7. Linguatula tenioides. 20. Ascaris lumbricoides.

8. Tenia fimbriata. : 21. Dochmius cernuus.

9. Tenia expansa. 22. Sclerostoma hypostomum.
10. Tenia marginata. 23. Gsophagostoma Columbianum.
11. Tenia tenella. 24. Trichocephalus affinis.

“12. Tenia cenurus. _ 25. Strongylus ovis-pulmonalis.
13. Tenia echinococcus. 26. Strongylus filaria.

 

Of the species described three genera—Melophagus, Trichodectes, and
Psoroptes, embracing five species, M. ovinus, T. spherocephalus, T. cli-
max, T. imbatus, and P. communis—are external parasites.

The.species which there is reason to think do not occur in this coun-
try are Tenia tenella and Amphistoma conicum. The former is consid-
ered by continental authorities as a synonym of 7. solium or T. margi-
nata. The writer has not found Linguatula tenioides, Tenia coenurus,
T. echinococeus, Distoma hepaticum, or D. lanceolatum in sheep, nor
learned from authentic sources of any of these occurring here except D.
hepaticum. The other species may eventually be found, but they will
probably be rare. One other species, Ascaris lumbricoides, seems to
be a rare one in sheep. The remaining species are all more or less
abundant. Tenia fimbriata and Gfsophagostoma Columbianum seem to
be exclusively American species. The others are common to all parts
of the world where there are sheep. Von Linstow (Compendium der
Helminthology, 1878), catalogues nineteen species of internal parasites
which infest European sheep. One of these, Monodontus Wedlii, Molin,
is a synonym of Dochmius cernuus Creplin; another, Nematoideum
ovis, Diesing, is a lung-worm insufficiently described. Still another,
Trichosoma papillosum Wedl., is a synonym of Strongylus filicollis, Rud.
The remaining sixteen species are described in this volume. There are

 
17

two lung parasites of sheep in the Old World that have not been found
here, viz: Strongylus rufescens, Leuckart, and S. minutissimus, Megnin.
The former is said to occur in Germany and France, but is so meagerly
described that it probably is not a distinct species, but asynonym of
Strongylus (Pseudalius) ovis-pulmonatlis, Diesing. The latter occurs in
Algeria, is well described and figured, and seems to be a well estab-
lished species. Strongylus ventricosus, also a European species, has
not, to my knowledge, been described as a parasite of sheep heretofore.

A further comparison of the above list with those of parasites of sheep
in other countries is re-assuring, because, first, native sheep have now
nearly all the parasites that they can acquire in this country; second,
that although nearly all the European species have been imported, Dis-
toma hepaticum, L., the liver-fluke, Tania .echinococcus, v. Siebold, and
T. cenurus, Kiich., are either very rare or else do not exist in this coun-
try. These three parasites have been the cause of great loss among
sheep in other parts of the world.

The comparatively long list of parasites furnished will seem to the Eu-
ropean to indicate that sheep in this country are more infected than
those in Europe; but in this connection it should be remembered that
much time has been spent in hunting for several of these species, and
some of them are rare, inconspicaous, and do little damage.

The following is a list of our mest destructive ovine parasites:

Cstrus ovis, L.; Psoroptes communis, Fiirst.; Tenia fimbriata, Diesing;
T. expansa, Rud.; Strongylus contortus, Rud.; Dochmius cernuus, Creplin;
Csophagostoma Columbianum, Curtice; Strongylus ovis-pulmonalis, Dies-
ing; and S. filaria, Rud. There are nine species in all, a list which
compares favorably with that of the ovine parasites of any other coun-
try ; for all but two species, 7. fimbriata and O. Columbianum, are coin-
mon to all countries, and these two are more than offset by the preva-
lence of more destructive parasites in the Old World.

On the whole, the flockmasters of the United States may be congrat-
ulated on the good condition of their flocks and their comparative free-
dom from both external and internal parasites.

PARASITISM.

Definition.—The animal parasites of sheep are those which live in or
upon their living bodies and obtain nourishment from them. The term
“animal parasites” is used in order to distinctly separate this group
from the vegetable parasites which attack the living organs of sheep.
Both animal and vegetable parasites prey upon the flocks and cause
disease, but such are the differences between them, their effects and the
methods of investigating them, that an investigation of either forms a
large field of research.

Parasites as defined above include a large number of animals so dif-

ferent from one another that parasitism is the only common character
PANAR aA nm 2
18

which groups them together. Though this distinctive feature is suffi-
cient for the present purpose, it is a very variable character, for the
degree of parasitism manifested by each of the species varies through
all the scale possible from the transient momentary parasites to the
permanent.

The animal parasites of sheep are all embraced within three great
branches of the animal kingdom: The Protozoa, Vermes, and Arthro-.
poda. None of the first branch, which includes the Coccidia and Bal-
biana gigantea, Raillet, are described in this volume. Examples of the
second, which includes all the worms, and of the last, which includes
the insects, mites, and linguatula, are abundant.

The worms live, as a rule, in the open cavities of the body—in air
spaces of the lungs, the ducts of the liver, and the lumen of the intes-
tine. The exceptions to this rule arise from those immature forms
which penetrate into the substance aud closed cavities of the bodies,
e. g., the bladder stages of the tape-worms and the young embryos
of Gisophagostoma. The worms are called internal parasites. It is
easily understood, however, that being held in the cavities of the body
which have communication with the exterior, they are really external to
the body tissues, and only those embryonic forms which penetrate into
the tissues of the infested animal or host are true internal parasites.

As a rule the insects live on the surface of the body. They are
called external parasites. The exceptions are the larva of Gstrus ovis,
which lives in the nasal cavities, and Linguatula, whose young stage
infests various organs of sheep. Mstrus is usually classed with the
external parasites, and Linguatula is in sheep truly internal. As has
been stated, those parasites which in their young stages penetrate the
tissues of sheep are alone true internal parasites. Even these spend
their adult stages in the open cavities of some other host and then be-
come true external parasites, so that no one of these parasites is, strictly
speaking, an internal one throughout its life. That every parasite
should be an external one in its adult stage is a necessary condition of
its existence and of the perpetuation of its species, for it is only in the
open cavities that they can obtain sufficient air and food, and can mate.
From these cavities, too, the eggs and young can eseape for the infec-
tion of other sheep. The facility offered for mating and distribution
is the most important reason. In order to avoid confusion of terms
those parasites infesting the surface of the body will be called, in con-
formity with custom, external parasites; the others, which inhabit the
tissues of the body and its cavities, internal.

Though the animal organisms that infest the living bodies of sheep
be small, they are endowed with all the vital functions of life. Allcan
move, feed, feel, and reproduce. Noue of the worms can see or hear.
The insects are more highly specialized than the worms, All of them
have in the past become so adapted to their surroundings that they can
live in no other, and while sheep thrive better if not infested by para.
19

sites the latter can not live without sheep. The only exceptions are
those species which are also parasitic on other animals, as goats and
cattle. The modifications of organs which have arisen out of the needs
of parasitism are too many to givein detail. The great central fact of
their lives is that all the parasites have arisen from their kind, and under
favorable circumstances will reproduce their species, and that they are
to be treated as the originators of disease and not as the products of
disease.

The methods by which sheep become infested differ with the species. The
external parasites are usually transmitted by actual contact of sheep
against sheep. The parasites may, however, be dislodged from their
former. host and afterwards make their way to another sheep. The first
is known as mediate, and the second as immediate contact. The dis-
eases produced by the external parasites are true contagious diseases,
and should be regarded as such fully as much as any of the more act-
ively virulent maladies. The transmission with this class of parasites
is usually an active one; they-may, however, be borne from one sheep
to another by people, cattle, goats, or by locks of wool, when the trans-
mission would be passive.

(Estrus ovis, which seems to bridge the gap between the external and
adult internal parasites, differs from these groups in being able to act-

ively infest its host with its young, without an actual contact or inter-
mediate bearer. Lice, louse-flies, and scab insects may do this in a
less degree, butnot to that possessed by the Gistrus. The Cistrus larvae
are never transmitted by contact; they must mature, fall to the ground,
metamorphose, and emerge as adults before the females can infect sheep.
The internal parasites are passively conveyed into sheep along with
the food and drink consumed, and never actively enter into the trans-
mission. They may be conveyed either as eggs or very young embryos.

’ Gistrus forms the single exception.

The terms “contagious” and “infectious” can be applied to these
parasites. The former is applicable to those parasites which usually
transmit themselves to other hosts, tie latter to those which are trans-
mitted to their hosts along with food and drink. The young of Gstrus
have no agency in their transmission, and hence infect sheep.

Parasites are frequently said to invade the hosts which harbor them.
This is only true of those species which actively undertake migration,
as scab insects and sheep ticks. A few species invade the organs of
their hosts after the latter have been infected, thus: The larvee of Gstrus
crawl from the margins of the nostrils to the sinuses of the head; the
lung worms migrate into the lungs; the young embryos of Tenia mar-
ginata tunnel the liver; 7. cenurus tunnels the brain; Hsophagostoma
penetrates into the intestinal walls. Those internal parasites which
undertake active migration in the bodies of their hosts seem to form a
minor class in the parasitic world, those which lodge in the intestine
and dneta emntving into it forming the maioritv.
20

The ability to select their final lodgment belongs to each species, and
is the one character on which their own life and that of the species de-
pends. This is self-evident in the case of external parasites. After
hosts are once infected by the internal parasites and the young embryos
‘are endowed with activity, they either select their proper place while
being carried along by intestinal fluids, or force their way to it through
all opposing tissues and against all counter currents of fluids. Those
embryos which fail to reach these places finally die for want of the nec-
essary conditions of life. The very ability that is so absolutely neces-
sary to enable certain of the parasites to reach their chosen organ often
proves the means of their premature death. Tenia marginata cysts
invading the liver become lost in the mass of this organ and perish.
Multitudes of these parasites injure the capsule of the liver and cause
the sheep invaded to die long before they have matured sufficiently to
pass into dogs. The embryos of Gsophagostema often wander into the
mesenteries, the retro-peritoneal glands and liver, and perish.

Parasites escape from their ovine hosts either actively, e.g., the
young and adults of the louse-flies, lice, mites, and the larvee of Hstrus,
or passively as eggs or young embryos, the young embryos of the
Strongylus filaria and Tenia expansa, the completely segmented eggs of
the Strongylus contortus, and as eggs incompletely segmented. In
the latter case they are rejected with the excreta of the lungs or intes-
tines. A very few (the cystic tape-worms) escape only after the death of
their host by theintervention of some carnivorous animal which swal-
lows them with its food and liberates them from their imprisonment by
the processes of digestion. The death of the host is usually caused by
the carnivorain search of their food. The continuance of the parasites’
life into the adult stages depends, therefore, on the destruction of their
host. This fact is contrary to the usual rule of parasitism, which de-
mands that the host continues to live in order that the parasite may
live and reproduce its species.

The length of time and the stage of development at which parasites
infest their host varies considerably. Lambs have no parasites at birth.
Within a month or two after, they become infested by a few individ-
uals of certain species of round worms, and by external parasites.
From this time on they may harbor any of the species to which they
become exposed. It will be noticed that the commencement of infection
begins when the lambs first nibble grass. The louse-flies, lice, and scab
insects infest the fleeces and skin from generation to generation. Unless
it should subsequently be proven that the hair-lungworm (Strong-
ylus ovis-pulmonalis), and the stomach round worm (Strongylus contortus),
may also perpetually infest sheep, they harbor no other species through-
out their entire life cycles. Mstrus ovis is parasitical only in its larval
stage, and consumes mouths indeveloping. Becauseitcan not take nour-
ishment when adult, it is believed to pass a very ephemeral adult stage.
The broad tape-worm deyelops rapidly and disappears, its six-hooked
21

embryo apparently spending long seasons of suspended life functions
on the ground. The fimbriated tape-worm develops more slowly, con-
suming the greater portion of the year; its embryos may exist on the
ground for indefinite periods. The cystic tape-worms pass indefinite
periods as cysts in sheep, depending on their resistance to the vital
forces of the organs infested and upon the date of their liberation from
imprisonment. The life cycle of the liver flukes seems to be completed
ina few months. The majority of the round worms seem capable of
withstanding the elements while scattered over the pastures for indefi-
nite periods, either as ova or partially and completely developed
embryos. Their cycle of life in sheep is of variable periods, depending
on the species. CMsophagostoma, some of whose émbryos invade the
intestinal wall, offers a retarded development lasting through months.
Other species develop more rapidly. The exact cycle for each species
has not been determined, but most of them become adult in less than
six months, some in less time than three.

The seasonal appearance of each species depends on its life cycle,
the average temperature and the humidity of the season, and the age
of the lambs. Spring and fall seem to offer the most ontbreaks of dis-
ease produced by parasites. Summer and winter also have their spe-
cial parasitical diseases. Sheep-ticks, lice, and scab are more prevalent
in winter when the sheep are closely herded in yards or barns, and when
they are covered with heavy fleeces. The gad-fly occurs most in June
and July, but in milder climates it evidently flies the greater part of
the year. The disease it develops is more prevalent in older sheep,
yearlings being the youngest that show distinct signs. The broad
tape-worm infests young lambs early and causes their disease in a very
few months. March lambs harbor adult worms in May and June, and
May lambs in August. The fimbriated tape-worm also infests lambs
early, but does not produce its worst effects until late fall and winter.
The liver flukes generally appear first in summer and fall. The round
worms appear in young sheep of three months and upwards. The ma-
jority of those that produce disease develop it as they grow adult. The
thread lung-worms (Strongylus filaria) infest lambs, and epidemics due
to them usually occur from spring to fall. The hair lung-worm, on the
other hand, develops slowly, and while their presence can be detected
in the lungs of young lambs it is the lungs of old sheep which show the
greatest amount of changes due to their invasion. Asa rule warm,
moist seasons are most favorable to their development. The climate of
the United States so varies from North to South and East to West that
no exact seasonal appearances of the various species can be given. Most
of the species seem to be present in sheep in greater or less numbers
the year round. The most important factors in the time of outbreak of
different diseases seem to be the age of the hosts and the cycle of life
of the parasite.
22

-The destructiveness of each species is dependent on the numbers of
the invading parasites, the organ invaded, the method by which they
produce disease, and the age of the host. As a rule, most parasites
produce disease by their numbers, each causing its infinitesimal amount
of annoyance. The sheep-grub, the broad tape-worms, Dochmius cer-
nuus, and Tenia cenurus, are notable exceptions to the rule. But
few individuals of each of these species are found invading the organs
of sheep. Their destructiveness depends on the character of the
annoyance produced and on the organ invaded. <A few of nearly all
species may infest sheep, and seemingly cause no loss, but when any
of the factors favoring the development of either of the species appears
they increase innumerably and destroy the lives of their hosts.

Parasites effect injury to the health of sheep in many ways, some of
which are very evident to all, while others are indefinable and illusive.
The injuries effected by sheep-scab, by the hair lung-worms, and by
Cisophagostoma, are easily discovered; but the injuries produced by the
tape-worms and various species of round worms can not always be de-
tected in the intestinal walls. In these the method of determining dis-
ease is not by testing the various organs by the microscope or chemical
analysis, but by comparing the patient with a healthy animal of the
same age in action, appearance, weight, etc., and by comparing the
organs of the patient with an actual or assumed standard. In these
ways the effects of the subtle diseases produced by the parasites are
learned and just allowance made for their importance.

Most parasites mechanically injure tissues. They may either force
their way through soft tissues as the cysts of Tenia marginata, break
through the structure of lung tissue as Strongylus ovis-pulmonalis, en-
ter into the intestinal walls as (sophagostoma, or lacerate the tender
mucous membrane as Dochmius cernuus. The adult tape-worms seem
to irritate the intestines, derange their functions, and cause nervous dis-
turbances. Dochmius cernuus and perhaps Strongylus contortus seem to
abstract blood. Other round worms may live on the intestinal contents.

The destruction caused by the different diseases produced by para-
sites is varied. Seab, lung-worms, flukes, and tape-worms often destroy
entire flocks. The ravages of other species are less patent. There is
no doubt, however, that each causes more trouble than has yet been
assigned to it. The least destructive of the species common to sheep in
this country seems to be Trichodectes sphcerocephalus, Strongylus jilicollis,
S. ventricosus, and Trichocephalus affinis.

No rigid system has been adhered to in the succeeding pages. Nev-
ertheless, a certain plan of arrangement and treatment will be noticed.
The highest insects in the zoologic classification precede. These are
followed by the Acarine or scab mites. The Helminths, embracing
the Platoda or flat worms, and the Nematoda or round worms, follow in
turn. A systematic classification of the worms among each other is not
closely adhered to. It may be noticed further that such an arrange-
23

ment permits of a second subsidiary treatment of the subject by group-
ing the parasites together as regards the organs they infest. The vari-
ations arising are due in part to the antagonism between the two ar-
rangements adopted. The above plan was adopted more for conven-
ience than for its scientific accuracy from any single point of view.
Concluding, the author desires to give due recognition to all sources,
from which he has drawn in preparing this work. The chief sources
of information have been the admirable works of Leuckart, Die Mensch-
lichen Parasiten, 1868; Raillet, Elements de Zoologie, 1885; Neumann,
Traité des Maladies Parasitaires, 1888; and A. E. Verrill, Parasites of
Domestic Animals, Rep. Conn. Board Agriculture, 187071. An en-
deavor has been made to mention every other source in the text.

MEASUREMENTS.

The following tables will assist the reader in reducing the measure-
ments given in one denomination to those in another.

Metric system in medicine.

Grams
1 grain or 1 minim equals.-..-- 12-2. een ne cece ce eee cee nee ne cence neeees 0. 06
15 grains or 15 minims equal -.......----..----.-- Cols rel aS Sica cuayaynrayScrmjereciaraiels 1. 00
1 dram or 1 fluid dram equals ........ 2.200 cee eee ee eee cece ee cee eee rece eens 4.00
1 ounce or 1 fluid ounce equals...-.. 2... eee eee ee eee eee eee ee sae 32. 00

The cubic centimeter may be considered identical with the gram for
water or aqueous solutions.

' Metric system in measurement.

: Inch.
Dmiebor OC WAlS s wists rsniein te pcisaiasge BETyESEEN OSs SRERREReSEeRKs aces 39, 37
1 céntimeter equals scsee. cnc case steed sasices ee eeewuere cececes . 3937 or 2
1 millimeter equals ..--....2-...22--.---- Ghee wewerscexeseeeenls .03937 or as
One-hundredth millimeter equals...... +... 2-2-2 2-22 eee ee ee eee - 00039 or x55
One-thousandth miliimeter OQUAIS: i cisccec asus aremerse Nemes es - 000039 or zstuo
25 millimeters equal...... 2.2.2. 2 lee eee ee ne cence eee eee 1 nearly.

OTHER MEASUREMENTS.

¥or approximate measurements a liter (2.113 pints) may be consid-
ered equivalent to a quart; a kilograin to 22 pounds avoirdupois.

When graduated measures of weight or volume are not at hand, the
flock-master may use some of the common household utensils. Pint
and quart bottles, so called, should be tested, as they vary in size.
The pint contains 16 ounces, or abouta pound in weight. The smaller
bottles are known as 2, 4, 6, 8, and 12 ounce bottles. Vials are quite
common, those made to contain 1, 2, and 4 drams being most abundant.
A set of bottles can always be obtained at the drug-store and the size
marked on them. It is far better, however, to buy a set of graduates
and other measures, for they are of daily use. Common tumblers con-
24

tain from 8to10 fluid ounces; tea-cups, about 5 fluid onces; wine-glasses,
about 2 fluid ounces; tablespoons, half a fluid ounce; dessert spoons, 2
fluid drams, and teaspoons, 1 fluid dram.

In spite of the fact that the use of the metric system has been legal-
ized in the United States, so deeply is the old English system engrafted
upon the customs of our people that there will necessarily be a con-
fusion of weights and measures until the use of the former is made
compulsory. This system is so easy to learn and so easy in practical
application that it will certainly supersede the other in use, as it hasin
the continental countries of Europe.
THE SHEEP GADFLY—GRUB IN THE HEAD—NASAL
wg CATARRH.

CESTRUS ovis, Linn.
Plates I, II, and III.

The popular names of this well-known parasite of sheep convey to
the reader its epitomized life history, long known to veterinarians
and farmers. Though the life history is a comparatively simple one,
there are many of its details which are not only unfamiliar to the aver-
age shepherd, but some of which are unknown even to those who have
made a special study of these pests.

The “Sheep Gadfly,” the parent of the “Grub in the Head,” is,
when flying, so small and so quick in its actions that itis very difficult
to see, and still more difficult to catch. The greater proportion of
specimens in collections have been raised from the grubs, ¢. ¢., the adult
grubs are collected and placed in a net-covered box, the bottom of which
is covered by a couple of inches of damp sand. In a few minutes they
bury themselves in the sand, and in from three to four weeks they re-
appear as flies.

C. V. Riley (Insects Missouri, First Annual Report, 1868, p. 161) de-
scribes the fly (Plate I, Fig. 11) as follows:

In this stage it looks something like an overgrown honuse-fly. The ground color of
the upper part of the head and thorax is dull yellow, but they are so covered with
little round, elevated black spots and atoms (scarcely distinguishable without the
aid of a magnifier) that they have a brown appearance. The abdomen consists of
five rings, is velvety and variegated with dark brown and straw color. On the
under side it is of the same color, but not variegated in the same way, there being a
dark spot in the middle of each ring. The feet are brown. The under side of the
head is puffed out and white. The antenn are extremely small and spring from two
jobes which are sunk into a cavity at the anterior and under part of the head. The
eyes are purplish brown, and three small eyelets are distinctly visible on the top of
the head. It hasno mouth, and can not therefore take any nourishment. The wings
are transparent and extend beyond the body, and the winglets, which are quite largo
and white, entirely cover the poisers. Its only instinct seems to-be the continuation
of its kind. It is quite lazy, and except when atlempting to deposit its young its
wings are seldom used.

The male is about as large as the female, but may be known by its
relatively narrower forehead or space between the eyes. Catching a
male at large would be a chance operation, for though they fly to mate
with the females around the sheep-yards and pastures, they never make

their presence known by disturbing sheep.
20
26

Brauer (Monographie der Gistriden, p. 15) records the size of the male
and female at from 10 to 12™™, or about two-fifths of an inch; the width
between the eyes of the male at 1™™ or one-twenty-fifth of an inch,
and of the female at 2.5™™ or one-tenth of aninch. The length of the
wing is 9™™, nearly two-fifths of an inch. ,

Distribution.—The species occurs all over the world wherever there
aresheep. Itis now too late to learn ifit was indigenous in this country,
but we may believe that it was introduced with the earliest flocks im-
ported, whether in Mexico or on the Atlantic coast. Brauer, in 1863,
stated that it had then lately been introduced into Chili, South America.

Life history and description of larva.—The interest of the flock-master
in this species begins when the fly buzzes around the noses of the sheep
and deposits its young just within the opening of the nostril. Many of
the older writers on this subject supposed that the fly deposited eggs,
but Brauer (0. ¢., p. 154), in agreement with Joly and Dufour, pointed
out that the genus was one which deposited their young alive. Accord-
ing to Riley (0. c., p. 164) Samuel P. Boardman, of Lincoln, Ill, men-
tioned the two following independent discoveries: John Brown, “ Old
Ossawattomie,” stated in the Ohio Farmer about 1851 that he saw the
fly drop the perfectly formed and living grub in the nostrils of sheep.
About 1861 Dan Kelly, of Du Page County, Ill, made the same discov-
ery, and records the fact in the Prairie Farmer, October 14, 1865.
Boardman, in 1867, received a letter from Mark Cockrill, of Tennessee,
who wrote of having made the discovery years previous. Riley claims
(0. ¢., p. 165) that he obtained living maggots from a fly in 1866.

The young larva, having been deposited within the rim of the sheep’s
nose, soon attaches itself by means of the hooks (Plate I, Fig. 6), and
begins to make its way upward into the nostrils. The smallest specimens
collected by the writer are shown in Fig. 7e, natural size, and are not
much larger than when first deposited ; for the difference between their
size and that of eggs deposited by flies even smaller than Gstrus ovis
is inconsiderable. These small larve are in their first stage of growth.
They are little, white, elongated bodies, less than 2™™ long, ¢. ¢., about
one-twelfth of an inch (Figs.1 and 2). But little of their structure
can be seen except with a lens. They already show the division of the
body into eleven segments, two well-defined hooks (Fig. 3a, a), and two
minute terminal breathing pores (Fig. 4a, a). The ventral surfaces
(Fig. 2) show the little spines which later on are to become strong
thorns; some of the spines on the sides are relatively bristle-like and
- longer in proportion than they are later on. In their second stage of
growth (Fig. 7c, c) all the characters are well defined. The skin is
- white and so translucent that the digestive organs, the respiratory ap-
paratus, and the fine filiform nerves and their ganglia can be readily
made out; the spines on the abdomen, the hooks, and the stigmata are
all more pronounced. In the third stage—that of the mature larva
27

ready to undergo its change into a fly (Fig. 7a, a, a, and b)—the charac-
ters outlined in its first stages have been perfected. It is this stage
that is commonly seen by those who split open the head of an affected
sheep. The mature grub averages over 20™ in length and 7™™ in
width, or about three-fourths of an inch long by one-third of an inch
wide. Its width and length when measured depend much upon its
state of contraction. Its back is very convex, its abdomen is slightly
curved but generally flat, its outline is a very elongated oval, with an
acute head and obtuse posterior end. Half-grown specimens are more
pointed at the ends and decidedly flatter on the abdomen. From the
young to the mature larval state there is a decided change of color.
At first they are white and semi-transparent. They quickly grow
whiter and soon after take on a tinge of yellow, which, as they mature,
grows darker and darker. Then, too, on the back of every segment,
except the first and last, a dark narrow band appears which eventually
changes from a brown black to a dead black. These bands are rather
narrower in front, increasing in width backward. On the side of each
segment below these bands there is, in mature specimens, a row of dark
dots. The spines show the same changes, at first white, then tipped with
brown, and finally changed to black. The spines occur only on the
abdomen and the closely adjacent edge. They all point backward and
assist the grub in moving around.

When the larva is mature it escapes from the nostrils, falls to the
ground, bores into it for an inch or two, and, according to Riley (0.
¢., p. 162), contracts during the next forty-eight hours to half its for-
mer size, becomes smooth and hard and of a black color, tapering as
in the larva towards the head (Fig. 14). It remains in this state
three or four weeks, or according to some authorities from fifty to sixty
days, depending on the weather.’ When the fly has matured within
the case it pushes off a little round cap, ascends from the ground through
the hole left by the larva in its descent, and emerges into day to com-
plete the cycle of its existence.

‘The office of the fly seems to be merely to reproduce its kind. On ac-
count of its rudimentary mouth it is unable even to eat. After emerging
the fly crawls upon some neighboring grass or twig and rests there until
its wings and body have hardened. During the first part of its life, ac-
cording to Brauer (0. ¢., p. 149), it is very sluggish, sitting around in the
cracks and crevices of the walls of sheep stalls, and is so dull that it
must be dragged out. When placed on the hand it seldom flies off.
This dullness vanishes as soon as the fly has reached pérfection and the
right temperature of the air comes. It is then off with a whirr, first
vertically in the air, and then in the direction of the flocks.

The effects it produces on sheep and how and where the injury is in-
flicted may now be stated.
Bracy Clark, an English veterinarian, iuseaiwa the effect of the attack
28

of the fly in Transactions Linnean Society, 1797, vol. III, p, 315, as
follows :

Early symptoms.—The moment the fly touches this part (the nose) of the sheep,
they shake their heads and strike the ground violently with their fore-feet. At the
same time holding their noses close to the earth they run away, looking about them
on every side, to see if the fly pursues; they also smell to the grass as they go, lest
one should be lying in wait for them. If they observe one they gallop back, or take
some other direction. As they can not, like the horses, take refuge in the water, they
have recourse to a rut, dry dusty road or gravel pits where they crowd together during
the heat of the day with their noses held close to the ground, which renders it diffi-
cult for the fly conveniently to get at the nostril.

This description of the action of the sheep when attacked = the fly
is correct in all but one or two minor points. The sheep’s actions when
running indicate that they are taking every means to shake off and
dodge a single rather than a number of pursuers. If this quotation
had also described the sheep huddled under buildings, along fences,
under rock ledges and shade trees, holding their noses close under their
fellows, it would have completed a picture familiar to every farmer or
flock-master.

The fly only works during the heat of the day, while early in the
morning and late in the evening the sheep seem to enjoy feeding in
freedom from its annoyance.

Pathology.—The young larva deposited in the nostril of the sheep im-
mediately begins its migrations upward into the dark passages of the
nose. It progresses by means of its hooks and spines. By firmly fix-
ing the hooks into the mucous membrane it is enabled to draw up the
rear part of its body after it, and by pushing upon the spines of the
abdomen it holds itself in place while it thrusts out its head for a new
hold. Theonly appearance of limbs that the larva has is the two rows
of prominences along each side of the abdomen, as shown in Fig 13. In
this method of progression lies one cause of irritation to the sheep, viz.,
the hooks sink into the mucous membrane and not only irritate it, but
cause minute points of hemorrhage which are afterwards indicated by
very minute black dots scattered over the surface of the nares or in-
ternal nose. Whoever has felt the tickling and itching of a fly at the
entrance to, or a foreign body in the nose, can imagine some of the sen-
sations which induce the sheep to make such attempts to escape its foes.

As the larva grows in size it finds its way farther into the recesses of
the nose, and by following the grooved passage (see Plate IIJ, Figs. 1 and
2) penetrates into the furthest chambers. Fig. 1, », n, shows the young
larve wandering over the turbinated bones ants in the main passage.
One of these larve, advanced in size, is shown at 7 in Figs. 1 and 2 fol-
lowing the direction of the channel marked by the straw 0, 0, which
emerges into the frontal sinus of the head, k. The larve may also wan-
der among the windings of the superior turbinated bones g, and finally
growing to such a size that they can not escape, become entrapped
there. The same may happen when they wander through the small ori-
29

fice, near but below that leading into the frontal sinus, which leads into
thesuperior maxillary sinus. (See Plate II, a, b.) A bit of straw has been
inserted into the orifice to show the place of opening. From these places
the larve never emerge, but after maturing undergo calcareous degen-
eration. Those that arrive in the frontal sinuses seem to thrive, and at
the proper time are able to retreat through the orifice they first trav-
ersed and are finally sneezed to the ground. This history and the fig-
ures illustrating it, which have been drawn from nature, should satisfy
sheepmen who have thought that because the grubs were in the head
they must be in the brain. A glance at Plate III, with its three larvee
in the sinus (there were originally seven in the head which the artist
figured), will show that there is a bony partition, a, a, a, between the
brain and the larvee. This is also the case in regard to those small larvae
which wander among the intricate windings of the upper turbinated
bone, g. The larvee of the Gstrus, or the grubs, never do and never can
penetrate into the brain. !

If one may judge from the black dots indicating a previous hemor.
rhage scattered over the mucous membrane, the irritation set up by the
wandering embryos is very considerable. In the sinuses of heads which
contain older embryos other changes are to be noticed. They are filled
with catarrhal matter which has been produced by the irritation of the
larve, and the mucous membrane is greatly thickened. These changes
may also be observed over the turbinated bones, g, the greatest changes
occurring in the superior, the one next the brain. The membrane —
which covers the latter is the one in which the nerves of the sense of
smell are distributed, and a thickening of the membrane must greatly
interfere with this sense. This is no small matter, for it is mainly by
this sense that the sheep separates its food from other herbage.

In addition to the catarrhal product and thickening of the membrane,
it has been noticed that the membrane near the base of the turbinated
bone—near m—is sometimes very dark colored. At this point the
bone is exceedingly thin and pierced by a number of holes through
which the olfactory nerves, or nerves of the sense of smell, pass. It is
not unusual to find the membranes of the brain in the immediate vicin-
ity blackened by minute dots, indicating a previous inflammation at
this point. This affection of the membranes is probably caused by an
extension of the inflammatory process from the nasal cavity.

When the larve become entrapped in the maxillary sinus they ex-
cite the same catarrhal secretions and thickening of the membranes as
elsewhere, which finally fill the cavity, the outlet of which is at the top.
All this irritation is due to the insertion of the claws and scratchings
of the abdominal spines. The iarve live on the material in which they
move. . They seem to obtain plenty of air even in the most crowded
recesses, They continually cover and uncover the breathing pores
(Plate I, Fig. 10a), and in so doing keep them cleaned of all foreign
30

material. Bracy Clark says that they make an audible snap in doing
this, but the writer has not heard it.

Late symptoms.—The chief symptom of the disease caused by these
larve is the catarrhal discharge on the affected side of the nose, which
gives rise to one of the popular names of the disease, “snot-nose.”
Even this symptom may be absent when but few larve are present.

Neumann (Traité des Maladies Parasitaires, 1888, p. 501) accurately
describes the symptoms of affected sheep as follows:

Three or four larve of strus are frequently found in the frontal sinuses of sheep-
which, during life, had never manifested any symptom. Itis only when these larvee
are numerous, and when they are quite well advanced in their development at the
commencement of spring-time, that they occasion morbid troubles. The latter begin
by a discharge, often unilateral, which is at first clear and serous, then thick and
mucous. Frequently there is sneezing and snorting, accompanied by the expulsion
of mucus and sometimes of Gistrus larve. Later the animals turn the head back-
ward, often shake it, rub the nose against the ground or some other object within
reach, or with their front feet. As the malady gradually advances the sheep go with
lowered head, lifting the feet high as if they were walking in water. Sometimes
they quickly raise the head, carrying the nose to the wind, and then bend it back-
ward convulsively. From time to time they stagger and are seized with vertigo, but
do not turnin a circle. In severer cases there is difficulty of breathing, the first res-
piratory passages being obstructed by the larve or the inflammation of the mucous
membrane. The eyes are red and watery. The disease may be still further compli-
cated. The sick lose appetite and rapidly grow poor; they grate their teeth; a
frothy saliva runs from the mouth; their eyes roll in the sockets; convulsions arise
and finally death ensues, sometimes within six or eight days after the appearance of
the first symptoms. ;

But the disease is rarely so fatal; it lasts longer, and the larve having been suc-
cessfully cast out, the symptoms generally become more favorable and by degrees
completely disappear.

This affection has sometimes been mistaken for ‘‘gid,” or “‘turn-sick,” due to Ce-
nurus cerebralis, whence the name “‘ false gid,” or vertigo of @strus, which has been
given to it. Confusion will be avoided by recalling that turning in a circle doés not
take place in the present disease. The latter is nearly always accompanied by nasal
discharge and snortings, which do not appear in true “ gid,” and which, besides,
show themselves only in young subjects.

Occurrence.—The larve of Gstrus ovis may be found in the nasal
cavities throughout the year, and in nearly all stages of growth. This
is more especially true of the southern portions of the United States,
where the winters are mild and short. During the last winter and
spring, in January and March, larvee were collected of allsizes. Those
represented by natural-sized figures (Plate I, Fig. 7), were collected in
January at an abattoir in Baltimore, Md. Those figured in Plate III
were collected in May. From the older of these grubs a pair of flies
were hatched. The presence of very young larve during the past
winter is very interesting, and indicates the presence of flies at an un-
expected season. The usual time for the appearance of the fly is said
to be during the months of June and July, and the usual period of
pupation about two months. Two of my experiments showed that the
time might be three weeks or four weeks exactly. The larve ig said
31

to dwell in the nostrils about ten months. This statement has not yet
been verified. In very young lambs only young larve can be found,
while in yearlings the larva may be nearly adult, depending on the
exact age of the lamb and the time it was infeated. In yearlings the
frontal sinuses are small and the grubs easily escape detection. It is
in two-year-olds and older sheep that one finds the greatest infection.
In ewes the sinuses are sufficiently roomy to hold four or five larve
without crowding, but wethers, which have small horns, or bucks which
have very large frontal sinuses, can harbor many more. Rarely have
more than six or seven been found. Cases have been reported in other
countries where far larger numbers, as many as ten to fifteen, were
found. The largest recorded number seems to be from sixty to eighty.
The relatively small number discovered, and the comparatively large
size of the young when deposited, indicate that each female lays but
few young. Itis very unusual to find more than two or three larve of
the same size, especially if they be mature or nearly so. The young
larve are sometimes more numerous, six or seven of nearly equal size
being found together. The presence of all sizes of larve in the cavi-
ties is a piain contradiction to the statements made that the fy appears
only in June and July, for, no matter whether it takes ten months for
the larve to grow or not, young and middle sized and mature larve
found in the winter time could not all have been laid within the two
months indicated.

The more correct statement is that the fly may appear at any time
when the temperature is not too low, but that they are more abundant
in early and midsummer.

Preventive treatment.—Most authorities on this subject recommend
preventive measures, but practical application of the means and reme-
dies proposed is necessary to demonstrate their utility. A change of
pasturage or an avoidance of brush-fields does not seem to be advisa-
ble unless the sheep are turned into longer grass, for the flies are able to
follow the sheep wherever they may go.

A practical means of prevention consists in smearing the noses with
a mixture of equal parts of tar and grease, or of tar and fish-oil, or of
tar and whale-oil. The better way is to apply the preparation directly
by abrush. Some recommend smearing the salt and grain troughs with
the mixture, expecting the sheep while feeding to get more or less on
the nose. This method is not thorough enough. Fish or whale oil
alone is also recommended. Powers (American Merino, 1887, p. 300) ad-
" vises the following ointment for this purpose: Beeswax, 1 pound; lin
seed-oil, 1 pint; carbolic acid, 4 ounces. Melt the wax and oil together,
adding 2 ounces of common rosin to give body, then, as it is cooling, stir
in the carbolic acid. This should be rubbed over the face and nose once
in two or three days during July and August. He also recommends an
apparatus which may well be used by owners of first-class breeding
stock, and possibly others who own but few sheep: “ A canvas face-
32

cover smeared with this mixture (the above), or with one of asafcetida
and tallow, may be hung in such fashion as not to interfere with the
sight or with grazing and yet protect the lamb against the fly.” ,

Whatever the preparation used it should be periodically repeated
throughout the season during which the fly is known to trouble the
sheep, as the nosing of the sheep in the grass, the accumulated dirt, and
the rain all tend to make the preparation weaker and Consequently less
effective.

Old authorities recommend plowing furrows in the pastures, but these
will be beneficial only while the ground is dry and mellow. Removal
of the grub immediately after it has been deposited is impractical. All
grubs seen on the ground should be crushed. Heads of slaughtered
sheep should be cared for so that mature grubs can not escape to the
ground. Sheep yards should be periodically cleaned and sprinkled
with lime.

Medicinal treatment.—This seems to be hopeless. <A study of the life
history: of this parasite, which appears in the south at nearly all
seasons of the year, and of the anatomy of the recesses into which the
larva wanders, will convince one of the difficulties to be met with in
treatment. In the first place, even if a suitable remedy were found,
the sheep-owner would be compelled to resort to treatment as often as
he found his sheep troubled, and would have to treat each separately.
This arises from the fact that irritating famigations or sneezing pow-
ders, which pass into the lower part of the nose, would not affect the
larve in the sinuses no matter how violent thesneezing which they ex-
cite. Injections of irritating substances would also fail, excepting pos-
sibly in the hands of an expert, who, witha syringeand peculiarly bent
nozzle, could perhaps learn to inject into the nasal sinuses. Even in
that case failure would result in a certain proportion of cases, and the
maxillary sinuses could not be injected, nor would the larve in the re-
cesses of the turbinated bones be reached, In addition to all this,
most remedies which would kill the larve would injure the delicate
mucous membranes. For the flockmaster who may wish to try fumi-
gation or nasal injections, the folomaig recipe for fumigation as given
by Blacklock is reproduced : :

One person holds the head in a convenient position in front of the operator. The
latter, having half-filled a pipe with tobacco and kindled it in the usual manner,
places one or two folds of a handkerchief over the opening of the bow], then passes
the stem a good way up the nostril, applies his mouth to the covered bowl, and
blows vigorously through the handkerchief. When this has continued for a few sec-
onds the pipe is withdrawn, and the operation repeated on the other nostril.

Powers (0. ¢. p. 300) advises the following nasal injection, which should
succeed if any will:

It is best to procure at the drug store an elastic bulb syringe, price about $1, with a
small nozzle 6 inches long. Mix turpentine and linseed-oil in equal parts. Accustom

yourself to the action of the syringe so that you can gauge it accurately. Let the
affected * . beheld before you in a natural position, and carefully probe the nog-
33

trils with the nozzle until you find its bearing and depth (the nozzle will pass up a
surprising distance—six inches in grown sheep). Then charge the syringe, intro-
duce it to the extremity of the nasal cavity, and with a quick pressure inject about
a teaspoonful of the mixture. Withdraw at once and let the sheep recover some-
what from the effects of the shot, then treat the other nostril in the same way. * * *
Keep the mixture well shaken.

If the nozzle has a properly curved tip the injected mass will be more
likely to reach the larve. A trial on the head of a recently dead or
slaughtered sheep would give the operator more knowledge of the re-
quirements to be met than any description. Olive oil is preferable to
linseed.

Surgical treatment.—There remains but one other method of remov-
ing the parasites, and that is mainly surgical. Ifthe disease is appar-
ent on but one side (it may be on both), an opening is made into the
frontal sinus (see Plate II), with a special instrument called a trephine.
The opening is made on the dotted lines which connect the middle of
the eyebrows, and a little nearer the middle line of the head than the
eye. The operation is a tedious one, requires some skill, and if advisa-
ble to undertake with a number of sheep, should only be trusted to a
competent veterinarian. Moreover, the ultimate results are not such
that the operation could be advised in the majority of cases. Yet, as it
is the only means that offers any hope for the worst affected, Ziirn’s
directions (Raillet, Maladies Parasitaires, p. 504) for operating are given:

Cut off the wool which covers the forehead. Trace with colored chalk a transverse
line uniting the middle of the two superciliary arches (the eyebrows) and divide it
by another line passing at the middle of the forehead. The point of choice for tre-
phining will be in each of the two upper angles thus obtained without engaging the
lines which limit them. ‘The operation is performed according tothe ordinary rules
of surgery. From the opening made one often sees the larvw, which are extracted
by forceps. To kill others benzine moderately diluted with water is injected. The
flap of skin is then cleaned, applied to the opening, and sewed to the adjoining skin,
The whole is then covered with a turpentine coated leather plaster. The patient is
separated for a few days from other sheep. Sheep bear the operation with the same
impunity as they do marking the ears or other little operations.

Trephining may also be resorted to for the large cavities at the base
of buck’s horns, or for the maxillary sinus. The latter is a far more
difficult operation, and the vicinity of important nerves and blood-ves-
sels demands the 5 only a skilled veterinarian should undertake it. The
operation is, after all, only temporary in its effects, for the next larvee
laid in the nose will crawl into the same sinuses and create the same
disturbances as those removed.

Neumann’s advice, with which he closes his chapter on this parasite,
is, perhaps, the soundest to follow, except in the case of breeders of
valuable sheep :

At all times, if the number of animals affected is considerable, the malady should
be left to follow its course, and those which present the gravest symptoms should be,
sent to the shambles. , ;

23038 A P.

 

3
Fig.
Fig.
Fig.

Fig.
Fig.
Fig.
Fig.

Fig.
Fig.
Fig.
Fig.
Fig.
Fig.

wwe

SDT >

8.
9.
10.
11.
12.
13.

34

CEsTRUS OVIS, Linn.

PrateE I.

. Larva in the first stage. Dorsal view.
. Larva in the first stage. Ventral view,
. Head of larva in the first stage: a, hooks by which the parasite attacheg

itself to the mucous membrane.

. Tail of larva in the first stage: a, the stigmata or breathing pores.
. Hooks of well-developed larva.
. Hooks of very young larva.

Larve@ in various stages of growth; natural size: a, a, a, fully developed
larve in the third stage; b, three-fourths developed; cand d, yot younger
larve, possibly in the second stage; ¢, the youngest found, and those from
which figures from 1 to 4 were taken.

Cephalic end of full grown larva (Brauer).

Dorsal view of full grown larva (Brauer).

Caudal end of full grown larva (Brauer): a, stigmata or breathing pores,

Adult female fly with line indicating natural length (Brauer). >

Front view of head of the above (Braucr).

Ventral view of full grown larva, showing the spines which enable the para-
site to push itself along the smooth, soft mucous membrane.

Fig. 14. Pupa case dissected to show the imago or young fly within (Hailes),
Be 15. Fes s taken from fly noe
PLATE I

   

Bee Aad

n 14,
MAMA A ty
5 ~e

 

 

           
       
    

x
AAS
aaa

a =

. 33h &
SE, Ss

“s

»
y

 

   

     

  

a >
Lh all
we
TP etait
yy Yycek,
: Yee Vr

VF caters

      

Haines, del.

A.Moen & Co Lith Baltinone

CGSTRUS OVIS,
(The Gad Fly of Sheep.)

)
36

CESTRUS OVIS, Linn.

PuatTE II. -

Dissection of the head of a sheep to show the cavities into which the gad-fly grubs
penetrate. The straws indicate the passages from the cavities into the inside of
the nose: a, the superior maxillary sinus in which there is imprisoned the calci-
fied remains of a fully developed larva; b, the ridge made by the infra-orbital
division of the fifth pair of nerves; c, the infra-orbital foramen; d, an opening
into the nares; e, e, the frontal sinuses with young larvein them. The dotted
line f, f, indicates the level at which trephining, if it is done, should be per-
formed. Figure reduced to three-fourths of natural size,
 

‘ep ‘sawnEy

 

 

Il aLWTId
Fig. 1.

CEsTRUS ovis, Linn.

PLATE III.

Section of head of sheep made a little to the right of mesial plane: a, a,
a, a, a, section of bone surrounding }, the brain, and ¢, the nasial cavity;
d, the lower jaw bone; e, nostril; f, opening of tear duct; g, g, g, turbi-

“nated bones; kh, the posterior opening of the nasal cavity, and near the
opening of Eustachian tube; i, placed on the turbinated bone over a grub
in the groove leading to the frontal sinus; k, the frontal sinus; J, the nasal
sinus; m, the thin perforated plate of bone called the cribriform plate; a,
n,n, larvee of @strus ascending the nares and wandering about its surface;
i, one ascending to the sinus; %, opposite three, nearly mature larva in the
sinus. Figure reduced to three-fourths of natural size.

Outline drawing of the skull surrounding the frontal sinus after removal of
part of the turbinated bone, lettered as in Fig. 1; 0, 0, straws passed
through the channels conuecting the nares with the sinuses, marking
the path by which the larva reaches the sinus; p, cut ends of the removed
bones.
  

ACY] Oye uaOHY
“yap ‘sauimey

    

WI @LWId
THE SHEEP-TICK OR LOUSE-FLY--PHTHIRIASIS.

MELOPHAGUS OVINUS, Linn.

Plate IV.

One of the best known of all the external parasites of sheep is the
sheep-tick, Melophagus ovinus, Linn. This pest isa very common one in
the Eastern States, and although it seldom causes any serious damage
either to the sheep or to the wool, it is at all times an annoyance, and
occasionally causes decided losses to the flock-master.

This tick, like a majority of the parasites of the domesticated animals,
was introduced into this country from Europe. The name “ sheep-tick,”
though not a misnomer, as every one knows what a sheep-tick is, is
misleading. So much do they resemble the true ticks that they are
often classified together. The most superficial study will, however,
serve to show their differences.

Description.—The sheep-tick is a wingless fly jay but six legs,
whereas the true ticks are more closely related to spiders, and have
eight legs in their adult state. The adults are less than a quarter of -
an inch long, and have a short, flattened, bristly, leathery body. The
head is slightly wider than the thorax, into which it is sunk. They
have very short antenne, which are sunk in sockets in the face; the
proboscis is tubular, and is protected externally by two flat, dlongated
bristly pieces, the labrum; its end is armed with teeth. The thorax
or limb-bearing portion of their bodies is nearly square when looked at
from above. It is composed of three pieces, the middle being the one
seen on the back. The legs are very stout, covered with bristles, and
each is provided with two strong, sharp claws. The last joint of each
foot bears a pinviform or feather-like organ whose office is as yet un-
determined, but is probably that of coiling around hair for better pre-
hension. There are no wings. On either side may be seen two small,
bristle-covered, round spots at points where the wings should be
attached. At the posterior outer corners of the thorax are two little
projections which remind one of balancers. The abdomen, usually
jarger in females than in mrales, is flattened and bag-like, and is as
large or larger than the rest of the body, especially after the louse-
fly has eaten, when the red blood sucked from its host may be seen
through its skin. Its skin is tough, unsegmented, semi-translucent,
and permits the abdominal organs to show through. On each side
there are seven stigmata or breathing pores. The anus is situated on

39
40

the ventral side and just behind the genital orifice. The sexes resemble
each other, but may be separated by their size and by the form of the
external genital apparatus.

In habit these parasites resemble lice living among the hairs of the
fleece, whence the name, louse-fly. They seldom remain attached to the
skin longer than a sufficient time to fill up with blood; this they suck up
through the proboscis with which they perforate the skin. They try to
evade capture by running into the wool, and when caught cling tena
ciously.

Life history.—The family of flies to which this parasite belongs is
truly wonderful, in that they bring forth their young as puparia. The
puparia of Melophagus are laid as flat, ovoid, chestnut brown, glistening
seed-like eggs, which are nearly one-third as large as the abdomen of
the parent, and contain an imperfectly developed larva within them.
The egg cases or pupa are marked by two rows of seven dots each on
one surface, a slight depression, indented by two dots in one end, and a
slight elevation at the other. The two dots are at the anal end. A
dissection of one of these, taken from a female, shows the pointed end
to be connected with a membrane, and to be the end through which ie
larva obtains food.

Some authorities say that each female produces but one or two of
these puparia; others say that they can lay about eight or nine during
their life-time. They lay one at a time in the wool. A portion of each
puparium will be found to be covered with a dry, dark substance, which

* came from the parent when the puparium was laid, was sticky, and glued

it to the surrounding hairs. This prevents the pupa, which becomes
hard, dry, and glassy, falling from the wool. The insect emerge,
with adult characters from the pups cases, through an opening in the
end of the case made by a round lid splitting off, and wanders into the
wool. Some of these eggs collected in the course of our investigations
hatched within four weeks at ordinary temperatures.

Occurrence.—These ticks, or their young, may be found on the sheep
at all times of the year, but appear to be most numerous in spring.
They are particularly noticeable at shearing time on the old sheep after
they are deprived of their shelter. At this time those that can do so
take refuge in the longer wool of the lambs, and prove veritable pests.
The others perish either from being eaten by the sheep, carried away in
the wool, or dropped to the ground. They frequently become attached
to the clothing and persons of people with whom they come in contact,
but they prove but a slight source of discomfort, as they are easily
caught and killed. It is not at all probable that they can exist many
days apart from the sheep, as they are unfitted by structure for any
other habitat. Their food consists wholly of the blood which they suck
from the sheep. They depend also on the sheep for warmth; in warm

spring days they may be found crawling near the ends of the wool,
while in the colder days they will always be found either engaged in
41

|| feeding or resting at but little distance from the roots of the wool. A
dozen or more of these ticks, which were moderately well fed when
taken from the sheep were, with some wool, placed in a cotton-stoppered
bottle and kept in a room with a temperature varying between 60° and
80° Fah. They all died in less than four days. The leanest succumbed
first, in about two days, while those that were better nourished grad-
ually grew sinaller and thinner, and lived little longer than the third
day. Others placed in wool over the damp soil of a geranium in a
flower-pot died within four days. On the other hand, some young ones
which were hatched out in a bottle were kept for nearly two weeks, or
until their daily feeding was neglected. To feed them they were placed
on the back of my hand. By this means I could, with a lens, watch
them bore into the skin and see the abdomen slowly enlarge as they
drew in the blood. They had some difficulty in penetrating the thick
skin, but usually succeeded by slipping their tube into a hair follicle,
At first no itching or irritation was felt, except a slight twinge when
the bills first penetrated the skin; but little swellings came on a day or
two later which itched for over a week. The itching was far more per-
sistent than with mosquito bites. They must in this way cause lambs
much discomfort. It was at first thought that a fluid could be seen
running from the parasite to the hand through the bill, but no more was
thought of it until the elevations began to rise and itch; then it ap-
peared certain that the little pests had secreted a poisonous fluid. The
office of this secreted fluid is probably to assist the flow of blood by
keeping it from clotting.

The above experiments show that the parasite spends its whole life
on the sheep.

Source of contagion.—The fact that this parasite passes its whole life on
the sheep, and that it produces but few young, are very important con-
siderations in efforts for exterminating the pest and preventing a new
infection. They indicate that if all are killed the sheep will not again
he infected except from other sheep.

Disease.—The injury sustained by sheep from these parasites varies
according to the number present. It arises from the itching and pain
inflicted by them when obtaining their food. A few cause but little
annoyance, and, were it not that these may become the source of future
multitudes, would be scarcely worth noticing. To lambs the annoy-
ance is particularly aggravating, as their skin is tender and the number
of parasites attacking them after shearingis unusually large. In older
sheep the irritation is the more noticeable towards spring. At thistime
the parasites are more numerous and the animals bite and scratch them-
selves oftener.

Medical treatment.—The well-known means of ridding the sheep of
these pests are the tobacco or other mixtures used for scab-dips. The
best time of the year to dip is at shearing time. Then the older sheep
can easily be handled and cleansed. The dipping should not be delayed
42

long after, for each additional day is one of torment to the lambs. The
lambs also should be thoroughly dipped. One dip is said to be sufficient
to kill the old parasites. However,a few of the pups may remain in the
fleece of the lambs. They should be thoroughly examined two or three
weeks after, and if there are any present they should again be dipped.
All the precautions taken in dipping sheep should be carefully ob-
served. The shorn wool should be stored where the young ticks which
may hatch from the pupa cases can not crawl back to the sheep. How-
ever, they seem to have great (difficulty in crawling, and may not be able
to go far. An experiment in which some of the pup became wet with
moisture from other ticks in the same bottle demonstrated that they
would not hatch, and indicates that the sheep bath will very likely kill
the inclosed larvee. ;

In The American Agriculturist, October, 1889, page 490, Mr. Joseph
Harris advises fall dipping for these pests. This is a good plan if the
sheep have become infested with ticks after the spring dipping by some
inadvertence of the master. He advises the use of tobacco, carbolic
acid, and kerosene emulsion dips. The carbolic acid dip is composed of
a pound of soap and a pint of crude carbolic acid to each 50 gallons of
water. Dissolve the soap in a gallon or more of boiling water, add the
acid and stir thoroughly. Keep the mixture well thinned, and do not
let it get into the mouths, nostrils, or eyes of the sheep. Hold each
sheep in the bath not less than half a minute.’

The formula for kerosene emulsion is as follows: Churn fresh
skimmed milk and kerosene together in the proportion of 1 gallon of
milk to 2 gallons of kerosene, either in a churn or by using a force-
pump until an emulsion is made. The method of using the force-pump
is to set it in the vessel containing the mixture and turn the stream
back into the same vessel. The emulsion will form quicker if boiling
hot milk is used. For dipping use I gallon of the emulsion for each 10
gallons of water required. Mr. Harris seems to think 20 gallons, with
a reserve of 10 gallons, sufficient; but he was evidently thinking of a
very few sheep. He did not use this emulsion, but a variation made
with soap, as follows :

Boil a gallon of water, dissolving a pound of soap in it; add 2 gal-
lons kerosene; churn the mixture until it emulsifies, or until all the oil
is “cut.” Use 1 gallon of emulsion to 8 of water. Mr. Harris ad-
vises dipping twice with an interim of two weeks.

Fifty gallons ot the dip will suffice for fifty sheep. Seventy would
probably answer for one hundred; but much depends upon the amount
of waste on account of the liquor being carried off by the fleece. The
recipe is very easily modified for ranching purposes.

The emulsion has already been advised for cattle lice in Bulletin No. 5,
Iowa Agricultural Station, p. 184, May, 1889, and for cattle ticks in
Insect Life, Vol. II, No. 1, p. 20, U. 8. Department of Agriculture,
July, 1889. Though the efficacy of this remedy against the various
43

kinds of insect parasites of domestic animals has yet to be tried in de-
tail, its importance in this field has already been demonstrated.

Preventive treatment.—The sheep should not be turned into the old
pens or pastures until a week after the first dip, by which time it may
reasonably be supposed that all parasites on the ground have died. To
avoid the chance of any recently hatched parasites getting from the
ground to sheep in places where the sheep rest, it is best to scrape out
and cleanse the pens. Animals recently purchased should always be
dipped before being added to the older flock.

By following ont a thorough plan of treatment, and by carefully
guarding the sheep from re-infection, the flockmaster should be able to
rid his flocks of this pest in a single season.
Fig.

Fig.

Fig.

Fig.
Fig.

Fig.

Fig.

Fig.

Fig.

44

MELOPHAGUS OVINUS, Linn.

Puiate IV.

1. Female sheep-tick: la, larva case, each natural size.

2. Male, dorsal view, X8: a, head; b, thorax; c, abdomen; d, limbs; e, oval
bristle-covered disks, which correspond to the points of attachment of wings
in other flies; f, rudimertary halteres or poisers.

3. Male, ventral view, X8: g, h, andi, the three segments of the thorax; k, the
external genitals.

4. Female, dorsal view, <8. ;

5. Larva case, X8: a, cephalic end; b, two rows each of seven shallow indent-
ations.

6. Foot: a, the two claws between which hangs b, the pinniform prehensile
organ; ¢, the tarsi, whose last joint @ supports the prehensile organ; e,
distal end of the tibia.

. 6a. Prehensile organ, x60: a, the segmented muscular portion included within

the tarsus; b, the flexible grasping portion.

.7. Front view of head: a, the compound eyes; b, the antenne sunk in cup-

like cavities; ¢, the labram which protects the sucking organ.

. 8. The sucking apparatus: a, the labrum; 8b, the orifice from which the tube

protrudes; c, the sucking tube.

.9. End of the sucking tube, X120: a, teeth by which the tube cuts its way

through the skin; b, rod upon which the teeth are set; ¢, tube which has
lateral orifice in it. Other details not shown.

. 10. External genital apparatus of female: a, spine-covered cap which fits over

b, the genital orifice above; ¢, two clusters of spines which seem to be for
clasping; d, the terminal of the seven pair of stigmata or breathing pores ;
e, anus. :

11. External genital apparatus of male: a, the two lateral of the three chit-
inous styles which surround the projecting intromittcnt organ; b, two
clusters of spines which seem to be claspers; ¢, stigmata.

12. Larva case, X6: a, case with the broken operculum inside; b, cephalic end,
showing line where the operculum splits off and the remains of a cen-
tral orifice through which nourishment was obtained by the embryo from
the parent; c, caudal end showing the two dots corresponding to the two
terminal stigmata.

13. Larva case with larva, X6: a, ventral view; b, dorsal view.
PLATE IV

11h

Ue eee
€
me
al

it

ie

 

Haines, del.

A Moen & Co. bith, Balti ce

MELOPHAGUS OVINUS,
(The Louse-fly.)
_ THE SHEEP-LOUSE—PHTHIRIASIS—LOUSINESS.

TRICHODECTES SPH ZROCEPHALUS, Nitzsch.
Plate V.

The little red-headed sheep-louse is not very abundant in this coun-
try, and easily escapes detection. It is, nevertheless, of sufficient
economic importance to engage our attention.

The genus Trichodectes, to which this parasite belongs, is classed by
scientists in the order Mallophaga, to which order the bird-lice belong.
They are said by Packard (Guide to Study of Insects, p. 554), to live
upon the hairs of mammalia and feathers of birds.

Deseription—The sheep-louse is quite small, about 1™™ or one-
twenty-fifth of an inch in length. The female is slightly longer and
larger. It is characterized by its reddish head and the pale, transverse
bands which cross the abdomen. Neumann describes the species as fol-
lows:

Its head is wider than long; truncated in front, the antennal band making the —
turn of the forehead which carries long hairs on its border. The antenns are hairy
and a little longer in the male than in the female. The abdomen carries sub-quad-
rangular median spots. The general color is whitish ; the spots and head are ferru-
ginous. Length of female 1.6™", and male 1.4™™,

This general description is very good, but would hardly serve to dif-
ferentiate this species from others without figures and comparative
descriptions. Entomological anatomists enter into very minute details
of description for determining these species, but a comparison of speci-
mens found with the figures in Plates V and VI will assist the farmer
more than a long technical description. As yet theonly form recorded
from sheep in this country is the one species, Trichodectes spherocepha-
lus, or T. ovis, which is a synonym. The following appear to be the
most marked differences between this and other species: The species is
generally smaller than others. The breadth of the abdomen is relatively
narrower, and that of the male seems to be more obtuse. The dorsal
sutures on the head (see Plate V, Fig. 2 ¢, e), are fainter in the middle.
The front of the head is more convex. The brown markings on the
head are all relatively fainter; those on the back of the male and
female increase from the first to the fourth and then decrease to the last
in a gradual manner. The claws of both anterior and posterior feet are
more nearly of the same size. The eggs (Figs. 6 and 7) are midway in
size between those of the two species figured on Plate VI. These eggs
have a cap marked by vertical striz, which constitute a generic charac-

45
48

TRICHODECTES SPH ZROCEPHALUS, N.

PLATE V.

In Plate V, figs. 1, 2, 3, 6, and 7, and in Plate VI, figs. 1. 2, 3, 5, 11, 12, 18, and 15
are equally enlarged, and present relative differences in size and form. Other parts
are also enlarged similarly for the sake of comparison.

Fig. 1. Male, natural length indicated by line.
Fig. 2. Female, natural length indicated by line: a, head; b, antennx; ec, face;
_ d, cheeks; e, e, dorsal sutures; f,f,/, legs; g, prothorax; h, metathorax;
i, abdomen; k, dark transverse bands; J, line of hairs on each segment;
m, m, stigmata or breathing pores; (fig.1), male genital orifice; o, female
genital orifice; p, female claspers.

Fig. 3. Young specimen just emerged from shell.

Fig. 4. Male antenna.

Fig. 5. Female antenna, ;

Fig. 6. Egg soon after being laid: a,cap with peculiar rod-like structure; J, line at
whicli the cap is to cleave off.

Fig. 7. Ege shell which has lost its embryo and cap: b, b, wool fibers.

Fiz. 9. Posterior leg.

. Head, ventral side: a, a, antenna; b, b, ventral continuation of dorsal sut-
ure; c, ¢, ventral suture; d,d,mandibles; ¢, maxilla showing through
the chitinous gular plate; f, the labrum.

Fig.11. Tail end of male, dorsal view: a, the last segment; b, the genital orifice;

ce, chitinous, hook-like appendages of the genital apparatus.

Fig. 12, Tail end of female, ventral view: a, the last segment; 6b, the genital and

anal orifice ; c, the claspers, :

7

Fig. 8. Anterior leg: a, coxa; 6, trochanter; c, femur; d, tibia; e, tarsi and claws.
9 é
0
PLATE V

 

Haines, del. TRICHODECTES SPH ZROCEPHALUS, A.Hoen & Co. Lith, Ballimore.
(The Sheep Louse.)
GOAT. LICE.

TRICHODECTES LIMBATUS, Gervais,
Plate VI, Figs. 1-8.

Description.—Trichodectes limbatus, Gervais—the Angora louse—re-
sembles 7. climax closely, but differs in specific details. Allthe brown
markings on T. limbatus are darker and wider; the head is slightly
more indented in front; the dorsal suture (Plate VI, fig. 2 e, e,) is more
pronounced; the head is wider in proportion to its length. The banded
margin of the abdomen is wider. The greatest difference lies in the
disproportion of size between the male and female of 7. limbatus, and
the character of the transverse bands of the abdomen of the male; the
abdomen of the male being shorter is relatively wider in proportion to
its length, and has a quadrangular appearance. The first band is nearly
straight and one-third shorter than the three succeeding, which are of
nearly equal length and convex anteriorly, concave posteriorly. The
fourth and fifth segments bear a second narrow band near the posterior
margin, The egg of this species is larger than that of T. sphwroceph-
alus or T. climax.

The marked differences shown between the bands of T. climax and T.
limbatus was a constant one in all males examined. This feature, in
connection with the difference in size of the eggs and the many minor
differences of form and color, seem to be specific. The males of these
species seem to offer the most tangible characters for separation. When-
ever other species of this genus are described particular attention to
the males should, on this account, be given. The females seem to ap-'
proach each other more closely.

Occurrence and disease.—The goat louse is common, and causes more
trouble to goats than the little red-headed louse does to sheep. When
present it occurs among the coarse hair along the back and sides of the
goat. It causes much discomfort and scabbiness of skin. If the ani-
mals are severely infected they become poor and thin. The Angora
goat louse caused, in the single flock in which it was seen, not only a.
severe scabby skin disease, but a loss of fleece. The whole back, sides,
and head seemed to be completely covered with the parasites, young
and old, and nits.

Treatment.—The disease caused by these parasites is of that class |
which is preventible, and it is inexcusable if it be allowed to continue.
The history in each case is that of infection from other sheep, goats, or
Angoras, as the case may be. As the parasites spend their whole lives
on these animals they may be killed on them and not be expected to

93038 A P——4 49
50

come again except from other animals of thesame kind. Yards, where
any of these animals are kept, should be sprinkled with lime and the
walls washed with diluted lye, or whitewashed before the animals which
have been treated are returned. This will ensure safety from any par-
asites which may have fallen to the ground where the goats have lain.
The treatment should be thorough. As these animals are small the
best method is to immerse them in tobacco water, thus insuring the de-
struction of every parasite and nit, even those on the nose, by immers-
ing them while holding the nostrils. If the hair is long on the Angora
they should by all means be sheared. If it is not desirable to dip them,
the selected remedy may be sopped on the skin and wool and thoroughly
rubbed in so as to wet the skin.

Medicines may be applied in three forms: in powders, as pyrethrum
or Persian insect powder, and tobacco dust; in ointments, as oil or lard,
with some added ingredient, and in baths, as the tobacco or arsenical
dips. Of these the first is the more objectionable and the least valuable.
The second is better, but not entirely successful. The third is the one
which should be used in the majority of cases, as it is the most certain.

The following recipes are among tliose in use, and are recommended
by various authorities :

A decoction of stavesacre seeds, 3 ounces to 2 quarts of water, to be
thoroughly rubbed in. (Neumann.)

A decoction of stavesacre seeds, 1 ounce to 1 quart of water or vine-
gar, or half water and half vinegar. (Finlay Dun.)

In powders, tobacco, pyrethrum, stavesacre and sabadilla may be
used, but the last two are not advisable.

Benzine 1 part, soft soap 6 parts, water 20 parts, or petroleum (kero-
sene) 1 part, sweet oil 10 parts. (Neumann.)

Schlegs’ mixture is recommended in Germany for its. efficacy and
harmlessness when prudently used. Arsenious acid one-half ounce,
potash one-half ounce, water 3 pints, vinegar 3 pints. (Ziirn.)

The most efficacious remedies are the tobacco, or the tobacco and
sulphur dips, advised for scab. For flocks of large numbers, nearly all
other recipes are unavailable.

Mercurial salves should not be used.

Ziirn advises tobacco 1 part, water 20 parts, or water 20 parts and
vinegar 10 parts, to be made into a decoction, and vinegar added after
cooling. The kerosene emulsion may also prove a valuable remedy. It
should be applied as directed for exterminating sheep-ticks, or by means
of a force-pump and spray-nozzle.

TRICHODECTES CLIMAX, Nitzsch.
Plate VI, Figs. 11-18.

The common goat, Capra hircus, L., is quite commonly infested by a
species of louse which has been identified by the writer as Trichodectes
climax, Nitzsch, and the Angora goat, Capra hircus,, var. Angorensis, by
51

one which seems to be Trichodectes limbatus, Gervais, or T. climax, var.
major, Piaget. The uame applied by Gervais is accepted, for the differ-
ences between the two appear to be specific and not varietal.

Description.—The characters of Trichodectes climax are: Head wider
than long, quadrangular, presenting a wide but shallow indentation in
front, at which the two antennal bands stop; antennz hairy, a little
longer with the male than the female; the first joint is larger and
shorter than the others; the second longer than the third; the abdomen
bears median spots, the width of which diminish as their length in-
creases. The last segment of the male carries two hairy cashions.
Head and thorax, reddish-brown ; abdomen, pale yellow ; spots, brown-
maroon; bands, blackened. Length, female, 1.6™™; male, 1.3™™. (Neu-
mann.)

The female of this species is broader and the male a little shorter than
in.the corresponding sexes of T. spherocephalus. The dorsal sutures of
the head are much darker and plainer; the edge of the head and ad-
domen are margined by a pronounced dark band. The differences
between the anterior and posterior feet are much more decided. The
dark bands of the back of the abdomen of the male seein to offer the best
characteristics, viz: They gradually increase in length to the fourth,
when they begin to narrow. Beginning next the thorax the first band
is narrow; the second, third, and fourth are wider; the succeeding are
narrower ; ‘posterior to the line of hairs on the second to the fifth seg-
ments are extra narrow bands, which are about equal in width. The
egg of this species is shorter and narrower.
Fig.
Fig.

Fig.
Fig.
Fig.
Fig.
Fig.
Fig.

52

TRICHODECTES LIMBATUS, Gervais.

Piate VI.

. Male, natural length indicated by line.
. Female, natural length indicated by line: a, head; b, antennw; ¢, clypeus;

d, checks; e, e, dorsal sutures; f, f, f, legs; g, prothorax; h, metathorax ;
i, abdomen; k, k, dark transverse bands; 1,1, lines of hairs; m, m, breath-
ing pores; n, male genital orifice; 0, female genital orifice; p, female
claspers; g, male genital hooks.

. Head, ventral view: a, antennw; b, mandibles.
. Posterior end of female, ventral view: a, genital and anal orifice; 5, glaapers

Egg: a, the cap; 0b, the line where it splits off.

. Antenna of female. :
. Anterior leg: a, coxa; 6b, trochanter ; c, femur; d, tibia; e, tarsi and claws.
. Posterior leg.

Trichodectes climax, N.

Figs. 11 to 18. Numbered and lettered for the same parts as Fig. 1-8.
PLATE VI

ORO eS,

{east Ey

 

Haines, del.

A.Hoen & Co. Lith. Baltimore

TRICHODECTES LIMBATUS,

TRICHODECTES CLIMAX,
(The Angora Goat Louse.)

(The Common Goat Louse.)
THE ITCH OR SCAB INSECTS—ACARIASIS—ITCH—SCAB.

SARCOPTES, Latr.; Psoropres, P. Gerv.; CHor1opTEs, P. Gerv.

Of all the diseases caused by external parasites those due to the scab-
making insects are of the first importance. The losses due to them are
very heavy, and are exceeded by those of no other external parasite,
and equal those of the most destructive of internal parasites. Owing
to the means used in preventing flocks from becoming infected, and to
the extermination of the pests by the proper use of efficacious remedies,
these losses are annually becoming reduced. It is to be hoped that in
the near future, through the exercise of proper sanitary laws, this most
tractable of all the parasitic diseases may be completely exterminated
in our country.

Scab is a disease due to the presence of minute insects which lead a
parasitic life on the skin of their hosts. - It is caused by the inflamma-
tion they excite in penetrating the skin, that they may procure food for
themselves and young, and suitable conditions under which the eggs
may be deposited and hatched and the young matured. The disease is
thought by some to be aggravated by a poisonous fluid secreted by the
insects, which adds to the intense itching.

The malady proceeds step by step with the growth, euneien and
decay of the innumerable insects which result from the acquisition of a
single fertile female or a few pairs of individuals, and the spread of the
disease, therefore, coincides with an increase in the numbers of the par-
asites, while the limitation of the disease follows their extermination.

There are at least three different species of scab-forming insects,
parasitic on sheep, and each species is not only specifically different
from the other, but the disease caused by each is different. This is
due to the variation in the anatomical structure and habits of lite in the
several species of these pests, which causes them to attack the skin in
different places and by different methods, and hence gives rise to the
various symptoms common to each disease.

These insects are known as Acari, and the diseases they cause as
acariasis. The various species parasitic on sheep are Sarcoptes scabiet,
de Geer, var. ovis; Psoroptes communis, Fiirst, var. ovis; Chorioptes
communis, Verheyen, var. ovis. Of these the Sarcoptes causes scab of
the head ; Psoroptes causes common scab, and the Chorioptes foot scab.

The life history of these parasites is in general very similar. They
attack the external skin of the animals in which they live by biting it.
Soon after scabs are formed. Under these scabs the insects lay their

53
54

ovoid eggs. After two or three days these eggs hatch, and in fifteen days

the progeny become adult. Each adult female is estimated to lay about
fifteen eggs, two-thirds of which produce females. When hatched the
young invade new territory and lead the life of their parents. The ex-
tension of the invading hosts is due to their migration and rapid propa-
gation. The disease usually spreads as a constantly growing patch.
The infected sheep sometimes scatter the scabs by scratching; these,
in turn, become new centers of infection. The multiplication of the
invading pests ceases only at the death of the host, or when they
are killed by the use of proper remedies. To illustrate the rapid
increase of the Sarcoptes, Gerlach, a scientist, computed that in three
months a single female would produce 1,500,000 progeny. He esti-
mated that each adult female laid fifteen eggs, of which ten were
females, and that the eggs became adults in fifteen days. The resultis
shown in tabular form as follows:

Females. Males.
First generation after 15 days produces... 10 5
Second ‘“ fe 30) tt we aii 100 50
Third ee Cf oi OH ite etal 1, 000 500 ©
Fourth ‘ “« 60 « # ----  - 10,000 5, 000
Fifth ee a 48. SE sg ae ---- 100,000 50, 000
Sixth st E~ SQ0) 086 ce ----1, 000, 000 500,000 —

This table presents a very moderate estimate of the rate of propaga-
tion. A microscopic examination of minute particles of scab shows
them to be teeming with young and old parasites, and would seem to
confirm the estimate given. As but few of the parasites may be trans-
ferred to a healthy animal, it is evident that up to the second month
but little advance in the disease will be noticed, but after that time the
tenfold increase every two weeks produces an enormous number of the
parasites and causes the disease to advance with wonderful rapidity.

THE HEAD SCAB.

SARCOPTES SCABIEI, de Geer, var. OVIS.

Description.—The insects which cause this variety of scab are almost
invisible to the unaided eye, and are among the smallest of the scab-
making insects. They are known as Sarcoptes scabiei, de Geer, var.
ovis. They may be recognized by their rounded or somewhat oval
bodies, their small heads, which are furnished with a biting apparatus,
and by the adult having four pairs of legs. The young have but three
pairs of legs. Other anatomical characters, which are differentin differ-
ent species, are present, but for the flockmaster these are unessen-
tial, as the species can be separated by biological characters which are
plainer and easily understood.

Disease—Head scab begins on the upper lip, aud about the nostrils ;
more rarely it may show itself for the first time about the eyelids and
55

ears. In these places there is less hair and grease, affording the pests
better opportunities of getting at the skin. From these starting-points
the scabs spread over the forehead, cheeks, eyelids, and occasionally
over the space under the jaw. In badly infected sheep the disease may
sometimes extend to the fore limbs, under the belly, around the joints,
and especially between the folds of the knees, hocks, and pasterns.
Sheep with coarse dry wool are more likely to suffer this extended
invasion than those with fine, oily, and soft wool. Long wool seems
to offer a barrier to its progress, for the invasion of parts covered by
short wool is much morerapid. The demarkation between the invaded
parts of the head and the healthy wool-bearing portions is quite abrupt.
In coarse-wooled breeds the disease may rarely cover the entire body.
The first indication of the disease is shown by the sheep in rubbing or
scratching its head. The intensity of the itching is manifested by the
violence of the sheep’s action. The fist that can be seen on an infected
spot is little elevations with soft centers. These elevations break of —
themselves, or through the rubbing they receive, and from them runs
a watery fluid that in drying forms little hard bunches which stick to
the skin and adjacent hairs. These little elevations are made by the
parasites, which sink themselves into the skin. Here the parasites find
suitable food, grow and produce their young. These migrate and pene-
trate into the skin as did their parents. Thus the disease spreads
slowly as the parasites increase. Finally, as they become more numer-
ous, they cover the invaded skin with a thin layer of scabs. As the
diséase advances the little scabs not only run together, forming one
mass, but they become thicker, whitened, and hard. Later they run
together over the nostrils, lips, face, cheeks, forehead, eyes and ears,
and form a dry, hard, thick, seabby mass. By repeated rubbings this
scab breaks up, and the skin tears, cracks, and bleeds. Later the
wounds heal and scars are formed. When the scabs cover the eyelids
the latter close up.and the animal:becomes practically blind, being un-
able to find its way or to see food. The insects are to be found in the
moist layer underlying the scabs.

Source of contagion.—The insects which cause the disease have been
derived from other sheep with which the recently infected flock may
have come in contact, or which may have left a few parasites on some
brush or stick, or in some trough with which the uninfected flock came
in contact. The methods of infection are various, but he who under-
stands that these parasites always come from some where else, and
always from some infected flock, will soon learn what to do to prevent
his sheep from becoming infected. The variéty of Sarcoptes parasitic
on sheep is similar to the variety living on goats, and it has been ex-
perimentally proven that each variety may be transferred and will live
on either animal. Some of the varieties living on other animals may
be transferred to sheep, but they do not thrive. It is not at all prob-
able, Ee that sheep are infected from other animals than sheep.
56

Diagnosis.—Head scab can not well be confounded with any other
variety of scab. The seat of the disease and the presence of the para-
site, which is scarcely visible to the unaided eye, are sufficient to defi-
nitely diagnose the malady.

Prognosis.—This variety of scab is one of the most amenable to treat-
ment. Being mostly on the head it is easy to reach with remedies. If
treated it will prove of little loss to the flock-master, whileif allowed to
take its course it will continue for a long period, gradually growing
worse and rendering the patient more and more unsightly and ill-fa-
vored. It can cause severe inflammation of the eyes and ears. It can
hinder the fattening of the animal and cause extensive alterations of
the tissues of the skin. By affecting the health of the sheep, it will not
only decrease its weight but mee lessen the amount of wool pro-
duced.

Medical treatment.—The worst feature of firaating the disease is, that
treatment for a complete eradication seems to be extreme and out of
proportion to the end to be attained. Curative treatment always yields
good results when the application is rational. In the early stages of
the disease, when the scabs are just formed, simple applications of scab
dips or ointment are all that are needed; in cases of longer standing it
‘ will be found necessary to first soften and loosen the scabs with some
kind of grease or oil, and then to remove them with some alkaline solution
orsoap. The thin oils (sweet oil) that penetrate are the best. The wool
adjacent to the scabs should be cut away so as to allow the remedies to
get at the newly affected portions.

COMMON SCAB.
PgoROPTES COMMUNIS, Fiirst., var. OVIS.
Plates VII and VIII.

Common scab is caused by an insect known as the scab-mite or itch
insect— Psoroptes communis, Fiirst., var. ovis. This insect is much larger
than the Sarcoptes, which causes head scab, being visible to the unaided
eye. af
Disease.—Of all the diseases of sheep in this country, scab is the most
feared by the flockmaster. So insidious is its attack, so rapid its
course, so destructive its effects, and so difficult is it to exterminate’
that it has justly earned the distinction of being more injurious than
any other disease caused by external parasites. Scab alone, of the par-
asitic diseases, has become the subject of legislation in most countries,
and yet, if proper precautions were taken and a rational treatment fol-
lowed, this disease could soon be completely eradicated.

Karty symtoms.—Attention to the disease is first attracted by the in-
fected sheep scratching, biting, and rubbing themselves. The coats
of the animals look rough, taggy, and felted. The itching is always
57

most violent when the sheep have been heated by driving or warming
in a stable.

Pathology.—By separating the wool and examining a recently infected
spot, there can be seen some minute elevations, which differ from the
surrounding skin in being slightly whiter or yellower, and which have
been produced by the bites of the pests. The insects themselves can
be found among the hairs at but little distance from the bites. As time
passes and the insects multiply in numbers these elevations become
more and more numerous, and closer and closer together, until they
finally unite over a considerable extent. From the summit of each eleva-
tion or papule, a watery, serous fluid exudes and accumulates, which |
transforms them into vesicles and pustules, and which in drying cover
them over with a thin crust. Ina few days the whole surface is cov-
ered with a yellowish, greasy, scaly layer, under which the parasites
are hidden. As the disease ‘proceeds this layer gradually increases in
thickness by an increase of the serous exudate, and in circumference
by the extension of inflammation produced by the ever-multiplying par-
asites which live beneath it, forming scaly crusts. These crusts, in be-
ing torn out, mainly by the rubbing with which the sheep endeavors to
. allay its intense itching, carry with them the tags of the wool, the loss
of which is an early symptom of the disease. At a later period the
crusts are replaced by another set of thicker, firmer, adherent scabs,
which are still further enlarged by the outward migration of the para-
sites. As they abandon the center of the scabs these are again replaced
by a peeling off of the external layers of the skin, which gradually
heals, while the disease slowly progresses at the outside. The complete
‘eure is very slow, and the skin remains thick and folded for a long
time. In sheared sheep the skin becomes covered by a thick, dry
crust, like parchment, while beneath it remains much swollen.

Late symptoms and diagnosis. —tThe fleece of scabby sheep presents a
characteristic rough look. In places the wool is stuck together in
masses; in others it fails, while in others, which are apparently sound,
it can be easily plucked off. The rubbing and scratching indulged in
by the sheep not only tend to tear away the wool but increase the
irritation of the skin, which may become intensely inflamed and swollen
and finally end in a superficial death of the part. Unlike Sarcoptes,
the Psoroptes seeks the longest, thickest wool. It begins its attack aloug
the back and extends to the neck, flanks,and rump. The Psoroptes
are rarely found in the region of the chest and abdomen. They are
collected in masses on circumscribed stirfaces. The scabs they produce
constantly increase at their edges, and their number depends on the
number of places invaded. Owing to the closeness in which sheep con-
gregate and to their violent scratching the parasites become very gen-
erally scattered and finally the scabs may run together.

While few of the parasites are present in the older diseased parts, at
the edges of the scabs they can be found in swarms. They look like
58

little white points with a brownish extremity. If picked up by the
point of a knife or a sharp stick and placed on the hand they will be
seen to move. The six-legged young, the eight-legged adults, the
sexes, couples joined together, and the eggs of this interesting insect
can easily be identified by the aid of a low-power magnifying glass.

Prognosis.—The disease is favored in its advance by the seasons in
which the wool grows longest, aud in which the sheep are brought into
closer contact in sheds. Autumn and winter are the most favorable
for its spread and rapid advancement. In summer, and especially after
shearing in spring, the disease makes little, if any, headway until the
wool has grown to a considerable length. Age, temperament, state of
health, energy, and race of the animals, the length, fineness and abun-
dance of fleece, and the hygienic surroundings have much influence on
the advance, progress, and termination of the disease. The young, the
weak, the closely in-bred, the long coarse-wooled sheep, and those sub-
jected to bad climate, to unhealthy localities, to poorly constructed, illy-
ventilated sheds, are all more subject to the rapid advances of the
disease. On the other hand, healthy, well-fed, well-housed sheep may
withstand the ravages of the disease for months.

When left to itself scab causes severe disturbances of the functions
of the skin, and on account of the intense itching brings on fatigue,
through loss of rest and sleep. Marasmus and cachexia preceding,
death may come to weak, ill-nourished subjects in two or threemonths. |

The mortality due to scab varies much, depending on the season, gen-
eral health of the flock, food. shelter, and a variety of other factors. It is
most disastrous in autumn and winter among sheep poorly fed and housed,
and of weak constitutions. Many other diseases-may intervene and carry
off the weakened animals. The death-rate is not the only occasion of
loss, for whether the shepherd keeps his flocks for mutton or wool he
will find a loss in either, depending much on the severity of the dis-
ease. Ewes weakened by the disease will remain infertile, abort or pro-
duce but weak and feeble lambs, which will either die or scarcely be
worth the rearing. To this loss must be added the decreased value of
the wool obtained from the first shearing after a recovery from the at-
tack, due to the mixing of the ends of the old wool with those of the
new, known as the double-ended wool. This mixture lessens the value
for manufacturing purposes.

Source of contagion.—Remembéring that common scab is caused by
insects which the infested flocks are continually spreading broadcast
by dropping tags of wool by the wayside, by leaving them attached to
brush, by rubbing posts and fences, it is easy to realize that there are
many methods of transmitting the malady. Experiments with these
insects have shown that they can live at a moderate temperature on a
piece of scab from ten to twenty days; that they may live after being
subjected to intense cold; that they die more rapidly when they are in
contact with animal matter at freezing temperature, and that they die
59

Soon if they remain exposed to alternating hish and low temperatures.
These experiments show that the Psoroptes can live about the sheep
sheds, yards, corrals and fences during twelve or fifteen days, at least,
after they have separated from the sheep.

Although this species of parasite is but a variety of the Psoroptes
communis, of which the Psoroptes parasitic on horses is another variety,
the latter has not yet been made to grow on sheep experimentally. It
is not probable that either of the varieties parasitic on cattle or rabbits
would thrive on sheep. That is to say, so far as is now known, sheep are
infected with common scab from other sheep, and can not acquire it
from other animals. On the other hand, the ovine variety of Psoroptes
has not yet been found to growon other species of our domestic animals.

Differential diagnosis.—Psoroptic, or common scab, is different from
Sarcoptic or head scab, in that the former chooses to live where the fleece
is longest, and the latter where there is little or none at all—the one on
the back and sides, the other on the head and occasionally on the nether
parts; the one is almost invisible to the naked eye, and the other is
plainly seen, though small. The itch due to other parasites, such as
sheep ticks and sheep-lice, can be easily separated, because they are
large and can be found in the wool. Sheep are sometimes subject to
an inflammation of the sebaceous glands. In this, however, there will
be no parasites of any kind found.

Prognosis.—Scab, as has been said before, is one of the “aie dreaded
diseases of sheep. For the flockmaster who has but few sheep, say
fifty or a hundred, the task of treatment and eradication of the scab
from the flock is no easy affair; but for him who owns from five to
twenty thousand the difficulties to be met are enormously increased.
Though the disease may be easily treated as far as a single sheep is con-
cerned, still the treatment would only be palliative and would not as-
sure the flockmaster that the disease would not break out again.
Treatment, therefore, of a flock in which scab has appeared must be
applied to every individual exposed and to the corral and sheep-pens
in which they have been lodged, and is not only a serious time-consum-
ing affair, but a most expensive one.

Treatment.—This is of two kinds—preventive and curative. The
preventive treatment is undertaken before, during, and after the
curative. Indeed, if the flockmaster exercises proper care his flocks
will never require the curative treatment, for the disease always comes
from transference of the insect.

Préventive—An_ infected flock should be quarantined so that it
shall not transmit the disease to other flocks, and should be kept from
public highways where other flocks may pass, until it can be thoroughly
cleansed and cured. The sheds, yards, and corrals where they have
been kept should also be cleansed, so that they may not transmit the
disease. After treatment begins the sheep should be transferred to a
temporary uninfected yard, so that the old yard may be thoroughly
60

disinfected by carting away the soil to some safe spot, by washing all
the wood-work as high as a man’s head with a solution of boiling lye,*
and afterwards covering it with a coat of whitewash. All old pelts
which could harbor the insects should be burned. Every possible se-
creting place for the insects should be overhauled. After a thorough
cleansing the yards should be left vacant for three weeks.

After the dipping the sheep should be driven into fresh, clean yards,
and not into such as have not been sufficiently cleansed. If possible
they should be kept from infected pasture ranges for three weeks, by
which time all parasites which may have dropped from them may be
considered as dead. Sheep which have been dipped in any of the
tobacco preparations can be, so it is stated, driven on the ranges im-
mediately after dipping with impunity, as the tobacco odor keeps the
insects away. Any sheep which may have died on the range should
either be buried deeply or burned. In dipping extreme care should be
taken by all who handle sheep not to transfer the pests from animal to
animal. ,

Medicinal.-.-There are two methods of treating sheep for scab. The
one of rubbing poisonous ointments and oils into the fleece by the hand
is the oldest and least used. It is slow, tedious, and unreliable, and
has been superseded by better methods.

The other consists in immersing sheep in watery mixtures which will
kill the parasites. This method being cheaper, quicker, and more
effective, is the one in general use in this country. The formule used
and the methods of applying them vary in different portions of the coun-
try according to the needs of the sheep-owner.

In the East, tubs large enough to hold sufficient of the dip to com-
pletely immerse the sheep, and kettles or cauldrons of a capacity to
heat the required amount are used, but in the range country of the
West, where thousands of sheep are to be treated, especially made dip-
ping pens and tanks through which the sheep may be driven, and large
boilers made for the purpose, are used. Each method is adapted to the
needs of the respective localities. Although some dips are fairly effect-
ive when applied to sheep with their fleeces on, the dipping should, as
a rule, be preceded by shearing. This rule should be violated only on
account of season. If any of the flock are infected all should be sub-
jected to treatment, otherwise the disease will be carried along and
break out from time to time. The shearing should take place in a shed
where all the wool can be cared for, and either poisoned or destroyed,
or so safely stored that it could by no possibility scatter the insects.
Any treatment undertaken without being preceded by shearing can at
best be considered as pailiative.

The object of the treatment is to kill the parasites and their eggs.
The parasites are killed by the direct application of a poisonous dip.
The eggs have a thick shell which often resists the effect of the poison,

 

* Use 1 part of potash to 200 of water.
61

and the young parasite emerges in due time. They are then subjected.
to a second dip some six or ten days afterwards, at which time it is pre-
sumable that all the eggs have hatched and none of the young have be-
come adult. If the second dip is delayed much longer than twelve or
fourteen days, some of the newly hatched larvae may have become adult
and laid eggs, which may in turn hatch larve, and become new centers
of infection.

All dips, to be effective, contain some ingredients which are poisonous
to the parasite. This poisonous element may also, if used in too con-
centrated a solution, be poisonous to the sheep, but this is to be avoided
by using the dips in the exact proportions of the formula given and
maintaining these proportions throughout the treatment. In addition
to the poisonous element, a dip may contain other elements, as water to
dissolve and to dilute the poison; also such a substance as alum or soda
to combine with the poison, as arsenic, to make it more soluble; or it
may contain an alkali, as soda or potash, to soften the scabs when ap-
plied ; or it may contain substances which are empirically added because
they have been experimentally proven of service.

The chief poisons used in the dip are tobacco, arsenic, and carbolic
acid. Of these, tobacco is the favorite, because its use has not been
followed by the fatality that has in times past followed the use of
arsenic. Carbolic acid is too expensive to be used in large quantities,
but is an excellent ingredient when only a few sheep are to be dipped.

The addition of tar to these dips is excellent, as the tar water is not
only good for the wounds but serves an excellent purpose of driving
away the flies.

The quantity of dip required for each sheep is variously estimated at
from 1 quart to1 gallon. For small numbers of sheep, say fifty or one
hundred, the larger amount is necessary, but for large flocks, 1 quart
for shorn and 2 for unshorn sheep may be allowed. It is always best
to have more of the ingredients on hand than is necessary, so that they
may not be used up before the dipping is finished and thus delay the
business. To make the dip more effective the solution should be ad-
mfinistered quite hot. The most desirable temperature is from 100° to
110° Fah., which is a comfortable one for the sheep, whose internal
temperature is about 103°. The warmth enables the dip to penetrate
the oily wool better, makes the parasites livelier, and proves far more
efficient.

Instead of treating the scab by one application some authorities ad-
vise the use of a preliminary dip of alkaline water to soften the scabs,
or of oil or glycerine well rubbed in for thé same purpose. This is to be
followed in two or three days by a poisonous dip. Nearly all advise
that the scabs should be rubbed with a stiff brush while the sheep is
being dipped.

The Australian or Rutherford dip, which has been very successful in
the hands of large flockmasters, is as follows: Take of tobacco and
62

flowers of sulphur 1 pound each, to every 4 gallons of water to be used.
The tobacco should be steeped in a portion of the water two or three
successive times so as to extract alt of the juice. The leaves or stems
may be used; of the latter three times the weight is required as is
needed of the former; a press or wringer is convenient to squeeze out
all of the liquor from them. The sulphur should be mixed with some
of the tobacco water and stirred until it is of creamy consistency.
These ingredients should be added to the required amount of water.
During the dipping this mixture should he constantly stirred and a lit-
tle fresh water added from time to time to replace that lost by evapora-
tion.

This dip, to be more effective, should be heated to between 100° and
110° Fah. in summer, and 110° and 120° Fah. in winter, never being
allowed to fall under or exceed these limits. The sheep should remain
immersed in it from sixty to ninety seconds, and the bead should be
completely immersed at least once.

When sheep with heavy fleeces are dipped it will be found necessary
to separate the fleece with the hands, that the fluid may permeate better.
Eight or ten days after the first dipping the treatment should be re-
peated. Sometimes a third and more rarely a fourth dipping is neces-
sary. When the last two are required it is most often due. to care-
lessness in preparation, or a failure in the strength of the first dips.
Sometimes it may be necessitated by the rain having washed off the
first solution soon after dipping.

Australian sulphur and lime dip: Take of flowers of sulphur 100
pounds, of quicklime 150 pounds,’ water 100 gallons. Mix and stir
while boiling for ten minutes, until the mixture assumes a bright red
color, then add 8 gallons of water. Hold the sheep in the mixture until
the scabs are thoroughly soaked. Immerse tlie head at least once. Use
the dip at 100 to 110° Fah. Dip twice at an interval of two weeks.

In the American Merino, 1887, Stephen Powers gives an excellent
description of sheep-dipping on a large scale, and the following recipes
in use in various sections of the United States:

Texas and New Mexico: Thirty pounds of tobacco, 7 pounds of sulphur, 3 pounds
of concentrated lye, dissolved in 100 gallons of water.

Nevada: sulphur, 10 pounds; lime, 20 pounds; water, 60 gallons.

California: Sulphur, 4 pounds; lime, 1 pound; water, enough to make 4 gallons.

Kansas: Sulphur, 22 pounds; lime, 7 pounds; water, 100 gallons.

Sulphur and lime is probably the cheapest recipe, but the lime is apt to injure the
staple; still this recipe appears to prevail over all others in the scab-infested
regions. Probably tobacco and sulphur form the best combination known for the
treatment of scab. To every hundred gallons of water there should be used 35 pounds
of good strong tobacco (if stems or other inferior parts are used there should be
more), and 10 pounds of flowers of sulphur. This preparation used at a temperature
of 120° Fah., will kill all acari ticks and lice, and leave the wool in a healthy con-
dition. To insure thorough work apply a second time in ten days or two weeks.
63

Walz’s dip, one of the oldest recipes, is as follows: Take of frsatk
slaked lime 4 parts, carbonate of potash 5 parts, mix and boil in barn-
yard water; add animal oil 6 parts, tar 3 parts; dilute with barn-yard
lees 200 parts, water 800 parts. ‘To-day this recipe is more curious than
useful; one of the ingredients is not on the Americau market, and an-
other is offensive. Veterinarian Clok, in his Diseases of Sheep, 1861,
reports this mixture as being too weak for old cases, and recommends
the following modification: Take of freshly-burned slaked lime 6
pounds, add potash 6 pounds, and water 10 quarts; boil an hour, stir-
ring occasionally. Add pine-oil 8 pounds, and tar 2 quarts, stirring the
mixture thoroughly. Make an infusion of 20 pounds tobacco in 130
quarts of water; add the lye already made and stir. This quantity suf-
fices for one hundred sheep. Apply by immersing the sheep, separat-
ing the wool and breaking the scabs. Repeat in eight or ten days.

Law’s recipe (Farmers’ Veterinary Adviser) is a very good one: Take
of tobacco 16 pounds, oil of tar 3 pints, soda ash 20 pounds, soft soap 4
pounds, water 50 gallons. This quantity suffices for fifty sheep. The
tobacco should be steeped; afterward the other ingredients should be
added at 70° Fah.

Zundel’s dip is available, but Dr. Kaiser (Iuhrverfahren bet der Schaf-
réude, 1883) reports that it is too weak in cases of long standing. It is
said to leave the wool clear and white after using. For every one hun-
dred sheep take crude carbolic acid 3 pounds, caustic lime 2 pounds, pot-
ash 6 pounds, black soap 6 pounds, and water 70 gallons; mix and boil.
Dr. Kaiser has obtained excellent results from a modification of this
recipe. Take of tobacco 5 kilograms (133 pounds), infuse it in 250 liters
or 66 gallons water; dissolve in it 3 kilograms (8 pounds) soda, add 14
kilograms (4 pounds) freshly burned and slaked lime. Dilute 3 kilo-
grams (8 pounds) black soap (soft soap will do) with hot tobacco broth
and add it to the rest; then add 14 kilograms (4 pounds) crude carbolic
acid, which contains at least 50 per cent. of the pure acid. Mix. This
quantity is sufficient for one hundred sheep.

Gerlach’s dips, which are administered at two different times for a
single treatment, are cheap, but owing to the time and labor to be ex-
perded in performing an operation twice which in other instances is
done but once, is much more costly than those which require but one
application.

Take of potash 2 parts, burnt lime 1 part, water 50 parts. Mix. Use
this dip for softening scabs. Follow it in two or three days by the fol-
lowing: Make an infusion of tobaeco 34 pounds in 66 gallons water, by
slowly steeping the tobacco in a portion of water and finally adding it
to the remainder. Repeat the dip in from six to ten days.

Roloff’s dip, for a mixture sufficient for one hundred sheep, is: Take
7.5 kilograms (20 pounds) of tobacco, steep it with 250 liters (66 gal-
lons) water for half an hour, heat it to 30° R. (95° Fah.) and add 1
kilogram (24 pounds) each of pure carbolic acid and of potash.’
64

A cheaper and fully as effective dip of similar formula is the follow-
ing: Mix an infusion of 15 pounds tobacco with 1 kilogram (25 pounds)
carbolic acid and 5 kilograms (134 pounds) wood tar, pour it into 250
pounds (66 gallons) water at 40° R. (125° Fah.), in which 3 pounds
’ soda has been dissolved. Use it at a temperature of 80° or 90° Fah.,
and repeat in six or seven days.

There are three arsenical dips favoréd by European authorities, the
jast of which might be used while exercising proper care and precau-
tion. The solution should always be kept as dilute as the formula calls
for. The sheep should not be allowed to drain on the grass, but should
be kept up until nearly dry, and the laborers who dip should grease
their arms with linseed-oil before beginning work.

Tessier’s dip, the oldest, was proposed in 1810. To make a mixture
for one hundred sheep, take arsenious acid 3 pounds, sulphate of iron
20 pounds, and water 190 pounds; boil. .

Tessier’s dip causes a discoloration of the wool, which can be removed
by washing with soap, but it is on this account more or less objectiona-
ble, and to overcome this objection Clément has modified it as follows:
Arsenious acid, 1 part; sulphate of zine, 5 parts; water, 100 parts.
The water is put over the fire, the medicinal substances added, and it is
allowed to boil for eight or ten minutes. After the temperature has
fallen to the proper degree it is ready for use. The sheep is entirely
submerged in the liquid, with the exception of the head, the udder of
ewes suckling their young having been previously covered with some
fatty substance to prevent the action of the astringent on the skin and
on the secretion of milk.

Matthews dip: Take arsenious acid 1 part, alum 10, and water 100
parts.

Scheurle and Kehm’s dip: Take arsenic 1 part, alum 12, and water
200 parts. This latter is weaker than the former, and therefore safer.
Moreover, it is claimed to be as effective.

The sheep dips that are put upon the market are objectionable for three
reasons: First, their formulas are not given; second, the preparation
may be valueless, or if not valueless of insufficient strength; and third,
the preparation may cost more than it is actually worth. Should the
dip be put up by reliable houses, and have their formulas printed on
the outside of the package, the prepared article might prove better
compounded and absolutely cheaper than the flockmaster could pre-
pare it.

Police sanitation.—It is not sufficient that the flockmaster thoroughly
cures his flock, disinfects his sheds and quarantines his place. Another
duty awaits him, and that is a public one. All flock-owners should
unite and assist the State in improving and carrying out its sanitary
laws. Nearly all States have laws regarding the suppressing and
quarantining of sheep infected with scab, but they seem to lack in
stringency and are therefore inadequate. Laws compelling strict quar-
65

antine and public supervision of the treatment, at the expense of the
owner, even though it is undertaken by the State, are demanded for
the complete eradication of the disease. With such laws no one could
long harbor on his premises a disease which constantly threatens the
flocks of his neighbors with destruction and their owners with financial
ruin.

FOOT SCAB.
CHORIOPTES COMMUNIS, Verheyen, var. OVIS.

This variety of scab, which is due to Chorioptes communis, Verbeyen,
var, ovis, is of rare occurrence. ‘It has been noticed and studied in Ger-
many by Ziirn. : ,

The seat of this disease is in the feet and limbs. The disease pro-
gresses very slowly from the feet, and little by little invades the upper
parts of the limbs and adjoining parts. Itis not readily communicable
to other sheep and spreads slowly.

In the beginning this variety of scab is characterized by the redden-
ing, followed by au abundant scaling of the skin, and later by yellowish
white crusts. The animals stamp, scratch, and bite the parts, showing
anintense itching. As the disease progresses the crusts become thicker;
cracks may form in the folds of the pastern and the limbs become quite
unsightly. The parasites swarm beneath the crusts, and when found
form a certain symptom of the character of the disease.

Foot-scab is not a serious malady, as it readily yields to treatment
and is of slow extension. Any of the remedies proposed for the treat-
ment of common scab may be used with good effect.

23038 A P-——5
PSOROPTES COMMUNIS Fiirst., var. OVIS.

PuaTE VII.

Fig. 1. Adult male, dorsal view: a, head; b b, legs; ¢¢, suckers.
Fig. 2. Adult male, ventral view.

Fig. 3. Adult feinale, dorsal view.

Fig. 4. Adult female, ventral view.

Novre.—Figs 1 to 4, Plate VII, and Figs. 1 to 3, Plate VIII, are cqually magnified.
PLATE VII

 

A.Hoen & Co. Lith, Baltimore,

Haines, det. PSOROPTES COMMUNIS, Var OVIS,
(The Common Scab-Mite.)
Fig.
Fig.
Fig.
Fig.
Fig.

Fig.

Fig.

68

PSOROPTES COMMUNIS Ftirst., var. OVIS.

PuatTe VIII.

Young female before moulting for the last time.

. Egg drawn from a specimen which was inside an adult female.
. Young six-footed larva.
. a, open, and b, closed sucker of Psoroptes from ears of rabbit; c, the rod which

connects the membrane on the end with the muscles which close the
sucker.

. Two views of the mandibles. The lateral spurs, @, a, point outward

(Megnin).

. Head and anterior limb enlarged; ventral view: a, mandibles; b, antennx;

c, maxilla; d, membrane joining the antenne; e, e, e, joints of the limb;
f, the claw; g, the ambulacrum or sucker.

. Male and female of Psoroptes communis var. equi (Megnin).
PLATE VIII

 

A.Hoen & Co. bith. Baltimore,

Haines, del.

PSOROPTES COMMUNIS, Var OVIS,
(The Common Scab-Mite.)
THE PENTASTOMA.

LINGUATULA TZNIOIDES, Rud.
See Plate XVII, figs. 1-6.

Linguatula tenioides is also known under the names Linguatula rhi-
naria, Pilger, and Pentastoma tenioides, Rud.

In describing this parasite, Neumanu’s excellent description in Traité
des Maladies Parasitaires, page 491, has been taken as a guide. The
species is probably present in this country, as in two instances the larval
form known as Pentastoma denticulatum has been found. Thelarve were
found by Dr. F. L. Kilborne, of this Bureau, in a rabbit, some time in
the summer of 1887, and once by myself in another rabbit in 1888.

This curious parasite is classed among the Arachnids, being more
closely related to the spider and mite family than to any other. The
order Linguatulide, to which they belong, is thus defined:

Endoparasitic arachnids with elongate, vermiform, annulate body. Mouth want-
ing jaws in the adult state, and surrounded by two pairs of hooks representing rudi-
mentary feet. No heart. Respiration cutaneous. In it are two genera: (1) Lingua-
tula, Frohlich, which has the body depressed with dorsal face rounded and with the
borders crenulated. The cavity of the body forms diverticula in the lateral parts of
the rings. (2) Pentastoma, Rud., which hasa cylindrical body and the cavity of the
body continuous. It is not represented in our domestic animals, unless it be a lar-
val form found once in the peritoneal cavity of a dog. ‘

Description.—The species met with in the domesticated animals has

the following characters:

Body white, lanceolate, very elongate, worm-like, depressed dorso-ventrally with
the ventral face nearly plane and the dorsal face convex. Anterior extremity
rounded, large; posterior extremity attenuated. Cephalo-thorax short, solidified in
all its width to the abdomen, from which it is scarcely distinct, and which forms by
far the larger part of the body. Integument showing about ninety rings, larger in
their middle; these make the borders of the body crenulated. Hooks acute, re-
- curved, twice-jointed, the basal joint attenuated in its deep part. These hooks, each
retractile in a pocket, are moved by muscular bundles which act in opposite direc-
tions. Mouth sub-quadrangular, rounded at the angles; digestive tube simple, rec-
tilinear; anus terminal. Male, white ; length from 18 to 20™™; width, in front, 3™™;
behind, 0.5™™, provided with saccular testicles which fill the body cavity even to ‘ise
anterior fourth. Female, whitish grey, often rendered brown by the eggs along the
median line where the integument is thin and semi-transparent; length from 8 to
10°; width, in front, from 8 to 10™™, and behind, 2™™. Eggsovoid; length, 0.09™™;

width, 0.072".
Life history.—The female Linguatula tenioides lays its eggs in the
nasal cavities of the dog. These are scattered on the ground and grass
69
79

where they lie until eaten by some herbivorous animal. The shell is
then’ dissolved from arouhd the embryo, and it bores through the walls
of the stomach or intestine into the mesenteric gland, liver, or lung,
where it encysts itself. In its first stage of active migration the larva
resembles the Acari (Plate XVII, Fig. 4). It has an ovoid body, flat-
tened on the ventral face, rounded on the dorsal. Its posterior extrem-
ity is narrowed and dentate. It is furnished with two pairs of articula-
ted, two-clawed feet, and at its anterior end by a perforating apparatus
formed of a median stylet and two re-curved hooks. Its length is
0.18"; its width 0.06™.

Having arrived at the mesenteric glands, the liver, or the lungs, as the
case may be, the embryo loses its feet and is transformed into an im-
movable pupa (Fig. 5), without segments, hooks, or hairs, measuring
0.250 to 0.800" long, and 0.180" in width.

It emerges from this cyst transformed into another larva by a series of successive
moults (see Fig.'6). The body is elongate, Jarger forward, and is divided into eighty
to ninety rings bordered behind by a series of fine spines. The digestive tube is
large, the month is elliptical, and surrounded with four characteristic hooks and with
accessory hooks. ‘The larva isagamic, its genital organs being rudimentary and rep-
resented only by a little granular mass in the posterior part of the body. ‘Towards
the sixth or seventb month the larva is completely developed, measures 6 to 8™™ long,
and is in the stage called Linguatula denticulata, ;

These larve having escaped from the cyst, fall into the serous cavities and remain
there for some time. They eventually escape, but the precise method is unknown.
Next they are seen in the nasal cavities of dogs. Exceptionally, so it is said, they
are found in the nasal cavities of sheep and cattle, into which they have wandered.
These larve can acquire their full development only in the respiratory passages. Once
installed in the nasal cavities they develop into egg-bearing adults. The males wan-
der and can be found at various points of the cavities, but the females are more
sedentary, and are never found in the ethmoidal cavities. After the death of the
host they may travel into the pharynx and larynx. They exceptionally introduce
themselves into the frontal sinuses. They are generally found at the bottom of the -
nasal chamber. .

As the adult stage is not usually found in sheep, and as its occurrence
is problematical in this country, the disease it causes will not be con-
sidered in this volume.

Disease.—The young state, Linguatula denticulata, found in cysts
within the glands, ete., are said to be particularly frequent in sheep in
Europe. Sheep in which the parasite affects the mesenteric glands are
generally less fat; their flesh is paler, and they are apparently predis-
posed to anwmia. These glands show no evidences of the parasite at
first, but later they grow browner, smaller, and are crossed by galleries
filled with larvae. These cavities are separate at first, but finally com-
municate; the substance of the gland is destroyed and transformed into
a brown tumor, in the middle of which are the Zinguatule. From these
the parasites often escape through openings with irregular borders; at
other times the surface is covered by dark, irregular spots, fibrinous de-
posits, and false membranes, which indicate a recent departure or a de-
71

struction of the embryos. At last the tissue is found thickened, indu-
rated, and offers here and there tuberculoid grains formed from the old
nests of Linguatule. These altered glands are destroyed and are of.no
further use in nutrition. The larve create further troubles in their mi-

- grations, but so little is known about these parasites that little can be
said.

There is no treatment. Prevention is also difficult. If it should be
learned that we have these parasites here in considerable numbers the
best remedy would be to remove the dogs, which are certainly the cause
of large numbers being scattered in Europe.
IMMATURE TAPE-WORMS—BLADDER-WORMS.

Plates IX, X, and XI.

Besides the adult tape-worms found in the intestines of sheep, there
have been four other species described which infest various portions of
these animals in their immature stages. These species are Tenia mar-
ginata, Batsch, T. coenurus, Kiich., T. echinococcus, v. Siebold, and T.
tenella, Cobbold. The forms found in sheep were first described as
Cysticerci, and have since been known as Cysticercus tenwicollis, Coenurus
cerebralis, Echinococcus and Cysticercus ovis, respectively. .

All these species resemble each other in their anatomical structure,
their growth, and their life history. They differ in minute structure, in
invading different portions of the sheep, and in the effects they produce
on the animal.

Tenia marginata is more common in the United States, and T. coenurus
next. Neither of the other two species have been found in sheep in this
country.

TANIA MARGINATA, Batsch.
Plate IX.

Tenia marginata occurs in sheep as a little semi-transparent bladder
filled with liquid, varying from a very minute size to a bag an inch or
more in diameter, but usually having a diameter of a half or three-
quarters of an inch.

Occurrence.—This tcenia, in its eysticercal stage, is usually found be-
tween the layers of the serous membrane which form the omentum, or
‘‘caul” of the abdominal cavity. It may be found in the liver, espe-
cially within a week or two after the infection of the sheep by it. A very
common place to find it is between the folds of serous membrane which
suspends the intestine in the pelvic cavity. When one of these little
fiuid-sacs are found it may be cué out, with the surrounding tissue for
examination. Afterwards great care should be taken in dissecting the
serous tissue, which forms an outer sac, so that the cysticercus within
shall not be cut, its conteats allowed to escape and its walls to collapse.

Description of cystic stage.—The smaller bladders are apparently com-
posed of a semi translucent whitish membrane, at one end of which may
be seen a whitish thickening. As the bladders grow the walls become
slightly thicker and the spot at the end becomes much larger and pro-
jects in the form of a knob.

72
73

When the animal is placed in a saucer of lukewarm water immedi-
ately after its removal from the slaughtered sheep and examined, it
can, by the aid of a low-power lens, be seen to possess considerable
peristaltic movement. This movement is produced by bundles of
muscles lying at right angles to each other, which may be seen appear-

ing as a faint striation on the surface.

The little knob end of the bag is its essential part, and contains what
is to develop into the future tenia. Sometimes the animal will extend
this knob into a cone, and finally thrust out of its center the very tip
of the cone. By careful handling this so-called head end may be
squeezed out by the fingers. The tip, when examined by a magnifying
glass, can be seen to possess four cup-like spots, with a little glittering
circlet of hooks between them at the very apex of the cone.

Life historya—When these cysts have attained their hooks and cups
in a well developed condition, they are ready for transplanting into
another animal or host. The cysticercus completes its development in
about eight weeks. It may live a long time after this, and its cyst

’ enlarge, but the modifications it may undergo are unessential. The
host within which the cysts or cysticerci generally develop is the dog.
They may, however, also develop in other carnivora, such as the wolf
or coyote.

Their emigration is a passiveone. They remain encysted where they
are found until the sheep is slaughtered and the dogs eat the offal, or
until the sheep is killed by a dog or wolf and its liver is torn from its
place and devoured, together with any of the cysticerci which may be
attached. Having gotten into the intestines of the host the parasite
completes its development, becomes adult, and finally produces young,
which pass from the host along with the ejecta of the intestines.

The young at this stage are egg-like. They are very small and
hardly visible to the naked eye. When viewed with a glass they are
seen to be a minute, jelly-like mass, furnished with six hooks and sur-
rounded by at Jeast three membranes. The outer is thin and filled with
fluid; the inner two more closely surround the embryo, and confine be-
igen them an oily material which serves to protect it when exposed to
the atmosphere.

After passing to the ground these embryos in some way, possibly by
adhering to food or by floating in drinking water, make their way into
the sheep. When they arrive in the abomasum, or fourth stomach, it
is supposed that the gastric juice digests the membraues surrounding
the embryos and they then begin their active wandering. At this stage
they penetrate the walls of the fourth stomach and make their way
between the walis of serous membranes to the place where they finally
find lodgment. This active migration must often be couverted into a
passive one after the embryo has made its way through the mucous
coat of the stomach, for when the embryos have been fed in large num-
bers to tie sheep in the course of the experiments of different investi-
74

gators the liver has been found to be filled with multitudes of them.
One investigator has found them in the minute branchlets of the portal
vein, which conducts the blood from the stomach and intestines to the
liver. Now, in order to appear in the liver and in the portal vein in
such numbers the embryo must make its way into the little branches or
capillaries which collect the blood at the stomach, and then be washed
by the blood current into the liver. When they become lodged in the
liver they again migrate actively and tunnel through the mass of the
liver in alldirectious. The little channels are made slowly. They begin
as a minute point, and become gradually larger as the parasite increases
in size and changes its position. About the ninth day after the embryos
have been swallowed some of the parasites may be as large as a flax-
seed; most of them will be smaller. They will then be little oval water-
bags, with a whitish thickening at the end.

Some of the parasites seem to pass the entire length of the intestine
before they penetrate the walls; but when they reach the rectum they
pass through, and, becoming loner) between the layers of serous mem-
brane, develop there. This probably accounts for the presence of the
considerable numbers which are found in the pelvis.

The destination at which these parasites arrive has its influence oD |
their development. When they have migrated to a point between
serous tissnes which may be easily spread apart, and offer little resist-
ance to the growing parasite, a certain proportion of them seem to
thrive and arrive at a stage in which they may continue development
by the proper exchange of hosts. If this exchange is not effected the
parasite may remain unharmed for a long time while awaiting this
opportunity. Should they die from any cause a slow change in the
appearance of the parasite is noticed. The fluid it contains becomes
milky and limy. The serous sac surrounding it becomes thicker; finally
such chaiges have occurred that in place of a soft sac a round, hard
sphere of lime covered by a thick membrane may be found. The re-
mains of the parasite may still be seen by careful dissection between
the cover and the limy deposit.

But when, on the other hand, they arrive at the liver they seem to
have reached a place of destruction; for if they do not kill the invaded
host within two weeks, a period long before they could coutinue their

_ life in another host, thesame degenerative processes seem to affect them,
in their earlier stages, which destroy the older individuals in other or-
gansofthebody. This seems in part due tothe pressure which the liver
cells and capsule exert upon them. These statements seem substanti-
ated by the presence of either scars or calcareous nodules in the liver
aud of no large cysticerci, except where the loose serous membrane may
have permitted their growth.

These parasites have occasionally been observed in other parts of the
system than those mentioned, as in the lungs, heart, and muscles.

Disease—The harm that Tenia marginata does in its young stage
depends much on the degree of infection. In experiments animals have
15

been killed in from nine to twelve days after feeding. In such cases
the sheep uswally die of hemorrhage from the liver and peritonitis. This
is caused by the perforations of the serous covering of the liver due to
the parasites. These experiments show that the parasite is injurious to
Sheep. The presence of a few well-advanced cysticerci in nearly all of
our sheep also shows that though the parasite may be injurious in its
young stages, the sheep rarely succumbs to them in their period of inva-
sion. After a period of about twoweeks the sheep seem to have no dis-
comfort from them. a

Sheep may be invaded by the tenia at almost any time of the vear.
The winter season, when the embryos which have been scattered by the
dogs become frozen, seems to be less favorable. If the dogs have
access to the sheep-pens even this season will not delay the infection.
Lambsand yearlings appear to be most subject. Three months’ lambs
are the youngest in which the cysticercit have been found. Experi-
ments in attempting to produce the cysts in old sheep by feeding gen-
erally fail, Young sheep furnish the best specimens, while in five or
six year old sheep the cysticercit seem to have degenerated into calea-
reous nodules,

‘The adult tenia live in dogs. Soon after the cyst is swallowed the -
tissue is digested from it, and the large, watery bag, which has prob-
ably already lost its fluid in the mastication of: the food, disappears.
The head remains, and passing from the stomach into the intestine at-
taches itself by its hooks and cups, which serve as suckers. Here the
parasite, bathed in the intestinal fluids which nourish it, proceeds with
its development. In a day or two it lengthens and begins to show

— cross lines, which indicate the points where the division into segments
is to occur. Later the segments appear and the worm gradually ma-
tures the organs of reproduction in them. After ten or twelve weeks
have passed, the parasite begins to lose its end segments, which have
fully developed embryo in them, and are ready for the infection of sheep.

Description.—Tenia marginata, Batsch, or Tenia cysticerci tenuicollis
Kiich., is the largest of the tenia infesting dogs. It is usually, when
mature, about a yard long. Large specimens may be stretched, when
fresh, until they are 24 yards long. The greater number of specimens
are, when contracted, under a yard long. The width of the worms also
depends on their degree of contraction, the more contracted specimens
being the widest. The average of relaxed specimens is about two-fifths
of an inch. The same specimens, when alive, might contract so much
as to measure three-fourths of an inch. The widtb of the worm gradu-
ally widens from its bead for four-fifths of its length, and then contracts
slightly totheend. This species is moderately thick, measuring a little
over a twenty-fifth of an inch where thickest. When first taken its ap-
pearance is white and opaque, but when kept in water it becomes par-
tially transparent. It then resembles a whitened, pliable band of geia-
tine. At its small end is the so-called head, which is separated from the
76

body by scarcely any constricted neck. The head is quadrangular, is
about one-twenty-fifth of an inch in diameter, and has a circlet of from
thirty-two to forty hooks at its apex, and four moderate sized suckers.
The specimen figured contained twenty-eight. These hooks and suck-
ers serve to anchor the parasite to the intestinal walls. The neck is
short, and at a little distance from the head shows the division into seg-
ments which become plainer and plainer towards the end of the body.
The segments are at first very short and broad, but gradually lengthen-
ing become square where the animal is widest. when relaxed, and about
twice as long as broad at the end. The terminal segments measure
about one-fourth of an inch wide and one-halfinch long. There is no ali-
mentary tract, the office of absorption of food being filled by the skin.
Motion is effected by muscular bundles situated beneath the skin, which
give a variety of vermicular movements. <A primitive nervous organi-
zation has been described. The entire length of the worm is traversed
by two canals connected in each joint by a cross system. This system
is said to serve as an excretory apparatus. It has been called a vascular
system. Each adult segment contains a complete hermaphroditie gen-
erative apparatus. They begin to appearin the first third of the animal
and gradually mature toward the last segment. At about the middle
the eggs become fertilized and develop until the end. The terminal seg-
ments when ripe separate and pass away. In this way the segments,
which were once near the head, become central and finally terminal,
growing adult, maturing their embryo, and passing away in turn. The
embryonic shells are 0.036™™, about one-seven-hundredths of an inch
thick. The embryo is six-hooked. These worms mature and liberate
segments in the dog in about ten or twelve weeks after the cysticercus
has been swallowed.

Occurrence.—The. mar ginate tape-worm is found at about the middle
of the small intestine, therein differing from Tenia serrata, T. coenurus,.
and 7. cucumerina, which live nearer the end of the small intestine.
They may be found in dogs of any age. Shepherd or collies, hounds,
and slaughter-house dogs are most liable to be infected. City dogs,
which have but little opportunity of being infected, rarely contain the
parasite. /

Disease.-—The harm that the parasite does the dog seems to be in-
considerable. Were it not that the cysticercal stage does harm to sheep,
it might well pass unnoticed by the flock master. The ease with which
one can rid his dogs of the parasite seems to place the destruction of
the species in his hands. For Tenia marginata alone the administra-
tion of an effective tenicide every two months would be sufficient;
but as ZT. cenurus develops in three or four weeks, it would be best to
treat for both at once and dose the dogs more frequently.

Diagnosis. —Every sheep-owner should proceed to dose his dogs with
worm medicine, whether they are known to have tape-worms or not.
The diagnosis of tape-worms in dogs is difficult, those having many
often showing no symptoms. Sometimes they may be suspected from
TT

the leanness of the animals or from the little white segments they pass.
Such are the benefits arising from thorough medication that the time
and expense given is well laid ont.

Medical treatment.—The method of treatment consists in tying the
dog and withholding its supper, not water, over night. Some admin-
ister a physic at this time. The special worm medicine chosen should
be given on the next morning, and followed two hours later by a dose
of physic. The worms, if the treatment has been effective, should be
voided inside of twelve or eighteen hours. The dog should be fed
sparingly for a day or two preceding the operation. The preparatory
physic may be omitted. The dog may be fed at noon on milk or meat.
He should not be loosened until the following day. The excreta passed
should be burned or buried in some safe place. The method of admin-
istering the medicine is as follows: A man of whom the dog is not
- afraid should place himself in a corner aud back the dog between his
legs. He should then grasp the muzzle gently but firmly in one hand;
with the other hand should pull out the loose cheek at the corner of the
mouth. Into the pocket thus formed an assistant can put the medicine,
a dessert-spoonful at a time. The lips should then be held close, and
the dog will usually move his tongue sufficiently to swallow the dose.
Should he refuse, his nostrils may be closed for a second or two until
he gasps for breath, when the medicine will be swallowed. If any con-
siderable quantity is to be given the operation should not be hurried,
and should be persevered in with care and patience. Soine dogs will
eat their medicine mixed with milk or soup, while others are very fas-
tidious.

Areca nut has proven itself the best tenicide for dogs. The freshly
ground powder is the best. The rule for measuring the dose is to allow
two grains of the powder to each pound of the dog’s weight. The powder
is thoroughly stirred with soup or milk. If refused, another dose may
be prepared by mixing it with butter or molasses until the mass is quite
soft, and administered by hand. Follow the medicine in two hours by
a table-spoonful of castor-oil for a moderate sized dog. The oil can be ©
given alone or well shaken and mixed with three times the quantity of
milk,

If areca nut is not available, a dose consisting of a tea-spoonful of tur-
pentine and two table-spoonfuls of castor-oil, thoroughly mixed with a
coffee-cup full of milk, may be substituted. This dose is one for an
average-sized farm dog. The final physic is not given in thiscase. A
-2-ounce dose of castor-oil will bring away portions of the tape-worms,
and sometimes the heads, without the aid of other worm medicine.

Finlay Dun recommends the following prescription: Take 20 drops
of the oil of nale-shieldfern, 30 of the oil of turpentine, and 60 of ether.
Beat them together with one egg and give to the dog in soup.

Ziirn advises the use of about 4 drams of freshly powdered areca nut
for a very large sized dog, 24 for a medium sized, and 1 dram for a very
18

“pew

small dog. The powder is to be rubbed up with butter. Follow in two
hours by a table-spoonful of castor-oil.

Dr. Hagen advises treatment of all sheep dogs each spring and fall,
thereby claiming an increased immunity for the sheep from the cysticerci.
He recommends the following: Take of the oxide of copper 80 grains,

_of powdered chalk and Armeuian bolus 40 grains each ; of water sufti-
cient to mix the ingredients into an adberent mass; divide into one
hundred pills; administer one three times daily for ten days by crush-
ing them in a piece of meat or bread and butter.

In addition to other remedies R6ll prescribes the following: (Each
dose is for large dogs. For smaller ones proportionately less ought to
be given.) (1) Extract of malefern and the powder of male-fern, 2
drams each. (2) A decoction of 24 ounces of pomegranate-root bark in

~ water, reduced to 6 fluid ounces, and add 1 dram of extract of male-fern,
to be given in two doses an hour apart. (3) From one-half to 1 vunce
kousso formed into pills with honey or molasses, and a little meal. (4)
From i4 to 24 drams of Kamala stirred with houey or water, and given
in two doses inside of an hour. He advises a prelimivary preparation
by feeding the dogs sparingly for two or three days previous on salted
food, and the administration of castor-oil the eveniug before. The rem-
edies proposed are to be mixed with some material to make them fairly
acceptable to the patients. With the exception of kamala, which acts
as a cathartic, all should be followed in two hours by castor-oil.

After any treatment the patients should be fed with some liquid diet
on the first day. After this they may receive any wholesome food.

The necessity of repeating a treatment depends entirely on the
efficacy of the first, and the care exercised in preventing a re-infection.
If the treatment has been successful in removing the worms, heads and
all, of course no further treatment will be required. If only portions
have been removed, then another desing is necessary. For tenia mar-
ginata another treatment need not occur under eight weeks, for the
tape-worm is harmless as far as sheep are concerned up to that period,
for, as far as is known, the worm will not throw off segments before that
time. For 7. cenurus the treatment should be repeated in about two
weeks,

Preventive treatment.—The great resource of the flockmaster lies in
prevention. In this he has nearly absolute control over the health of
his sheep, in so far as Tenia marginata and T. cenurus are concerned.
As the dogs can only get these tania from eating viscera of the sheep,
all the viscera of slaughtered or dead sheep should be withheld from
them, and either buried, burned, or rendered. .

Police sanitation.—Sheep-killiug dogs should be destroyed. Each
owner should keep his dogs at home, so that all strange dogs may be
killed in order to prevent them from harming sheep and scattering the
tenia eggs far and wide over the pastures and in the drinking places.
Dog laws ought to be made sufficiently stringent and adequate for the
protection of sheep.
Fig.

Fig.

Fig.
Fig.
Fig.

1.

80

TANIA MARGINATA, Batsch.

PuLaTE IX.

Adult tenia, natural size: a, head (the constricted part following is the
neck); b, point at which the reproductive organs begin to develop ; © & ¢,
adult segments either separated or about to separate.

. Head: a, the crown of twenty-eight hooks; 6, b, the suckers or bothria; ¢,

the neck, which is transversely wrinkled, but not segmented.

. Crown of hooks enlarged: a, a, large hooks; b, b, alternating small hooks.
. Form of single hook.
. Bladder or Cysticercus tenuicollis (taken from the omentum or caul of a sheep),

which produces the tenia when fed to a dog: a, the head; b, the bladdery
portion filled with fluid.

. Head of Fig. 5, enlarged, shows the opening from which the true head may

be evaginated.

. Head of the cystic worm, evaginated, shows the suckers and crown of hooks.
. Segment from near d Fig. 1 shows the branching uterus which is filled with

ova,
PLATE IX

 

 

ieee:

eRe

je foros es

POET EEE PE Ere

  

ya oe a ae ae

 

 

 

EET ET |

 

  

 

 

A Moor & Co, Lith. Baltimore,

TAENIA MARGINATA,
(The Margined Tape-Worm of Dogs.)

Geo. Marx, del.
82

TAINIA MARGINATA, Batsch.
PLATE X.

Fig. 1. Portion of a liver from alamb which died nine days after feeding with the
embryo of Tenia marginata, drawn from an alcoholic specimen; natural
size. The surface is seen covered withshort ridges, which run in all direc-
tions, and are more numerous toward the thin edge of the liver.

g. 2. Cross-section taken at aa, in Fig. 1, shows the round cross-sections of the
burrows made by the young embryos; also oblique and longitudinal sec-
tions of them. The lower edge is rough and terminates in liver substance,
not in the capsule.

Fig. 3. Young embryo or cysticerci: a, natural size; b, x6.

Fig. 4. Embryo in the state in which they are fed to the lamb to produce the disease.

(Leuckart), x550,

=
a
PLATE X

 

A Hoen & Cou, Lithocaustic Baltimore

Haines, del.

LIVER OF LAMB INVADED BY YOUNG TAENIA MARGINATA.
GID OR STAGGERS.

TANIA CaeNuRUS, Kiich.
Plate XI, Figs. 1 to 4,

The disease which is popularly known as gid, sturdy, staggers, or
turnsick in sheep, is caused by the presence of a parasite living in the
brain. This parasite is closely related to Tenia marginata. It lives in
about the same way, but differs from it in detail. It is known as 7.
cenurus in its adult state, and as Cwnurus cerebralis in its cystic state—
the stage in which itinfests sheep.

Method of infection.—Sheep become infected with this dangerous para-
site while pasturing or drinking where dogs have scattered the eges in
their wanderings through the country. In the West the eggs may also
be scattered by the wolves, coyotes, and foxes, which may harbor the
adult parasite.

Life history.—The eggs of Tenia cenurus, after being taken with the
food or drink, are hatched within the stomach of the sheep and make
their way through its walls. They then migrate either actively, by
forcing their way through the connective tissues, or passively, as is
generally believed to be the case, by getting into the circulatory system,
- and are carried from thence into various portions of the body. Those
arriving in the spinal canal and cranial cavity seem to thrive and grow,
while the others, which may have reached the heart, lungs, and dia-
phragm, grow for a time and then perish.

Description of cystic stage—Having arrived in the brain cavity, the
-young embryo migrates upon the surface of the brain much as the em-
bryo of Tenia marginata does through the liver substance. The gal-
leries it makes are sinuous. They begin at a point and slowly increase
with the growth of the parasite and run inany direction. In from two
to three months after the first invasion of the brain the cysts have
_ grown as large as 4 hazel-nut, or about a half inch in diameter. When
examined closely they will be found incased in a thick outer skin, a sac
made by the membranes ot the brain. . Out of these sacs the parasites
may be loosened, and these resemble the cysts of T. marginata. It
differs, however, in a very important particular—instead of having a
single knob attached, tens or hundreds of these knobs may be seen as
little dots hanging from the inner surface into the fluid of the cavity,
(see Figs. 3 and 4). Each of these dots can evert itself, or push its head
out, and wili then be seen by the aid of a glass to be a perfectly de-

83
84

veloped head, having four suckers and a crown of about twenty-eight
hooks. These heads, when the cysts are ted to dogs, may develop into
as many individuals. Most of them will generally die, and only a few
of the stronger will develop. Instead of the single worm which the
embryo of 7. marginata produces, this peculiar species develops many
from each of its embryos. In this there is a compensation; for while

many of the 7. marginata embryos come to maturity, but one or two of
the cenuri survive, and thus the opportunities for the further Borpein
ation of the species are diminished.

Duration of development.—Experiments have shown that the embryo
may be found in the brain from two to three weeks after feeding, and
is then about the size of a mustard seed. Between three and six weeks
after feeding the worst symptoms of the disease occur. The canurus
becomes developed in from two to three months. After this time it
continues to grow in size and in the number of heads for six or eight
mouths, when it usually causes the destraction of the affected sheep.
When the developed cenurus is fed to a dog it usually produces adult

tape worins within a month.

"In the migrations of these parasites many are lost and destroyed. Of
the hundreds of eggs which leave the intestines of dogs few reach the
stomach of the sheep, and of these still fewer enter the cranium. Of
the few which become adult—one or two in each sheep affected—but
a small percentage nowadays arrive in the dog again. Thus of the
thousands of embryos that left the dog but a single cenurus may return.
But this cenurus, developing again into several tape-worms, is the
source of many new embryos for the re-infection of the sheep.
_ Disease.—Lambs and yearling sheep seem to be most liable to infection ;
those over two years old seem to possess adegree of immunity. Sheep
herded by dogs; those breeds which eat the grass close to the ground;
sheep which drink out of ponds or brooks in which the dogs bathe;
flocks belonging to careless tflockmasters, who leave the skulls and vis-
cera of slaughtered and dead sheep strewn through the pastures, are
more liable than others. In short, any of the conditions which help in .
the distribution of the parasites render sheep more subject to the
disease.

Symptoms and progress.—The symptoms of gid in sheep are depend-
ent upon the stage of invasion and development at which the parasite
has arrived. The invasion embraces the period from the time that the
embryos have been swallowed to the time that they become partially
developed in the brain. The stage of development embraces the re-
maining time they pass in the brain. The stage of invasion generally
passes unnoticed. Between the second and third week those animals
worst infected—for but few of those infected show signs of disease in
this stage—show symptoms of inflammation of the brain and surround-
ing tissues. It is at this period that the little parasites are active in
progressing through the tissues. Dullness, feebleness, heat in the head,
85

intense redness of the mucous membrane of the eyes, and increased
pulse-beat are characteristics of this stage. The head is generally held
-in a peculiar position, either stretched at length, turned backward, in-
clined to either side, or drooped. The intensity of these symptoms
depends on the number of invading parasites. Later, spasmodic con-
vulsions or paralysis may occur. Death may take place in about six
or eight days after the first symptoms are noticed. The diagnosis at
this stage is difficult, but depends on finding the parasites and their
channels on the surface of the brain. The former are at this time the
‘size of a mustard or flaxseed. A correct diagnosis at this stage will
influence the future treatment of the flocks. If the sheep live through
this stage no further symptoms will be noticed for from four to six
months, when a new set of symptoms will-appear. It is said that of all
infected sheep less than 2 per cent. of those which show the disease in
the early stage recover.

The symptoms of the second stage arise from two causes—from the irri-
tation produced by the little heads. thrust out of the mother bladder
and from the disturbances created by the pressure caused by the in-
crease in size of the ceenurus. :

The actions from which the disease has derived its common name in
all countries are especially characteristic. The head turns ;. the animal -
walks in a circle; it staggers, trembles, has convulsions, acts stupid;
it becomes unable to eat or drink, and finally dies of exhaustion or pa-
ralysis. The various gaits and peculiar positions assumed by the infected
animals arise from the particular location of the parasite. The length
‘of time between the attack and death also depends on this position,
some parts,of the brain being more vital than others. Death occurs in
a month or a month and a half after the secondary symptoms appear.

A diagnosis of the disease in this stage can be determined by an ex-
amination of an infected animal. Sometimes at this stage the parasite
softens the wall of the skull by its continued pressure and the spot can
be felt with the fingers. Canuri in the spinal canal are more difficult
" to diaguose. They cause the sheep to stagger and walk peculiarly with
the posterior extremities. Sometimes the disease is manifested by an
intense itching along the backbone without any apparent reason. Paral-
ysis of the hind limbs and of the rectum and bladder often result.

The gid should not be confounded with the disease caused by grubs
in the nasal cavities, which sometimes produce similar symptoms. The
false gid produced by the larve of the Gistrus ovis will cause more symp-
toms of a catarrh or cold in the head and less of the turning, which is
so very characteristic of true gid.

Treatment.—There is no treatment that can be profitably followed for
sheep thus affected. A veterinarian could in the more advanced cases
locate the position of the cyst either by inference from the character of
the symptoms or by feeling the softened spot in the cranium. He
might, by carefully cutting away or trephining the skull over the point,
86

remove the parasite and enable the sheep to recover. The intelligent
farmer might learn to do this himself, but after it is all done the cost
of doing it will about equal the value of the sheep saved. The true
treatment, and that which has saved France and Germany more than
any medicinal or surgical treatment devised, consists in prevention.

Prevention lies in the treatment of the sheep and of the dogs. As the
developed canurus comes only from the craninum or spinal canal, it is
very easy to prevent dogs from being infected by taking care that they
can not get these portions of the carcass either when the sheep are
slaughtered or after they have died in the pasture or sheep-cote. The
heads should either be rendered, burned, or deeply buried, and not
thrown into the first convenient corner.

When the skulls and viscera must be fed to dogs they should be sub-
jected to a prolonged boiling. The soup so made would be harmless.
When the lambs are known to have passed through the first stage of
the disease and are fat enough for sale, at the very beginning of the
secondary symptoms they should be slaughtered and marketed, care
being taken with the first killed to verify the diagnosis. This will save
more than any other proceeding. The treatment and handiing of the
dogs are the same as for Tenia marginata, except that T. cenurus, ac-
cording to Leuckart, develops in three or four weeks, and has to be
medicinally attended to oftener, or until the dogs are quite free from it..

The adult.— Tenia cenurus, the adult tape-worm, which grows from
the cyst and causes the gid when in the sheep’s head, resembles 7. mar-
ginata and also T. serrata, a tape-worm which the dog acquires by eat-
ing the viscera of rabbits in which the young form is encysted. T. ser-
rata is about as large and long as 7. marginata. T. cenurus is much
smaller than either, measuring when mature between 1 and 2 feet,while
the former measures a yard. It is also a slenderer species. The most
decided differences lie in the hooks of the head. Z. serrata has the
largest head, the largest hooks, and the largest suckers, the latter
being a third larger than those of 7. marginata. They are from thirty-
eight to forty-eight in number. The hooks of T. cenurus are between
twenty-four and thirty-two in number, and the slenderest of the three
species. The terminal segments also vary, those of 7. cenurus being
the smaller. The total number of joints also differ, T. marginata having
five hundred and fifty or six hundred; 7. serrata, three hundred and
twenty-five or three hundred and fifty, and 7. cenurus about two
hundred. Exact measurements of all these parts as given in text-books
enable one to definitely determine the species, but the flock-master
needs most to know that his own and his neighbor’s dog harbor tape-
worms, which are prejudicial to his flocks, and to proceed against them.

The presence of Hydatids (Tenia echinococcus, v. Siebold), (Plate XI,
Figs. 7, 8, and 9), is, if it occurs at all in this country, very rare. It
has a life history similar to 7. marginata, passing from sheep, cattle,
and pigs to dogs, and from dogs back again. In method of growth it
87

differs, forming from a single embryo large masses of cysts, which con-
tain many individuals capable of becoming adult. Its favorite situa-
tions in sheep are the liver and lungs. It may occur elsewhere. In
these places it forms large bladdery masses, whose nature can only be
. definitely determined by the aid of the microscope. As this parasite is
also dangerous to man the bladders should be handled with care, and
destroyed. The treatment of dogs is the same as for the other tenia.
Tenia tenella, Cobbold (Plate XI, Figs. 5 and 6), which causes mut-
ton measles, is a tape-worm of man, and is supposed to be acquired by
him while eating mutton through which the cysticerct have scattered.
The disease has not yet been noticed in this country, and having been
observed but seldom in Europe, is yet problematical. Mutton af-
fected would present little white spots as large as flaxseed scattered
through it. The loin muscles are most apt to be infected. Neither
this disease nor hydatids can at present be accounted a disease of sheep
in this country.
Fig.
Fig.
Fig.

Fig.

Fig.

Fig.

g.
Fig.

88

THNIA Canunus, Kiich.

PiateE XI.

. Adult, natural size (Raillet).

. Hooks, enlarged (Raillet).

. Cyst or Canurus cerebralis, Rud. The white dots are the tenia heads (Raillet).
. Ideal section through two of the dots, showing inverted pouches with heads

of the tenia developing at the bottom (Raillet).

Teenia tenella (?), Cobbold.

. Section of beef, showing imbedded cysticerci. Ulustrates the appearance of

infected mutton.

. Enlarged head of cysticerus ovis (T. tenella (?), Cobbold), the sheep measles.

Reduced from Cobbold.

Tzenia echinococcus, v. Siebold.

. Adult, natural size indicated by line (Leuckart).
. Young stages, taken from broad capsule of cyst (Leuckart).
. Liver of pig, invaded by echinococeus (Raillet). To illustrate the appearance

of invaded liver of sheep.
PLATE Xl

=
e
3
3
3
a
s
Z
5
=

 

TICERCUS OVIS.

cys

AENIA COENURUS.,

T

TAENIA ECHINOCOCCUS.
ADULT TAPE-WORMS.

Plates XIJ to XV.

The flocks of this country are infested by two species of adult tape-
worms, remarkably different in form, size, habits, and distribution.
They are Tenia jfimbriata, Diesing, and T. expansa, Rud. Each are
named from predominant characteristics.

Neumann states that European sheep harbor more species of adult
tape-worms than other animals,and enumerates ten species which have
been described, viz: Tenia expansa, Rud; T. alba, Kerr; 7. Benedeni,
Moniez; 7. aculeata, Kerr; T. ovilla, Rivolta; 7. Giardi, Moniez; T.
Vogti, Moniez; 7. centripunctata, Riv.; T. globipunctata, Riv.; T.ovipune-
tata, Riv.

The majority of these species are apparently new to science, and con-
sequently unconfirmed. Some seem to be well founded, while others
may eventually prove to be re-descriptions of other better established
species. With the exception of 7. expansa, the writer has as yet found
no traces of any of them, and it is probable that they do not occur
here.

A description of the tape-worms found here, and the diseases they
cause, follows.

THE FIMBRIATE TAPE-WORM.
TANIA FIMBRIATA, Diesing.
Plates XII and XIII.

Tape-worms in Wesfern sheep were noticed by ranchmen in the early
days of ranching, but did not attract the notice of veterinarians until
188384, when Dr. Faville, of the Colorado State Agricultural College,
first directed attention to them. (Report Veterinary Department of
Colorado State Agricultural College, January, 1885.) An earlier epi-
zootic, due to tape-worms, had been reported to Mr. Stewart, who, in
the National Live Stock Journal, for September, 1875, records their pres-
ence in Missouri sheep, and from specimens at hand determined them
as Tenia plicata. As this tenia does not occur in sheep, but in horses,
it is quite likely that Mr. Stewart saw T. fimbriata.

In a recent letter to the Department of Agriculture, the late Hon. J.
M. Givens reiterates an opinion formerly expressed by him in local so-
cieties of wool-growers, and published by him in Denver (Colo.) papers

89
90

of 188384, that these tape-worms were a cause of the larger part of
the losses among sheep, and urged the necessity of a closer study of the
subject, in order that more might be learned of the parasite, the amount
of loss it caused, and the means of preventing it. These losses had
previously been attributed to a weed called “loco,” which the sheep ate.

In obedience to instructions received from the Commissioner of Agri-
culture, the writer proceeded to Colorado in August, 1886, and began a
study of the various intestinal parasites of sheep. The studies of that
year were pursued, by invitation, on the ranch of Mrs. Mary L. Givens,
who, at great inconvenience to herself, did all in her power to aid me.
In the spring of 1887 I again visited Colorado Springs and prosecuted
other experiments, which it was hardly possible to conduct in the East.

Early in my investigations the fact was recognized that one tenia,
identified as Tenia jfimbriata, Diesing, was the most abundant; that it
was scarcely ever absent in sheep examined, and was the probable
cause of most of the tape-worm disease of Western sheep. As this
tenia was so constantly present attention was directed to it, and an
endeavor made to obtain it in all of its stages, and to learn how and
where it passed its entire life. Another fact was soon learned, that the
other species of tape-worm (Z'enia expansa), usually abundant in lambs,
was found so infrequently that it was difficult to find sufficient material
for study. The methods of study were, first, observation, and, second,
experimentation. The experiments have, as yet, been productive of
nothing but negative results. In determining so much of the life his-
tory as has been learned post-mortem observations have been the most
useful. Not only have animals been siaughtered on the ranch for this
purpose, but advantages offered by inspections of sheep slaughtered at
the shambles for consumption have been utilized. From these inspec-
tions the abundance of the parasite, the first appearance in lambs, the
different stages in growth, etc., could be learned, but it soon came to
be necessary to study the surroundings of the sheep—the corral, the
watering places, and the range—to learn under what condition the par-
asite must exist while external to the sheep, i.¢., while passing from
sheep to sheep. :

The effects of the parasite on its host (the sheep) were arrived at
from studies of the flocks and from observation of individuals at post-
mortems. The changes found were noted and careful attention paid to
the point whether certain changes were due to parasites or another dis-
ease called “loco.” As all of the sheep examined were called “ locos,”
itis evident that there was here a source of error. No certain patho-
gnomonie lesion of “ loco” was learned; as all of the * lacos” were in-
fected with tenie, the separation of characters due to each disease
was difficult. Indeed, it has seemed to me that all of the symptoms
due to the parasitic disease may be ascribed to “loco.” The characters
of the tape-worm disease are, however, well marked in lambs which
have never learned to eat this weed exclusively, and thus could be
91

studied without regard to “loco,” which, if a disease at all, belongs to
yearlings and older sheep.

Experiments were undertaken with a view of infecting lambs with the
parasites, while the lambs were kept from other possible sources of in-
fection; but these were fruitless. Other experiments wereentered upon
with a view of removing these parasites by medicinal remedies. None
of these were effective in removing the parasites from the gall-ducts,
and were abandoned until more could be learned of the life history of
the parasite, when they could again be taken up with perhaps a better
prospect of success.

The total results regarding this tenia, so far obtained, are as follows,
viz:

The parasite persists in an adult stage in the older sheep throughout
the year. :

The smallest forms appear in lambs soon after the second month of
their age, and may be found in sheep of any age throughout the year,
excepting, possibly, the winter months.

' It requires at least six months, possibly ten, to attain an adult size.

Theovaor embryosare continually passed from thesleep to the ground
throughout the year. The life of the embryo from the time it leaves
one sheep until it is found in another is yet undiscovered.

When present in considerable numbers in sheep it determines a dis-
ease which is not only detrimental to the value of the animal, but at
times causes the death of large numbers.

No medicinal remedies can be recommended which will assuredly re-
move the parasite from the host.

Many measures may be taken which may prove to be effective in two
ways, first, in preventing sheep from becoming infected ; second, in
enabling the sheep to better withstand the rayages of the parasite, and
thus carry it over the critical stage of its existence.

The lambs and yearlings are the greatest sufferers, and itis to these
that the most attention must be paid.

TANIA FIMBRIATA, Diesing.

Synonymy.—T hysanosoma actinioides, Diesing, 1834. Med. Jahrb. d. desterr. Staat.

Neue Folge, VII, 105-111. Taf. III (Fig. inverse delin.), Ej. Syst. Helm. I,
501 in nota. , :

Tenia fimbriata,; Diesing. Syst. Helm. I, 501.

Tania fimbriata, Diesing, 1856. Zwanzig Arten v. Cophalocothyleen, p. 11, 1856.
Wien.

Tenia fimbriata, Rept: Dept. Agric., 4th and 5th Annual Repts. of Bureau Animal
Industry, 1887, 1888, p. 167, Pls. I and II.

Tenia fimbriata, Diesing, was first discovered by Natterer, in Brazil,
in 1824, and published by Dr. K. M. Diesing in 1834, as a new genus,
Thysanosoma actinioides. Later, in 1856, Dr. Diesing republished this
parasite as Tenia fimbriata. (See Plate XIII.)
92

The first specimens found were detached segments, and from these
the first description was made. Natterer later found more complete
specimens and upon these the species was founded, The specimens
were found in the intestines of the following species of deer, viz: Cer-
vus paludosus, C. rufus, CO. simplicornis, C. Nambi, C. dichotomus.

A translation of the original Latin description is as follows:

Arhynchotenie, Rostellum none; mouth unarmed.

Tenia fimbriata, Diesing. Tab. V, figs. 9-15. (Plate XIII is acopy.)

Head obtuse tetragonal, large with hemispherical angular bothria; neck none;
body anteriorly lanceolate, with very short cuneate segments; posterior margin of
the upper entire, of the following crenate, of the last fimbriate on each side; the lin-
ear fimbriw rounded at the apices. Genital apertures —; length 6’” — 6”; width
1—3'". Mature segments, separate, 1/” long, 2’ wide, with lanceolate fimbriz.

This description was necessarily imperfect, from the lack of abundant
material, but is nevertheless sufficient to enable us to identity the pres-
ent species with it. Fortunately, too, excellent figures enable us to
clearly understand the fimbriate character of the species. At present
this is the only species known to possess this character. Though char-
acters founded on form are of doubtful value, until more decided differ-
ences are determined between the fimbriate tenia of deer and those of -
sheep, this decidedly strong character must serve to keep the two to-
gether. Besides, there are no strong reasons why the two should be
separate, for each is of: about the same size, a fact which we would
scarcely expect in the same parasite living in hosts of different genera;
and each is also found in hosts of similar body temperatures, habits of
life, and of feeding. That they are found in far-separated localities need
be no serious objection, for the land connection of North and South
America would permit of the infection of deer of both continents with
the same species of parasites.

Tenia fimbriata is lanceolate when contracted, linear when relaxed.
Itis quite thick, the fimbrice on the contracted specimens presenting
the appearance of plush. The segments can only be distinguished on
the more relaxed specimens. Adult specimens are from 15 to 30° in
length and about 8” in width. Immature specimens range from less
than 5™" upwaids. The greatest width is about 2°" from the free end,
from which point the segments become narrower. There are at the free
end of adult specimens from three to four or more segments which are
of nearly equal width, which have lost their contractility and are in the
process of being shed. The shedding of segments begins in youngest
specimens and continues throughout the life of the parasite.

The head or organ of attachment is depressed and tetragonal and
quite large, sitting on the neck like a pin-head; it is from 1 to 1.5™™
wide, hookless, and has four very large suckers. The sabstance of these
cups forms the greater part of the head.

The neck cr the part where seginentation begins is very short in con-
tracted specimens, but can be seen in the relaxed condition. The seg-
93

ments are very short and flat uear the head, but concave or cup-like
toward the free end, each overlapping the succeeding, and all appearing
linear on the surface of the tenia. The terminal relaxed segments are
cuneate. The borders of segments nearest the head are slightly wavy
or crenate. They soon become fimbriate even in youngest tenia; so
that the smallest specimen found demonstrated the fringed character
of the species. The fimbriw may either be contracted when they are
stout and short, or relaxed when they are flaccid and proportionately
longer. They are obtusely pointed. The segmentation in contracted
specimens is made out with difficulty. It is indicated by transverse
stria. In relaxed specimens it is plainer.

The sexual organs are symmetrically placed, two sets in each seg-
ment, each opening in a lateral pore. Each set of organs is composed
_ of a male and female portion, or is hermaphroditic. They begin to de-
velop at some distance from the head and attain maturity towards the
middle of the tenia.

Besides being remariable in the fimbriate character of its segments
this species is also peculiar in the form of its reproductive apparatus.
The male portion develops first and occupies the whole width of the
young segments. It consists of sacs connected by tubules with a large
tube which finally becomes the much convoluted efferent tube.

The ovaries develop later, and are situated at each side of the seg-
ment. They are not shown in the plate.

The uteri develop last. Each is made of a series of bags arranged
side by side in a fringe which extends along the top of the segment
from side to side. These bags open into a larger tube from which they
receive the developing embryo. The tube connects with the ovaries.
The embryos develop in the uteri, aud probably remain there until the
segments go to pieces on the ground and thus permit them to be scat-
tered. They are six-hooked and not essentially different from those of
other tenia.

Occurrence.—This tenia is found in the duodenum and gall ducts of
sheep. The former is sometimes found containing from thirty to one
hundred specimens. More often, however, there are from two to thirty.
The gall ducts are frequently completely distended by the tenic, which
pack them so tightly tbat the parasites can not be withdrawn by pull-
ing without breaking. Occasionally one, or at the most two, may find
their way into the pancreatic ducts, which they alsodistend. They get
into these ducts when young and distend them as they grow larger.

A few disjointed segments may be found below the duodeuum, but
no entire individuals. Nearly every sheep of a flock will be infected.

Distribution.—Tenia fimbriata, Diesing, the fringed tape-worm, is at
present the most common parasite of the sheep of our Western plains,
and causes by far the greatest loss of any intestinal parasite in this
country.

As may be seen by inspection of the tables showing parasites found
94

in different post-mortem observations, it has been identified in sheep
from Utah, Colorado, and Nebraska. Mr. Codweis, of Granger, Colo.,
a former sheep-owner in New Mexico, says that he has seen them there.
Mr. Samuel Collins, of Colorado Springs, Colo., who has slaughtered
sheep from California, Oregon, Utah, Nebraska, and Colorado, says
that all sheep from these States have them. Dr. Faville personally
told me that he has seen them from Oregon sheep and from sheep in
New Mexico. Mr. Stewart’s identification of Tania plicata from Mis-
souri sheep (National Live Stock Journal, September, 1875) leads me
“to suspect its presence in that State. When to these evidences of
wide-spread distribution we add those offered by the. intermingling of
Western sheep by parentage and traffic, and by the opportunities for
infection presented by the nearly unrestricted communication of the
ranges, we may believe that this distribution is necessarily wide-
spread. Its distribution at present is from Oregon and Wyoming south-
ward and from Nebraska and Missouri westward, or, more accurately,
from the uinety-fifth degree of west longitude westward and from the
torty-fifth degree north latitude southward. It coincides with the dis-
tribution of the sheep in those parts, and more especially with that of
the descendants of the Mexican or Spanish sheep with which nearly all
of the larger ranches were originally stocked. The precise limit of its
Bastern distribution is unknown, but is probably limited to those por-
tions of Nebraska, Kansas, aud Missouri to which Colorado feeders have
been sent prior to selling them to the Chicago markets.

There are at present no facts at hand to show that the parasite exists
east of the Mississippi River. In two instances a number were found
in sheep slaughtered in Washington, D. C., but these animals were said
to have come from Chicago, Ill.

Life history.—All of the life history of this tenia that is at present
known has been learned from post-mortem dissectious and microscopic
investigation.

The adults were found in yearlings and older sheep throughout the
year. No adults have yet been found in lambs less than ten months
old. The smallest stages of the immature tenia may be found in all
young sheep over ten. mouths old, They are usually most abundant
in lambs, yearlings, and two-year olds. Although a sheep may be in-
fected with a number of tewniw of about the same size, indicating an
infection covering but little space of time, it is more usual to find the
parasites of various sizes, indicating a continuous infection. The re-
tention of food and liquids for some little time in the rumen and reti-
culum may account for this in part. These varying sizes continue
from May until December. Sheep examined in May presented various
sizes and indicated infection in formermonths. No other datashowing
infection during winter months were obtained. The smallest tenie
_are found in the duodenum; those found in the gall ducts are larger.
Tenia less than 2™™ long have been found in the duodenum after the
95

gall duct has become completely packed by the parasites. The adult
_worms have embryos in their most distant segments, which are ready
to be set free. These embryos escape from the host with the feces.
Until they reappear in the duodenum of another sheep, a quarter of
an inch in length, their history is unknown.

A tenia infecting a lamb two months old, the youngest stage noticed,
is about a half inch long; as the season advances it is joined by athens,
and these increase in size. Four or five months afterward it is found
to be 4 or 5 inches in length, showing a monthly rate of growth of about
linch. From this time it gradually increases in size until the following
spring, when it becomes adult and capable of furnishing embryos for
infection of other animals. These embryos escape from the sheep, and
while many are destroyed a few.arrive at their destination in a second
animal.

Disease.—The influence that the presence of Tania fimbriata has on
the life and health of its host is not inconsiderable. The ultimate loss

~ is seen when lambs which should be fat and strong are not, and die dur-
ing the colder weather while the fatter ones survive. This loss, where
the hosts do not die, can not perhaps be accurately estimated, but is
nevertheless present, for thin, hide-bound, dwarfed sheep are not
valuable for mutton, nor do they produce as much wool as they other-
wise would.

So slowly are the parasites hatched, so slowly do they grow, aad SO
gradually do the symptoms develop, that the teniw are present in con-
siderable numbers and size before systemic disturbances in the lambs
present themselves. An experienced ranchman will probably notice
_ towards September that some of the lambs are vot growing as they
should. Later in the fall the symptoms increase. In November the
lambs, which are by this time thoroughly infected with a number of
strong, tenacious parasites, show the disease quite plainly.

The disturbances finally shown are induced at first by the local irrita-
tion produced by the worms attaching themselves to the villi of the
intestinal walls and causing a greater secretion through their strong
vermicular action. A continuance and increase of this irritation caused
by the growth of the parasite and an accession of other parasites,
finally excites chronic catarrhal inflammation of the duodenum and bil-
iary duct. To these disturbances we must add those arising in the liver
from a plugging of the duct by the parasites, which grow so large that
they distend it to a comparatively large size.

Dr. George C. Faville, in a report of the veterinary department of the
State Agricultural College of Colorado for 1884, describes the Host
mortem appearances of these animals as follows:

, Organs of thorax were normal. In the abdominalcavity I found the stomach filled
with a mass of semi-digested loco leaves. The liver was normal in appearance; gall
bladder filled with greenish-colored bile. In the duct running from the gall bladder
to the small intestines, I found a mass of tapeworms (Tenia expansa). The small in-
testine I found filled with a mass of these worms, varying in length from 6 inches to
96

5 or 6 feet. The kidneys were normal in size and color, but upon section, I found
the pelvis filled with a gelatinous material. The muscular system was exceedingly
flabby and pale in color. The body seemed to be absolutely destitute of fat. The
urine was normal, The brain showed a slight serous effusion about the base, and te
aslightly greater extent in the region of the medulla oblongata. There also was a
slight effusion into the abdominal cavity. The only other change that could be found
in the brain of these sheep was a slight congestion of the arachnoid membrane.

The above description is taken from so-called “locoed” animals, but
applies equally weil to tnie-infected sheep. Of the many ‘ locoed”
animals examined, but one or two have been free from tenie, and in
these the gall ducts were thickened and enlarged as though they had
at some earlier date been infected. Itis extremely dificult to separate
the symptoms of the two diseases, and it seems to me that many cases
of “Jocoed” animals are victims of the tapeworm. That the tenia may
tend to produce depraved appetites and the morbid craze for a particu-
lar food, is also a reason for suspecting that the loco disease may depend
in part on the tapeworm disease.

In Dr. Faville’s description there is one point which deserves atten-
tion, and that is the finding of aslight congestion of the arachnoid mem-
brane. In specimens examined by the writer there seemed to be no
undue congestion, and the arachnoid membrane, which is a vascular
one, naturally looks red or dark colored. The brain symptoms of these
avimals are such as arise from anemia rather than hyperemia of the
brain.

‘In affected yearlings which are not suspected of eating loco more
than other animals (all eat of the loco plants), the following ante and
post-mortem symptoms can be observed: Lambs that are badly affected
are large headed, with undersized bodies and hide bound skins. Their
gait is slightly like that of arheumatic. They seem to have difficulty
in cropping the shorter grass; they also appear to be more foolish than
the other sheep, standing oftener to stamp at the sheep-dogs or herder
than the healthier ones. Others do not seem to see as well, or are so
affected that they appreciate danger less. In driving they are to be
found at the rear of the flock. Internally the organs present no marked
symptoms of disease. The abdomen contains more dark-colored serous
fluid than normal; the omentum is often nearly devoid of fat. The ca-
tarrhal inflammation and thickening of the mucous membrane of the
duodenum and gall-ducts have already been noticed. The liver, in
cases of long standing, is somewhat smaller than normal; the kidneys
are sometimes-flabbier and paler than normal; the lymphatics look
somewhat darker; the muscles are thinner and weaker. There is in
all cases a diminution of fat, and in most cases the leanness of muscle
is marked. In those places where the fat usually occurs in masses little
or none is found. Associated with this condition is the presence of se-
rous infiltration of the connective tissue in the abdomen, thorax, spinal
and cranial cavities. This infiltration is the most marked in the worst
cases. The groin, the pelvis of the kidney, the spaces between serous
97

coats of the abdomen, and other spaces where serous membrane par-
tially or entirely surrounds an organ are noticeably infiltrated.

These conditions hold in lambs and older sheep. Between the worst
affected and entirely healthy individuals there are many grades. The
symptoms and pathologic lesions are those of mal-nutrition, and aside
from the lesions of the duodenum and liver are not materially different
from the systemic lesions caused by other parasites, or from inuuttri-
tious food, or from any cause that would prevent the animals obtaining
and assimilating nourishing food. A variety of other causes would
produce the same lesions.

The parasites may produce their evil results as follows: Their vermic- *
ular actions cause increased secretion of the intestine where they are
lodged, both by direct irritation and sympathetically, i. ¢., the adjacent
intestine secretes more than it ordinarily would by acting in sympathy
with the infected portion. This hypersecretion soon becomes abnormal,
and the secreting membranes become so changed that they can no
onger act physiologically. Its best purpose is in furnishing the para-
site with more nutritious fluid. The plugging of the gall ducts not only
stops the gall from flowing at proper times, but dams back that which
is secreted during digestion, and allows it to slowly ooze out after it is
needed. When the ducts are unobstructed the bladder and ducts are
lemptied at their proper times, and any interference with this flow
deranges healthy digestion. The damming back of the gall reacts on
the secretion in the smaller ducts, and this in its turn reacts on the
physiological functions of the liver cells.

The disturbance of digestion due to this impairment of the functions
of the liver and duodenum has uot a merely local effect. In the upper
parts of the small intestine important digestive changes take place, and
the disturbance of any of these prevents the proper preparation of food
for its assimilation through the intestinal wall, resulting in a loss to
the animal of nutrient material. The duodenum is held to be a very
irritable organ, diseases in it causing reflex disturbances of various
kinds. These reflex actions also lead to many systemic disturbances.
Now these disturbances are each slight, but when combined and con-
tinued through weeks and months they cause the results just described.
To one seeing a half dozen or more worms taken from the intestine of a
sheep the worms do not seem to be a sufficient cause of disease. The dis-
turbance caused by one worm in man gives rise to even greater systemic
derangements. The non-assimilation of food and reflex irritation pro-
duced by the tape-worms seem to be the chief causes of the impover-
ished condition of the infected animals. rom these causes proceed the
imperfect nutrition of the various organs and the dropsical effusions
‘resulting therefrom.

From this state of mal-nutrition all of the systemic dictatbenees can
result. The staggering gait may arise from the weakened muscular
system; the absence of fat from non-deposition of more and the con-

23038 A P——7
98

sumption of that heretofore deposited; the serous effusions from the
weakened condition of the system; and the foolish actions from the long-
continued lack of nourishment of the brain.

Sheep do not die from the tape-worm disease alone. The greatest
losses are, the ranchmen say, among the lambs and yearlings. The
majority may die during cold storms, either from freezing or from sufto-
cation while piling upon each other for warmth. They may starve to
death either from inability or lack of desire to eat. They may die from
other diseases. The tapeworm disease appears to render them more
liable to othes affections and less able to withstand the inclement sea-
son. It is therefore indirectly chargeable with the loss. Hven if the
infected sheep do not die, the parasite is still a cause of pecuniary
loss. The impoverished coudition traceable to it is a small average
loss for each animal, but for flocks of over five thousand sheep the ag-
gregate is thousands of dollars for each ranchman.

In the article of Dr. Faville, cited above, he quotes a letter * from
the late Hon. J. M. Givens, whose flocks numbered from six to eight
thousand head. In this letter Mr. Givens states his loss from dead
sheep alone for the preceding year at from $3,000 to $4,000. Fortu-
nately the loss of from four hundred to eleven hundred or more sheep
does not occur to flockmasters annually, but such losses are not in-
frequent, and may be heard of either on this or that ranch during
different years. Every ranchman knows of and appreciates the steady
though small loss arising from the depreciated value of his animals,
due to their ill condition from various causes, and which he strives by
every means to reduce, for therein lie the profits and success of his
business. From the study aud observation which the writer has been
able to devote to the tape-worm disease it appears alone responsible for
more losses than any other sheep disease on the prairies excepting
. scab. The direct death-rate traceable to it is large when compared to
the entire death-rate, and the indirect loss traceable to it is, though
inore insidious in its character, still larger, for it is ever present and
ever active.

Medicinal treatment.—Some experiments looking toward the removal
of tenice by medicines were made in 1886, Various tenic/uges were tried
with little success. The powdered preparations of pumpkin-seed,
pomegranate-root bark, koosoo, kainala, male fern, and wormseed proved
of no avail.

in order that they might be administered cheaply the proper amount
of each for ten animals was mixed with meal, bran, and salt, and fed in

 

*The letter referred to gives “loco” as a cause of the losses. Bofore his death the
Hon. J. M. Givens had concluded, and communicated to his friends of the El Paso
Wool Grower’s Association, that the loss of this winter was not due to “loco,” for
the greatest loss had occurred in young slteep andlambs. The latter had not learned
to eat “loco” exclusively, were poor, and prosented symptoms which he learned
later belonged to sheep infested with tape-worms.
99

a trough. When sufficient meal and salt was mixed with the medicines
to entice the sheep to eat it, the bulk that contained the requisite dose
of medicine was too large for a sheep to eat at once. As this bulk was
retained for some hours in the rumen, the efficacy of the dose was lost,
for the virtue of nearly all of these remedies depends on the dose passing
through the intestines in mass. Human patients are usually prepared
for the medical treatment by abstaining from food for at least twelve
hours previously ; they are then given a cathartic which is followed by
the anthelmintic. This plan of ‘treatment utterly fails in ruminants,
for neither stage can be successfully carried out in administering
these remedies by the mouth. The presence of the large ramen, which
holds a large quantity of reserve food, and into which new material may
be taken, accounts in part for this. Some of the food, if sufficiently
‘fine, in fasting animals passes directly to the manifolds and fourth or
true stomach, but a certain proportion would fall into the rumen, and
thus the efficacy of the total amouut acting within a given time would
be lost. a

These experiments failed, therefore, through the anatomical structure
of the animal and the method of administration. The presence of.
tenie in the biliary ducts is another reason why tenicfuges can not
be entirely successful in treatment of sheep with T. fimbriata. Any
medicine which would affect the tenie in these ducts would also affect
' the sheep seriously. Itis doubtful whether they can be killed or driven
from the ducts. The continued or repeated administration of remedies
that are necessary for expelling these tenic is also an objection to
their use. The parasites are continually appearing throughout the
year, and even if those already developed could be driven off, the con-
stant re-infection would necessitate other operations for their removal.
The cost of the necessary medical treatment seemed to me to more than
exceed the good results that possibly might be realized. Further ex-
periments were therefore delayed until the complete life history of the
parasite should be determined. In this history we may hope to find
some stage at which we may more profitably administer remedies.
Many prescriptions for eradicating tape worms in ruminants are given
in various journals and agricultural papers. Some of them when tried
may have proved very efficacious. Unfortunately reports concerning
the eftects of their administration are not recorded. My own experience
leads me to have little faith in them. There is a feature about them
which, no doubt, has been recognized by the ranchman who has under-
_ taken to carry them out to the letter, viz: It is the entire inadequacy
of the recipes in prescribing methods of administration, and medicines
of reasonable price as well as of certain efficiency. This oversight is
of such importance that otherwise good recipes have to be abandoned.
The Western methods of treating sheep medicinally must differ from the
Easterp methods, as the methods of sheep-dipping, sheep-shearing, or
sheep-husbandry in these sections differ; otherwise the expense of
100

treatment will be so considerable that in view of any uncertainty of
cure few ranchmen will undertake it.

Preventive treatment.—The most effective service rendered to man
and beast by the physician has been through the prevention of diseases
and the preservation of health by hygienic measures. Appreciating this,
and that effective prophylactic treatment of the sheep against infection
by Tenia jimbriata could not be realized except by the most thorough
knowledge of the complete life history of the parasite, my attention was
turned to the investigation of its younger stages and those of other un-
armed teenie which were available. Such are the difficulties of this in-
vestigation that the gap in the life history, which may exist between
the time when the embryo passes from the sheep until it is found, less
than a quarter of an inch long, in another sheep, has not been completely
investigated.

From the present knowledge of the development and life of this par-
asite there have arisen more difficulties in forming rules of prevention
than was at first anticipated. The presence of the adult and young par-
asites throughout the year, and the methods of Western sheep ranching
are factors which are all-powerful in keeping up the tape-worm disease.
The case is not a hopeless one, however, for there are certain phases of .
feeding and watering the sheep which can probably be advantageously
changed, both for the prevention of this and other diseases.

The feeding occurs on the prairie and in the corral. I would recom-
mend that the ewes with their lambs should be pastured on a portion
of the prairie that had not been run over by sheep for some months
previous. They could be driven to the new pastures about the time
that the lambs begin to nibble at the grass and drink water. After the
lambs are weaned they should be changed to fresh uncontaminated
pastures until winter, and other older sheep put on the range vacated.
If there be sufficient range the lambs could be kept on as nearly unin-
fected ranges as possible until they become two-year olds. In feeding
lambs on grain and hay measures should be taken to keep the food
from the ground. The grain should be fed from troughs placed either
on a board floor that could be cleansed or on ground kept scrupulously
cleaned of all droppings. The hay should be fed from racks. The
corrals for the lambs should either be fresh ones or the old ones should
be periodically and thoroughly scraped out and cleaned. They should
not be put with a greater number of old sheep than is absolutely nec-
essary.

The watering occurs at various places. The usual method is the
watering at rivulets or ponds. This should be done, but such places .
should be fenced in and troughs provided into which the fresh water
could run. These troughs should be raised a little above the surface of
the ground so tliat they could receive no surface drainage. By the aid
of pumps and wind-mills this could be easily accomplished. Most water-
ing places are so situated that by conducting the water through pipes
101

or boxes but little expense would be necessary to guide it into troughs.
These troughs should be kept clean. The lambs should not be allowed
to drink elsewhere, nor to eat grass in moist places unless it is abso-
lutely certain that these places are uninfected. The location of corrals
so that they either surround water or that the drainage is from them to
the water seems to be a most harmful practice. It not only makes the
water fouler but renders it more likely to hold parasites. Herders
should be instructed neither to feed nor water at the prairie pools. If
there are places where it is advisable to water they should be prepared
like the watering places at the corrals. The nearer the ranchman can
arrive at giving the lambs pure fresh water the less infected with para-
sites will they become. The salt for the lambs and young sheep should
be fed from boxes placed near water places and kept constantly full.
They will take no more than they want and will be all the healthier if
they have all they need. If they are deprived for a time they may at
first salting eat more than is good for them. A little eaten daily is
physiologically better than the larger quantity eaten at intervals. The
object of feeding the salt at watering places and from boxes is to keep
them from licking the dirt where salt has stood and to keep them from
eating the prairie alkali. In addition to the opportunities afforded them
of being infected with parasites from the salted ground there is the in-
jurious effect of the swallowed sand. This sand often packs away in
the gall ducts and produces disease.

It may be when the gap in the life history of Tenia fimbriata is
known that a single measure of prevention will eradicate it from the
flocks. Until then the general measures prescribed above are to be
recommended.

There are various minor precautionary measures to be fulfilled that
will help affected sheep to live through the colder winter, and finally
to render effective service in spite of the parasite. The post-mortem
examinations have led me to expect that from 80 to 95 per cent. of each
flock is infected. Now, were all of these to suffer as some of the more
diseased do, sheep-ranching would be at its end. Fortunately a sheep
may have a few parasites and not be seriously affected by them. This
is shown by the fine, large sheep slaughtered which are passably fat and
yet contain teniw. It is a frequent remark of the ranchman that if
he could carry his lambs and yearlings through they would do well
enough afterwards. It is these younger and growing animals that suc-
cumb soonest to the parasite. It is a rule that all young and growing
animals are more seriously disturbed by the presence of parasites than
older.ones. Young lambs born in May or June have necessarily but a
short time in which to grow before the cold season. When food is
plenty, and there is no disturbance of their digestion, or other ailments,
they enter winter strong enough to endure the weather without partic-
ular suffering. Interference: with digestion, lack of food, or any ail-
ments render the lambs so much the weaker, and consequently less able
102

to endure the winter storms. The parasites interfere with digestion,
and to overcome their evil effect means should be taken to supply easily
digestible and fattening food, which may replace and add to that lost.
Many ranchmen already feed their lambs extra grain during the fall,
and have learned that not only are their losses diminished, but that
the lambs become larger and stronger as well as fatter.

Formerly the ranchman depended, as many do still, entirely on the
prairie for grass throughout the season. Of late years many are feed-
ing more and more hay during the winter, and find that they profit by
it in the diminished death-rate and the improved condition of the flocks
in spring. This fall and winter feeding is, then, to be especially recom-
mended as a remedial measure against losses among tape-worm. infested
sheep. With increased prosperity, flock-masters are adding to their
shedding at the home corrals. Though the first cost seems considerable,
such are the evident benefits in preventing losses during the extremely
cold snaps and blizzards, that not only should they be built at the home
ranches, but also at the outlying ones where now, with few exceptions,
none are to be found. . .

The water atforded sheep, more especially lambs, should, if possible,
be made warm during the coldest weather. The temperature of sheep
is about 103° Fah. In giving them water which is less than 35° Fah.,
the heat which is necessary to raise the water to the temperature of the
animal is withdrawn from other portions of the body, and digestion is
often disturbed and less water is drank. Experiment has proven that
animals fatten better on warm water, and were it practicable no water
cooler than 60° Fab. should be offered to sheep. The maintenance of
the drinking-water at this temperature for the use of the lambs and
other home stock would probably repay the Western ranchman, as it
certainly would the Eastern farmer. This is impracticable at some
ranches, but there are many home ranches where lambs and blooded
stock are kept at which the system might be pursued with advantage.

There is another possible chance of infection which there is no known
means of remedying. If, as is probably the case, the tenia embryo
passes with but little modification from sheep to sheep, there is then
a certain amount of infection that may occur between the ewes and off:
spring when suckling, the lambs becoming infected with embryo by
rubbing them from the mother in nosing around while suckling. As
older sheep have the tenic, and as lambs become infected after being
weaned, this method of infection is only one of many.

No medicinal remedies or preventives can be advised. The recom-
mendations above are directed toward lessening the chances of infec-
tion and preserving the health of the animals.

It is hoped that the gaps in the life history of Tenia fimbriata, or
others of our unarmed teniew, may yet be filled out. With a knowl-
edge of this history, the methods of prevention would be evident to all.

The flock master should take pains to examine the sheep which die and
103

inform himself, as nearly as possible, of the cause of death. In case of
the presence of tape-worms, causing sickness, he can soon inform bim-:
self of their abundance, of the absence of other disease, and of many
other things. He can soon judge whether others of his flock have them,
and can more intelligently set about their treatment. A careful study
of each case-will then place the observant man in possession of many
facts which will help him in the proper management of his flock.

The above recommendations have been written with a view of keep-
ing the food and drink of the animal as clean as possible. Other pre-
cautions will suggest themselves to tLe ranchman.

Post-mortem examinations. —The tables herewith presented are the
results of post-mortem examinations of sheep, some of which were killed
expressly for the purposes of investigation. Others were examined while
being slaughtered for food, either.on ranches or at the shambles in Col-

. orado Springs, Colo., while in other cases examinations were made upon
dead sheep found either at or in the vicinity of various ranches. From
the wide-spread distribution of the disease, the notes aresuch as could
be taken from nearly all localities, and can not be ascribed as purely
local causes. Where the observations were taken from the sheep raised
in States other than Colorado, the State from which they came is given.

In addition to the presence of Tenia fimbriata, the occurrence of
Tenia exapansa has been noted, and also of Tenia marginata, which
occurs in sheep in its cysticercal stage. The examinations at the sham-
bles could not be conducted with the same accuracy while hunting for
Tenia fimbriata; the occurrence of the cysticerci is, therefore, omitted
in the post-mortem observations of June 7, 1887, to August 15, 1887, in-
clusive.

Table A shows that feniw occur in sheep throughont-the year. It
also indicates a wide-spread distribution.

A.

 

Tr. fim- Cysti- | T. ex- No.
No. ep ne Location. |briaia oc-| cerci oc- pansa oc-| of ear-
. examines r . curred in-j¢nrred in-jcurredin-| tags.

 

Sept. 16 : Colorado...
18 aici aiw-oadl

Oct.

Nov.

 

 

 

 

 

 

 

 
104

A.--Continued.

 

Tf. fim-' | Cysti- T. ex- No.
Location. | briata oc-| cerct oc- | pansa oc-| of ear-
curred in-|curredin-|carredin-| tags.

No. sheep | No. lambs

Dates examined. | examined.

 

 

   
 

Colorado. - 1 1 Tl seeder

   

Ne

10 Utah......
5 Colorado. .
4 uel Olecjeciecs
site wedentand AO ex:
20 ---d0
came sieese aa aclO crac
4 | en

  

 

 

 

 

 

 

 

 

136 32 139 | 42 5

 

* From June 7 to August 15 inclusive, cysticerci were found-in most of the animals examined.
1 No tenie found in the two lambs.
t No tenie found in lambs.

Experiments—November 30, 1836.—Six lambs, selected froma bunch that had been
kept in an inclosure since the 15th of October, were, with two yearlings and two two-
year-old wethers, crated and sent to the United States Veterinary Experimental Sta-
tion at Washington. The lambs were from a collection of the runts of a large flock
which had been fed on hay made from prairie grass and on coarse corn-meal and
bran before November 30. They were watered from tubs, the water being drawn
from a well and a pond near by. The land on which the hay was grown had not
been crossed by sheep since spring, at least. The water was clear. The chances of
infection from these sources were small. The corral where they were kept was a
good warm shed, located amidst others, with a small adjoining yard. he dogs, of
which there were two and sometimes more, had free access by jumping the hurdles;
but I do not remember ever having seen one in the inclosure after the lambs were
adinitted. With these lambs were two old bucks and a few sheep, which were either
lame or otherwise ailing. They arrived in Washington, D. C., December 4, 1886,
and were afterwards placed in stalls where they could not be re-infected excepting
from each other. As Table B shows that there were no adult tenia in the lambs,
reinfection could only be through the four older sheep confined with them. Rein-
fection could not possibly have proceeded from some Eastern sheep confined with
them, for these sheep, when examined, had no T. fimbriata. No dogs were admitted
to the box-stalls where they were kept. Their food was Eastern clover and mixed
corn and bran. They were furnished with well-water and salt. The adults were
numbered 101 to 104; the lambs from 105 to 110.

December 9.—T wo Eastern lambs, Nos. 111 and 112, were put in the pen with Nos.
101 to 110 inclusive, Nos. 111 to 118 were a number of Eastern coarse-wooled sheep,
bought for experimental purposes. /

December 13.—Nos. 111 and 113 were found to pass mature embryo bearing proglot-
tides of T. expansa.
105

December 17.—Fed Nos. 105, 107, and 109 with proglottides of T. expansa from Nos.
111 and 413,

December 31.—Lambs Nos. 106, 108, and 110 were put in a pen with Nos, 111, 112,
113, and 115. And sheep Nos. 101 and 104 were put with Nos. 114, 116, 117, and 118.
Later on some other changes were made, but as the Eastern sheep were found to con-
tain no tenie when examined, these changes had no result, and could not have
affected the result in other ways.

The object of arranging and re-arranging these sheep was to give
possible chances of infection to the uninfected sheep.

Table B is compiled from data obtained from lambs born in 1886;
from four wethers, which, with six of the lambs, were removed to the
experimental station in Washington, D. C., and from a few lambs
_ born in 1887, The sheep marked M, killed June 25, was also adult.

Table B shows that the Tenia fimbriata begins to appear in two or
two and a half months old lambs, that they continue throughout the
winter and gradually attain maturity as spring approaches. Each of
the tables, A and B, shows that adult tape-worms were to be found.
throughout the year.

B.

 

Time in weeks.

No. of Number Agein

 

Date. lamb. pene Length of 7. fimbriata.| eons « sieacy koe
a gaia Wash- -
ange. | ington.
1886. :
OGti 21 scccicn cusewecctossserwetisas? A | Few... | &"andunder........
B/ Many...) lu and under.......
© iis NOs ca.| esa lO ease cereeessees
Diliins
E
¥
G
7 i
I
105
107 jjafe seis PEREGO LOM 2 cceigronjete:aiasane

   
  

 

109 ; 100+....} 5™™ to 10™. ........-.

  

108 | Many...| J°™ 10 7™ 1.2.2. eee ee _ 3d 12 6
mee ; tein emens 103 | 504-... | Immature and adults 43 22 15
Se a diaaien pau Saray 101 wterd(l Oiiiae dg ste soieiara’e oes
iiaiasa ss aiaaies wrens (e upivedess) claveutaioiayets 106 T™ to ]5em,
ajeesalace mitra aeaio(e etecwinaieee 102 Immature...
cist Gtecleiaite neal acter! 104 a2 UO edie
110 Adult
K Qem_
5 L -.[.-- do
June 25. M -| 2™ to 5¢"— adult

 

 

 

 

 

 

 

 

* The age is that of the lambs and is estimated May 15.

Nos. 101 to 104 and M were adult sheep; all others were lambs.
Adult teniew contained embryo.
Post-mortem eraminations—December 26.—No. 105 died. It contained four small

Tenia fimbriata, the largest about 2 long, and fifteen cysticerct of T. marginata, each,
less than 1°” in longest diameter.
106

December 29.—Killed No. 107. It contained nineteen small T. fimbviata, the largest
about 4°™ in length, and twenty cysticerci, the largest a little over 1°™ in diameter.

December 30.—Killed No. 109. It contained over one hundred small teni@, ranging
from 5™™ to 10° in length; also a few small cysticerci, apparently of same age as in
107. ;
January 8.—No. 108 died. It contained three specimens of Teria expansa ; one of
these was adult; many small T. fimbriata, varying 1°" to 7™ long; also six cysticerci,
somewhat larger than tho earlier found.

April 20.—Killed No. 106. It contained many T. fimbriata, over twenty-five in all,
which were over 7'" in length; none were smaller. The duodenum and gall ducts
were packed. None were adult.

May 7.—Killed No. 110. It contained one adult Z. fimbriata and several cysticerci.

March 14.—Killed No. 103. It contained from fifty to sixty tenia from 7° to 10°™ in
ength; four of these were in the gall ducts and were among the largest in size. Te-
nia immature to adult.

March 29.—Killed No. 101. Found tenic in duodenum, gall ducts, and pancreatic
ducts. The gall ducts were engorged; the liver smaller than normal. The tenie
ranged in size from 7™ to 14; three were adult. There were three cysticerci.

April 28.—Killed No. 104. Found five teni from 2™ to 4e™ in length, but no cysti-
cerct. a

April 28.—Killed No. 102. Found fifteen tenia. The largest were not over 7™ in
length, and immature. There were two csyticerci.

Table C is made up from data,obtained from the six lambs, Nos.
105 to 110, inclusive, transported from the prairies to Washington. It
shows the comparatively slow growth of the parasite; also the abun-
dant infection of some of the animals so long as they were exposed to
infection. It also presents either the possibility of infection after they
were taken from the prairie or the retention of the embryo in the rumen
through aconsiderable time.

 

 

C.

No. of | - Weeks |Weeks | Weeks
Dat No Agein| Tenia Teenice after | after | after
ate, * | weeks. | jimbri- size. October|Decem- | Decem-
ata. 15. ber 1. | ber 31.

105 32 10

107 33 iL

109 33 11

108 84 12

106 49 27

110 51 29

  

 

 

 

 

 

 

 

 

 

October 15, the date on which the lambs wore taken from the prairie and corralled.
December 1, the date on which the lambs were received in Washington.
Decomber 31, the date on which the adults, Nos. 101 to 104, were removed.

Lambs K and I, Table B, show that the tenia was developed to a
length of 2™ in less than ten or twelve weeks, for the number of tania
found shows a slight infection and some time may have elapsed after
the birth of the lamb before its infection.

Lambs A to I, Table B, show that in from twenty-three to twenty-
eight weeks the tenia may develop to 8 or 10™ in length, and that the
107

infection is proportional to the time exposed. The infection is, how-
ever, a variable quantity, and no definite statements can be deduced.

As the lambs do not begin to nibble grass and drink water until some
few days atter their birth, the development of tenia in K and L prob-
ably required not over two months. Lamb A, examined October 21,
about twenty-three weeks after birth, gives, when compared with K
and L, an approximate rate of growth of the tenia of 2™ a month,
more or less. The rate of growth must so vary at different times that
no definite rate can be determined at present.

The tenia of No. 105, one of the same lot of lambs as the foregoing,
were no larger after thirty-two weeks than those of K and L after ten
weeks. This points to a recent infection of No. 105, 4. e., within ten
weeks, or about the time the lambs were taken off the prairie and re-
ceived into the corral. The twniw of Nos. 107, 109, 108, and 106 coin-
cide with this; but the lambs No. 109 and 108 also point to a later in-
fection, as many very small teenie were found in them. No. 108, which
had tenie 1°" long six weeks after its receipt in Washington, would
lead us to suspect a recent infection; but this is not necessarily the
case, as the influence of the rumen of the sheep in detaining the para-
site for a length of time has yet to be learned. The absence of young
teenie measuring less than 7™ in No. 106 at sixteen weeks after its
last association with an animal containing adult teniw and twenty
weeks after its arrival in Wasbington is also of interest in that it points
to infection of the lamb from the adult sheep associated with it. No.
110 shows avery slight infection, and one, judging from the age of
teenie, that could have occurred in Colorado.

The six cases show a slow growth of the parasite; they atso point to
one of two things: That the tenic are, as embryos, retained in the
rumen for some time after being swallowed, or that these teniw are
continually infecting their hosts by the diract method; that is, the
embryos passed by sheep, with little or no preparation, pass into other
sheep and develop witbout the intervention of an intermediary host.
_ So far nothing has been found to absolutely prove or disprove the latter
statement. The infection, as shown by the various sizes found in these
lambs and other sheep, points to a continuous infection nearly all the
year. (See Tables A, B, and C.)

Nos. 106 and 110 indicate a cessation of the infection for the length
of time it required the smallest (7°™) to attain their size. Lamb A in-
dicates the time to be something less than twenty weeks, or at the
period when they were received at Washington. Nos. 106, 107, 108, and
109, which had been confined eleven and twelve weeks, show as great
infection as has been seen. This would happen with animals which
were being infected in confinement, for the opportunities of infection,
if the infection should prove to be direct, are greater. Various condi-
tions, as the weather, food, water, etc., have so much to do with the
problem of infection that far more data are necessary.
108

The fact of slow development and continuous infection are the main
points brought out in this experiment. Continuous infection is natu-
rally one of the results where tewnice are constantly developing and
’ shedding ripe proglottides laden with embryos for the infection of other
hosts. Continuous infection also leads me to suspect that no interme-
diary host is necessary for the contit:uance of the life of the embryo.
This proceeds from the fact that no single species of mollusk, insect, or
other animal is to be found at all seasons and places necessary to suit
all the conditions under which we fiud the host infected.

Experiment No. 2.—A lamb dropped at a slaughter-house in this city was kept with
its mother in an uninfected stall.

The lamb was fed on January 10, 1887, with a large quantity of proglottides of
Tenia expansa from No. 108. The embryos were found to be alive and moving before
feeding.

On March 20 the same lamb was fed with proglottides of T. jimbriata from No. 103.
These contained live embryos on the 18th instant.

On March 29 fed the same lamb with proglottides containing embryos of T. fimbriata
from No. 101. °

On April 19 this lamb was killed and nothing was found except afew white spots
in and on the liver. The experiment bad no results.

AN EXPERIMENT TO INFECT LAMBS WITH TANIA FIMBRIATA.

Experiment No. 3.—May 23, 1837, placed fifteen ewes with unborn lambs in three
box-stalls. They were fed on alfalfa, hay, corn, and bran. Their water was drawn
from a hydrant near by. The ewes being thin in flesh, and taken from the prairie
grass and placed upon dry feed, thrived but poorly. Between May 23 and May 29
eleven lambs were born, which lived until the close of the experiment. Five of the
largest and oldest were placed with their mothers in stall No.1. The remaining were
divided between two stalls, Nos. 2 and 3.

These animals were removed from all sources of infection through
food and water, and the lambs had never been exposed to any source
of infection. The ewes were suspected of being infected with T. jim-
briata. If the lambs became infected they would either take them of
their mothers or from their feed. Between May 26 and June 15 the
lambs were fed in stall A several times each with a number of ripe
proglottides from adult teniv. An interval was left between each
feeding, and each lamb was fed at least three times. The other lambs
were not fed. All but two of the ewes were found to contain adult
teenie when examined later.

The lambs and ewes were killed in nearly equal lots on June 25, July
15, and August 1.

June 25, killed one ewe and one lamb from pen No. 1, two ewes and one lamb from
No. 2, and three dry ewes from No. 3. Lambs uninfected. One ewe had tenia.2-™
long.

July 15, killed two ewes and two lambs from No. 1, two ewes and two lambs from
No. 2. Lambs uninfected.

August 1, killed two ewes and two lambs from No. 1, and two ewes and two lambs
from No. 2. Lambs uninfected.
109

The lambs were kept for two months, and were not infected in this
time. This experiment shows that either a longer time is necessary for
jofection or that the embryo has to undergo some development or prep-
aration that was not allowed and of which we are ignorant. The speci-
mens fed were taken from slaughtered sheep, examined with a micro-
scope, and fed by placing the proglottides which contained living
embryos in. the lambs’ mouths and waiting until they had been swal-
lowed.

The lambs while living with their infected mothers should have been
infected, providing infection by embryos fresh from the host be possible.
As this was not the case, further preparation and development of the
embryos outside of the ovine host seems necessary.
Fig.
Fig.
Fig.
Fig.
Fig.

Fig.

Fig.
Fig.
Fig.
Fig.

Fig. 11.

Fig. 1

So

Fig. 13.
Fig. 14.
Fig. 15.

1
2
3
4
5

6

110

TANIA FIMBRIALTA, Diesing.
PLatrE XII.

. Adult, natural size. From contracted alcoholic specimen.

. Head, edge view, x6.

. Head, side view, X6.

. Head, top view, x6. /

. Portion of segment: a, genital pore ; b, cirrhus pouch; c, seminal appara-
tus; d, the efferent tube; e, tae rudimentary uterine apparatus; f, vagina;
g, the receptacle of the semen; h, fimbria.

. Portion of segment more mature than Fig. 5: a, genital pore; b, cirrhus
pouch; d, efferent tube; e, the uteri.

7. The uteri enlarged.
7a. The uteri still further enlarged, showing the contained embryo.

3.
9.
Fig. 10.

9

we

A half-grown tienia, showing the fimbri:e, x2.

Fragment of tiwnia from near head, showing the lateral excretory vessels.

Termiual portion of adult, x2: a, segments which have lost their contractil-
ity; b, separated segments.

External reproductive apparatus, x40: a, genital pore; b, cirrhus pouch; e,
penis. : . i

Adult segment showing the symmetrical arrangement of the reproductive
apparatus: a, a, genital pores; b, b, uteri; c, c, fimbria.

Embryos as they exist in the uteri: a, a, envelopes; b, b, embryo.

Embryo showing envelope and its six hooks.’ :

Youngest tenia found. Natural length indicated by lines at their sides.

All specimens except figures from 1 to4 and 15 were drawn from fresh preparations.
PLATE XII

 

west

 

iI, >

re

A.Hoen & Co, lith, Baltimer

TAENIA FIMBRIATA.
(The Fimbriate Tapeworm.)

Geo. Marx, del.

 
112

TANIA FIMBRIATA, Diesing.

PLATE XIIJ.—Diesing’s original figures.

Fig. 1. Adult, natural size.

Fig.

Fig.

Fig,

Fig.
Fig.

i
Fig.

. Head, side view.

Head, top view.

. Segments near head.
. Segmeuts further removed from head.
. Some still more remote.

From near end.
PLATE XHI

 

AGA ENO
ARO

  

“panes 4

   

 

  
   
 

  

AA ss

Avy VAAN Trin VAN AWN

A.Hoeu & Co. Lith, Baltimore,

Geo. Marx, del.
TAENIA FIMBRIATA.
 
THE BROAD TAPE-WORM OF SHEEP.

TANIA EXPANSA, Rud.
Plates XIV and XV.

Tenia expansa, the Broad Tape-worm, is one of the best known of the
internal parasites of sheep, because of its flatness, length, and large
size. In summer and fall it is quite abundant. ' The amount of pecun-
iary losses occasioned by its ravages depend upon the season and its
abundance in affected flocks. It was introduced into tiis country from

‘Europe along with theimported flocks which harbored it. Since then
it has been parasitical on our flocks from generation to generation. It
is now distributed from the wooded hillsides of New England to the
grazing lands of Georgia, over the fertile prairies of Ohio, Illinois, Iowa,
and Nebraska, and the boundless prairies, basins, and mesas of Colorado,
Utah, California, and Oregon ; in short, over every sheep-grazing local-
ity in the United States. Reported outbreaks from this vast extent of
country are comparatively few and scattered, but are sufficient to warn
us that when the pastures become narrowed, older, and overstocked, we
may expect the same trouble with this and other parasites as has been
experienced by sheep raisers through all time in the more densely pop-
ulated districts of other countries.

Description.—The entire worm measures in length about 5 yards, and
in width from one-twenty-fifth of an inch at the head to a half or three-
quarters of an inch at the tail. Its thickness is from one-tenth to one-
twelfth of an inch. These dimensions vary greatly, depending on the
contracted condition of the worm when measured and on its state of pre-
servation. Adult specimens taken from sheep may average less than 4
yards, or may slightly exceed 5; but they never, in this country at least,
attain that gigantic measurement of 100 feet ascribed to them by Eu-
ropean observers. The head is somewhat larger than the neck, and
neasures one-twenty-fifth of an inch in width. It is smooth on the end
and has its four suckers directed anteriorly. Its neck, or that portion of

- the worm immediately succeeding the head, which is unsegmented, is
shortor lacking. The body of the worm is apparently made up of a series
of very short but extremely wide joints, which vary in length and width
in the successive portions of the body. The first rings of the tenia are
very short and narrow; the others are longer, but are always broader
than long. Those segments which are about two thirds the entire length

23088 4 P—8 a
114

from the bead are the longest. From these to the end they become grad-
ually shorter and wider. In width the segments gradually increase from
the head totheend. When first collected the texture of the worms is
usually opaque and white, and it is only by allowing them to stand in
water that they become transparent enough for study. It can then be
seen that each segment is bilaterally symmetrical—that in each half is
an independent set of genital organs. These become apparent ata little
distance from the head, but show in their best development about half
the entirelength from the bead. From this point on the segments be-
come more and more opaque tothe end. The genital organs first appear
as a little horizontal line on each side; gradually a little rosette grows at
the end of each line; these disappear and the segment becomes filled
with the young eggs or embryos, which form the opaque mass. The ex-
ternal genitals consist of around pore on either side of each segment, in
which is a miuute dot, the opening of the vagina, and an exserted in-
tromittent organ. The apparatus is called hermaphroditic, ¢. e., each
half of the segment is capable of fertilizing itself; but it is likely that
cross fertilization also occurs. Fertilization occurs about where the
dots which line each side of the worm appear plainest. From this
point on the eggs are developed into embryos until the end of the worm
is reached, when the segments are prepared to retain vitality as indi-
viduals for some time after being ejected with excreta to the ground or
water.

Besides the reproductive apparatus there are two so-called excretory
canals, one on each side of the worm, running the entire length. I
have not observed cross-canals, such as occur in the armed tenie, as in
T. marginata.

There is no alimentary canal. The nervous system is very rudiment-
ary, consisting of little more than bundles of nerve fibers. The suck-
ers are each supplied with their special fibers, connected together, and
each segmentis supplied bv two long nerve bundles which run parallel
to the excretory vessels on either side. Absorption of nutrient material
or feeding takes place through the surface of the segments.

The young ezgs or embryos are polyhedral by pressure, and measure
about 0.05 to 0.07" in diameter. They have usually two envelopes,
between which a considerable amount of oily material is held. They
may have three such. Around the embryo is a pear-shaped apparatus
whose small end is surmounted by a cap with shredded periphery. The
embryo itself is contained in a cavity in the large end of the pyriform
covering, and when alive can be seen moving around init. The em-
bryo seems to bea highly refrangent mass of protoplasm provided with
six hooks, and does uot look essentially different from the embryos of
other tape-worms. The cap with shredded edges is the remnant of a
mass which originally included and covered the embryo and its balloon-
like expansion. No attempt has been made by the writer to work out
its earlier embryology. :
. 115

The next stage of the embryonie tenia found was taken from a lamb.
Tn this stage the young worm (about ?"™ long) is well outlined. Ithad
a head with four suckers and a short unsegmented body. The next step
in the development showed the body segmented. In one or two speci-
mens I have seen a little loop with its convex end projecting towards ©
the outside, but have not yet been able to determine its significance.
Between these stages and the adult the different steps of development
are easily filled in by a study of a single worm.

Occurrence and distribution—Although there is a periodicity in the
appearance of the broad tape-worms among lambs, causing at times epi-
zootic outbreaks, the worm may be found throughout all months of the
year in localities where it occurs. No section of the United States
seems to be entirely free from it. They have been found in winter, in
spring, in summer, and in the fall, in the intestines of lambs examined
‘at the abattoir. They are not so frequentin winter and early spring as
at other times, but seem to be more abundant in some localities than in
others, though this may be due to unequal opportunities of observation
in all places. -A less number was found in the West than occur in the
East. Conditions of climate and soil also seem to have some influence
on the appearance of the tape-worms. Damp, warm climates and
heavy, moist soils appear to be more favorable to their preservation
while on the ground. But none of these factors would seem so favora-
ble to the growth and life of the tenia as holding the sheep on over-fed
pastures, as demonstrated by experiments elsewhere related.

Differential description—Tenia expansa differs from 7. fimbriata in
the method of shedding its segments. Instead of maturing a few of .
the segments at a time and shedding them, as the latter do, whole sec-
tions ripen and pass away, so that an examination of a sheep which

‘has been observed to pass proglottides during a past week will reveal
but little more than the head of aworm. The exact length of time that
is consumed by the worm in maturing, so that it all passes away, is
undetermined, but it is nevertheless an important factor in the disease,
for after the worm is passed the lambs begin to recover. From what
was learned and seen of the disease the opinion was formed that the
worms do not retain their adult size more than a month. The heads,
which are left, develop slowly and form new adults. They may not
cause so much disturbance at this time, however, for the lamb becomes
older and better able to withstand them.

The rate of growth of the broad tape- worm is very rapid as compared
with that of Tenia fimbriata. This is easily demonstrated by the fact that
T. expansa are found 2 to 5 yards long in lambs from two to four months
old, while 7. fimbriata are scarcely as many inches long in lambs of the
same age. If we suppose the lamb to become infected during the first
month. of its life, the age of the tenia in the above lambs would not be
over three months, which would give an average growth of nearly a
yard per month. This enormous increase in size is au important factor
116 “

in rapidly developiug disease in the young lambs. The Tenia fimbri-
ata, on the contrary, slowly develops a disease which culminates in
older lambs.

Life history.—The life history of Tania expansa is only incomplete
in that portion of its life which it passes outside of the host. Just
exactly what happens to the embryo-containing egg, between the time
that it escapes until it is again found in sheep as a little head with
four suckers and a short tail-like appendage is not known, but from our
present knowledge may be inferred with a tolerable degree of accuracy.

No one has yet been able to either develop these embryos in water
or to feed them and produce an infection in sheep. So it has been sup-
posed by reasoning from the life history of other forms of tenia, that
these embryos must pass a portion of their development in some of
the minute animals which inhabit the grass and water of sheep farms,
From my own studies, although I have not yet been able to produce
tape-worm disease by feeding the embryos, I think that the above view is
fallacious, and that these embryos need not pass any of their existence in
other invertebrates. Dr. F. A. Ziirn (Die Schmarotzer, p. 191, 1882) is
authority for the statement that “the disease is also present in sheep
which have been fed entirely in the stalls, though more especially
among the younger and youngest of a herd which are sent to the
pastures.”

Experiment to demonstrate method of infection.—About the middle of
May, 1888, six lambs, from three to four months old, were bought on
the market and added to the flock at the Experimental Station of the
Bureau. This flock was kept in a small stable with an adjoining hill-
side yard. They were fed on clover and grain from the market, and the
water was drawn from a well near at hand. The yard was sufficiently
large to be grassy, but they soon ate it down to the roots. In one cor-
ner of an adjacent pen was an iron trough, kept full of water. After
a rain the water might have stood in the yard for a day or two ina
small puddle, but there was no so-called permanently standing water
which could have harbored insect life. There were already on the
place three lambs, with their mothers, which had been raised there that
season. ;

May 16.—T'wo lambs were fed by drenching with the embryos or eggs of Tenia ex-

AN8A.
: May 22.—An iron trough was prepared with w grass bottom, and then filled with
water. A quantity of segments of 7. ecpansa were scattered in it, aud at first only
two of the lambs were allowed access to it. Afterwards, all were allowed to go and
drink out of it. .

June 11.—Slaughtered one of the lambs, which had been drenched with 7. expansa
embryos May 16, and had since been held in the yard with the trough prepared on
May 22. No tenia were found. The experiment was thereforg of negative value.

After these dates the lambs were neglected, so far as feeding experi-
ments were concerned, until fall,

June 21.—One of the experimental lambs, which had previously been fed with ripe
segments of 7. expansa, was killed. It wasin poor condition. No tenia were found
117

in it, but numerous scars of T. marginala furrows on the surface of the liver. It was
also found that numerous white patches, which were scattered along the mucous
coat ef the small intestine, were due to a species of coccidia. As the latter disease
has not been seen since that time, and as there was a possibility that the lamb had be-
come infected with the coccidia from the dirt thrown ont of neighboring rabbit pens,
where the disease was abunéant, it has not since been studied. The results, so far as
T. expansa is concerned, were negative. °

October 10.—A ewe lamb was examined which had died some hours previously ; but
one cysticercus was found.

October 13.—A young buck lamb was pmanniund: which was bought in May with his
mother, soon after birth, from a neighboring slaughter house and was one of those
which is referred to as raised on the place). There were found a quantity of young
teniae, many aduit and young of Strongylus contortus, a few young Dochmius, and a
few Trichocephalus. This lamb was one of the two that was drenched with eggs on
May 16. He had pastured with, the others, which it was subsequently learned had
adult tania, and which had been purchased supposing them to be infected.

October 9.—A buck lamb was examined, one of the six purchased in May. Old
cicatrices of Tania marginata were found in the liver, six Cysticerci of this species,
two adult and six young Tenia expansa, a quantity of young aud old Strongylus con-
tortus, and a few specimens of Trichocephalus.

October 16.—A buck lamb, another of flosix, was found to be infested by a quantity
of very young tenia, also by young and old Strongylus contortus, Dochmius, and Tri-
chocephalus.

October 17.—Another of the six animals bought in May was found to contain young
and adult Tenia expansa, Strongylus contortus, Dochmius, and Trichocephalus.

January 3, 1389.—A lamb slanghtered for examination was found to contain three
Tenia expansa, one Cysticercus, and many specimens of Strongylus filicollis.

The period which had elapsed from the time that these lambs had been
received on the place, to the period when the majority were examined
(from May to October), was about five months. Those first killed gave
negative results, probably because they were examined too soon after
feeding. ‘The lot examined in October gave very positive results.
The worms found in them varied from very young to adult. Thesmail-
est and youngest are those shown on Plate XV, figs. 8,9,and 10. These
were not fed to the sheep, for lambs which had not been fed were in-
fected ; but the majority of the young tape-worms were acquired and
developed after the sheep came under the experiment. This is amply
proven in the case of the young buck bought and put with its mother in
the experimental yard before the former was two days old. That the
time of development of the adult worm is less than four months was also
proven, from the fact that other lambs, less than four months old, ex-
amined in May at the slaughter house, contained aduit tape-worms.
The lambs, therefore, acquired those parasites on the place. The ques-
tion of the necessity of an intermediary host is also settled by this ex-
periment, for none of those invertebrates, which are usually suggested
as being the intermediary bearer, were present at any time; nor were
the conditions which are essential to the life of many such invertebrate
hosts present. The pasture was and is a very dry hillside yard, from
which the grass was eaten very close by the sheep.

‘There is another phase of the question which is still in doubt. Barly
118

in the experiment segments of tape-worms were placed in an iron trough
out of which the sheep drank, or could have drunk. all summer long;
and there might have been times when, for a day or two, alittle puddle
of water could have collected after a rain. In these, more especially
the former, the development of the parasites could have proceeded
until they were taken up by the lambs. The poiut in doubt is, whether
the lambs got their embryos from the water or from the yard while
grazing. Iam inclined to believe the latter, for they acquired other
species of worms which were not placed in the iron tank, and these were
also in various stages of development. Still another feature inclines
me to this view. If the lambs had been infected from the iron tank
they would very likely have been infected by a large number of tenia,
all of nearly equal size; but they were not. Direct infection has been
tried before, but only negative evidence obtained. The failures prob-—
ably arose not only from expecting results too soon, but also from not
preparing the infecting material properly.

Since writing the above, two lambs. have been examined, which give
additional data:

August 10, 1889.—A five months old lamb was examined, which had been born at
the experimental station, and kept there under the same conditions as the other
lambs, i. e., water supplied from a pump and pasturage from the yard and lane near
the sheep peus. This lamb contained two adult Teniae, and Strongylus contortus, S.
filicollis, S. ventricosus, Dochmius cernuus, Trichocephalus affinis, and Usophagostoma
Columbianum, in all stages of growth. ‘The last species did not show adults.

August 10.—Examined a lamb eleven weeks old, which had been bought with its
mother from a neighboring slanghter house when two days old. The lamb had been
kept under the same conditions as above. There were found one adult Lenia (shed-
ding proglottides carrying well-developed six-hooked embryos) and all the other
species enumerated above, but not in the same abundance. Each of these lambs
showed that the infection had been continuous. The elder of the two yielded a
greater number of S. filicollis than any sheep hitherto killed, and led me to think
that this species may have been productive of more trouble than had hitherto been
suspected.

The above experiments were planned with an aim to obtain infection
within a limited area, and under conditions which could be controlled,
deeming it better to obtain infection under such conditions, though
there be a number of them to complicate the question, than to restrict
the conditions and not get an infection.

The presence of the adult tenia in the comparatively young lamb of
eleven weeks shortens the limit of time of complete development of the
tenia, The tenia was about two yards long, and had developed inside
of three months. A reason for the early infection of this lamb was that
its mother died and left it to shift for itself. These experiments con-
clude the series for determining whether sheep necessarily get the worms
from drinking water or from the pasturage.

Summary.—The life history seems from the above to be a compara-
tively simple affair. The embryos pass from sheep to sheep and develop
into adults, which reproduce young for infection of other animals.
119

Whatever changes the embryos may pass through outside the sheep
can have little to do with the case as far as a knowledge of prevention
ot infection goes, for but very few of the conditions under which these
sheep were kept can be improved by the flock-master.

Disease.—The tape-worm disease can be diagnosed by finding the lit-
tle white oblong tape-worm segments which are voided from the sheep
and stick to the moist pellets of dung. They may also be found adher-
ing to the wool and dirt around the tail. But this is only after the
tape-worms have become adult and have begun to shed segments.
Though sheep often harbor tape-worms and give no evidence of their
presence until after slaughter, there are other cases in which their pres-
ence is only too evident to the flock-master. The first indications of
the disease are usually unobserved, because of the slow growth and of
the comparatively small number of parasites that may be developing,
The time of growth occupies about two or three months from infection.
The number of individuals may be from two or three to a hundred, but it
is unusual to find more than a halfdozen adults together. As many as
fourteen adults were found in a lamb four months old. When young
they occupy but small space, need little food, and cause few vermicular
contractions. In the earlier stages it is plain that they cause but little
trouble, but when they grow so large that they seem to fill the whole of
the small intestines they cause the serious disturbances ascribed to them.
These disturbances may be to a certain extent those arising from a re-
flex irritation of the sympathetic and spinal nerves, but most of them
seein to be due to the indigestion which the worms produce. The worms
obstruet the intestinal canal by their great mass, irritate it by their ver-
micular contractions, cause excessive secretion of intestinal fluids, non-
assimilation of food, and abstract nutriment from the intestinal con-
tents for their own growth.

The Jambs become poor and hide-bound; their flanks may either be
distended by gas in the bowels or be tucked up from gauntness.
In the progress of the disease the animals become evideutly weaker,
the mucous membranes paler, and the fleece dry and harsh from the
loss of its yolk. The animals walk with a tottering gait. They often
eat more and drink oftener than those less affected. In the severest
cases the lambs grow extremely weak and poor, diarrhea becomes more
and more pronounced, and at last they die through sheer exhaustion.
While suffering from these worms they are more susceptible to the at-
tacks of other parasites, and other diseases supervene and hasten the
death of the already weakened animals.

Prognosis.—Though the tape-worm disease in its mildest’ form is very
destructive to lambs and yearlings, yet it would seem that if they are
able to pass safely through a certain period they are very apt to re-
cover. In 1887, in the examination of two wethers which two weeks
before had been passing proglottides, or segments, in abundance, and
120

from which it was expected to secure specimens for illustration, only
a sinall piece of the worm was found, all the rest having passed away.

Occurrence of the diseuse.—The worm, though present throughout the
year, is more abundant in the locality of Washington during May and
June than at any other season. This fact was doubtless somewhat de-
pendent on the age of the lambs examined, which were about three or
four months old at that time. In Colorado an outbreak was heard of
in a flock of Merinos which occurred annually about July and August,
after which time the lambs wouldimprove. The disease is more prev-
alent in the summer season, and causes the greatest damage in lambs
less than six months old. If the young animals can be carried beyond
this age they seem to be either better able to withstand the ravages of
the parasite, or to have reached a season unfavorable for its develop-
ment. °

Duration.—The broad tape-worms do not last long in theiradult state,
but after maturing nearly all their segments are shed at once. Trom
the time that the segments are shed the afflicted lambs will begin to
receive and rapidly lay on fat. The disease leaves no traces other than
debility in the early stages of recovery.

Preventive treatment.—Treatment for the prevention of this disease is
that suggested for general prevention of parasites and an observance
of those measures which promote good health in the flock. Do not
overstock pastures. Give good, pure water. When possible, put the
lambs on new pastures. Feed some grain, put salt where the animals
can take it daily, feed hay from racks, and grains, salt, and water from
troughs.

“The medical treatment promises better results than that for Tenia
fimbriata, since the T. expansa is never found wedged into the gall duet
cr pancreatic duct, as is T. fimbriata, but is found lower down in the
small intestine, from whence it can be removed. Many of the popular
tape-worm remedies are said to be efficacious, butas the disease is dif-
ficult to diagnose until the worms begin to shed their segments much
damage is done to the heaith of the lambs beforetreatment begins. On
those farms and ranches wliere it appears periodically the lambs should
be treated as soon as they begin to show symptoms. Even then com-
plete cure can not be attained, for the lambs will continue to pick up
eggs as in the first instance. For safety all sheep in the flock should
be dosed, especially if all are to occupy the same pastures as those
affected.

Ziirn (Die Schmarotzer, ete., p. 191, 1882), says that treatment is
practical when the disease is recognized before the lambs and yearlings
are reduced to a cachectic condition. Although those far reduced in
strength may not survive a medication, still they should be dosed in
order that the parasites may be expelled. Otherwise the sick not treated
should be yarded by themselves or killed and buried, so that they may
not scatter eggs for further infection. Before giving the sheep any
121

worm remedies they should be prepared by withholding food the night
before and not watered on the morning of treatment. The dose should
be administered at one time, allowing every animal to swallow it slowly
if fluids are given. They should not be turned out after dosing, but
should be watched during the day to sce if the worms are voided. If
the worms are not passed off the dose should be followed by a cathartic
on the next day. If it is certain that the sheep have tape-worms and
none appear, the animals should be redosed with increased quantities
on the following day. Of course particular attention must be paid to
the purity of the drug given.

After the sheep have been driven out the yard should be cleansed hy
removing the surface earth. This dirt should be placed where it can
not be washed on to the grass to which the sheep have access; or, it may
be thoroughly disinfected, burned, or buried. Cleansing the yard may
save a reinfection.

Ziirn (0. ¢, p. 192) details experiments made by Schwalenberg, in
which wormseed, Persian insect powder, petroleum, Chabert’s oil, ka-
mala, kousso, and koussin were tried. The last three gave good results.
In the first experiment 3.75 grams kamala (about 1 dram) were given to
each lamb. This dose caused diarrhea and removal of the tape-worms
in forty-eight hours. The lambs-remained poor for a long time, in spite
of good care.

In the second experiment 7.50 grams kousso (nearly 2 drams) given
each lamb gave good results.

Koussin, also known as teniin or brayerin, in 12 centigram or 2-grain

doses, gave better results. The tape-worms wereexpelled. The treated
animals remained cheerful, retained their appetites, and improved in
condition.
. Picric acid, 10 to 20 grains, made with meal and water into a pill, is
also recommended for lambs. This quantity is sufficient for one dose,
and should be followed by a cathartic. Epsom salts in 4-ounce doses
is a good saline cathartic, or 4-ounce doses of the bland oils, adminis-
tered slowly, may be-used. ,

The powdered male-fern root, in 2-ounce doses, is recommended, or
the etheric oil of male-fern in dram doses. The latter is the best. It
can be given in combination with from 2 to 4 ounces of castor oil. Dr.
H. Piitz (Seuchen und Herde Krankheiten) recommends dosing in the
morning, and withholding all food the night before giving the medicine,
and on the following morning to give a cathartic. This may be unneces-
sary, however, when the male-fern has been given with castor oil.

Frébuer (Thierdrztliche Arzneimittellehre, 1889), gives the following
recipes for lambs with tape-worms: Take of koussin 3 grains, and of
sugar 10 grains, mix, and give at one dose. The dose of tansy is from _
2to6.drams. It forms one of the chief ingredients of Spinola’s worm
cake, which is fed to lambs as a preventive medicine against worms,
The recipe, sufticient for one hundred sheep, is as follows: Take of
122

tansy, calamus root, ani tar each 24 pounds; of cooking-salt, 14 pounds;
mix these with water and meal, make into cakes, and dry. This is an
old and oft-repeated recipe, but I can not vouch for its efficiency.

Powdered areca nut may be given to lambs in from 1 to 3 dram doses.
If it does not produce a stool in three or four hours it should be fol-
lowed by a cathartic.

Ground pumpkin seeds are in repute with some, but it is difficult to
indnee sheep to eat the required dose.

Tellor (Diseases of Live Stock, 1879, p. 383) recommends salting liber-
ally, and giving once a week the following saline tonic and bitter-lick
as a preventive against worms: Take of common salt 2 pounds, sul-
phate of magnesia 1 pound, sulphate of iron and powdered gentian,
each half a pound, and mix with ground feed or fodder sufficient for
seventy-five to one hundred sheep. This recipe is a very satisfactory
one for improving the appetite and bealth of the sheep, but probably
can not be depended on for keeping the worms away.

For tape-worm in sheep the same author recommends: Powdered
areca nut, one-half to 1 dram; oil of male-fern, 10 to 20 drops; give in
molasses and water, and follow the next day with a purge. For purges
he gives two recipes: Sulphate of magnesia, 2 ounces; warmwater, 1
pint in one drench; or, castor oil, 3 ounces; calomel, 12 grains; mo-—
lasses, 3 ounces—for one dose.

After the sick lambs have been treated, care and attention should
not be relaxed, for it is of the utmost importance that they regain their
strength-and vigor before the cold ‘weather sets in. The best pasture,
an extra feeding of hay, and some roots and grain in judicious quanti-
ties, should be allowed them. ‘he feeblest should be kept by them-
seives, where they can get plenty of food and water without entering
into competition with the stronger. This treatment should be kept up
until they are fully able to hold their own.
124

TANIA EXPANSA, Rud.

PLATE XIV.

Figs. 1 and 2. Young tape-worms, natnral size.

Fig.
Fig.
Fig.
Fig.

Fig.
Fig.

3.
4.

5.
6.

7.
8.

Head end of tape-worm, drawn to show vermicular contractions when living.

Head, top view: a, a, the suckers or cups, by which the worm attaches
itself to the intestinal walls.

Head, side view: a, a, suckers ; b, b, folds in the neck; c, c, the first segments.

The large end of a young tape-worm: a, a, segments which are not mature
enough to drop off; b,b, segments ready to pass away from the worm.

Segments, or proglottides found, separate from the worm.

An adult tape-worm, drawn in sections at regular intervals apart: a, head.

Fig. 9. A fragment of another worm, which is not only slightly larger, but whose

segments are shorter and broader.

The specimen shown in fig. 8 could have assumed very much the same form when

alive as is seen in fig. 9.
PLATE XIV

 

ey ee apg

idl

 
 

 

 

 

 

 

 

 

 

Boltimere

A.Hoen & Co. Lith

Geo. Marx, del.

TAENIA EXPANSA,
(The Broad Tape-Worm.)
Fig.
Fig.

n

7.

8.
9.

Fig. 10

126

TANIA EXPANSA EMBRYOS.

PLATE XV.

. Embryos magnilied and flattened under cover-glass.

. Asingle embryo and its enveiopes somewhat flattened.

. The same greatly flattened: a, the thick, oily mass between the inner and

outer covering,

. The same with outer envelope ruptured: a, the outer envelope; 0, the in-

ner ;

; ¢, oil globules; d, the embryo and its pyriform apparatus.

. Embryo, with three envelopes.
. Embryo escaped from ruptured inner coat: a, the fringed cap-like covering;

b, the bladder-like sac protuding from it; ¢, the six-hooked embryo.

A younger embryo, inwhich the bladder portion has not burst from the cap;
a, the cap; b, the embryo.

Three young tenia which show no trace of segmentation.

A young tenia which is beginning to segment.

. A head of young specimen showing a peculiar loop in it.
PLATE ‘XV

 

= A.Hoen & Co, Lith, Baltimore,
Geo. Marx, del. TAENIA EXPANSA
(Young Stages.)
THE LIVER FLUKE—LIVER-ROT.

DISTOMA HEPATICUM, Linn.

Plate XVI.

The liver fluke disease, which causes so much loss in Great Brit-
ain and on the European continent; is comparatively unknown in this
country ; so rarely, indeed, is it discovered that most authorities on the
management and care of sheep seem never to have seen it. That it
has occurred in this country, and that it is present in certain portions
of it, is tolerably certain, for good observers have recorded it at various
times.

Henry Stewart, in the Shepherd’s Manual, 1882, page 223, says that
flukes were found in a flock of Southdowns at Babylon, Long Isiand,
and also in Cotswold, Leicester, and native sheep, presumably at the
same place. In the Tenth Census Reports of the United States, Vol. IIT,
flukes are said to occur in Texas and California. In the latter State
they have been seen by Prof. E. C. Stearnes, of the Smi!hsonian Insti- ©
tution.

‘The disease occurs so infrequently in this country that the writer has .
seen but two cases of it, and both of these were in cattle. For a de
scription of the malady we will therefore have to depend upon writers
in those countries where it occurs more frequently than it does here.

-Description.—Body flattened, leaf-like, pale brown, irregular, the adult from 18
to 31™™ long, from 4 to 13™™ wide, oblong, oval or lanceolate, larger and rounder in
front, where itis abruptly contracted in such a way as to present 1 conical neck;
attenuate and obtuse behind. Skin bristling with numerous little points directed
backward. Oral sucker terminal, rounded. Ventralsucker large, projecting, with a
triangular opening situated about 3™™ behind the first. Intestine with two rami-
fied branches visible through the skin and of a deep shade. Penis projecting in
front of the abdominal sucker, always recurved. Vulva very sinall, situated at the
side of the male orifice or a little behind. Eggs brown or greenish, ovoid; length
from 0.130 to 0.145™™; width from 0.070 to 0.090™™, (Neumann.)

Occurrence.—This parasite has been found in the livers of sheep,
goats, cattle, camels, and certain wild ruminants. It has also been
found in the horse, ass, pig, elephant, rabbit, and man. It lives in the
biliary ducts of the liver, and, according to Kiichenmeister, feeds on
blood drawn from the mucous membranes of those passages. The par-
asite does not appear to be equally abundant at all times in Europe,
but seems to develop at various periods in sufficient numbers to cause
epizootics. A number of these outbreaks, compiled by Neumann, 0. ¢., p.

y : 127
128

463, demonstrate no periodicity or law by which future outbreaks may
be suspected or predicted.

Sheep-owners and veterinarians are agreed that damp, wet seasons,
and damp pastures are favoring conditions for the development of the
parasite and promotion of the disease.

The life history of the parasite has been determined by Leuckart in
Germany, and a little later, but apparently independently, by A. P.
Thomas, in England. The former published his observations in Zoolo-
gischer Anzeiger, December 12, 1881, and October 9, 1882, and the lat-
ter in the Journal of the Royal Agricultural Society of England, Vol.
XVIII, part 2, 1882, and Vol. XIX, parts 1 and 2, 1883, These authors
have described most of the stages in the life history of the parasite,
leaving but little to be said in addition.

The egg of the fluke passes from the biliary passages through the in-
testine to the ground (Plate XVJ, Fig. 2a). Those that fall in favorable
places develop (Fig. 2b) and finally break the little lid off the end of
the shell (Fig. 2c) and escape. This happens in summer and occupies
from three to six weeks. .At this stage (Fig. 3) the whole body is covered
with fine cilia (hairs), which enable the embryo to swim about in the
water. At one end of the embryo is alittle projection which can be
thrust out and withdrawn, and isthe apparatus by which it bores into
its second host. If it does not meet one in a day or two it dies. If it
meets a water snail (I'ig. 6 and 6a), it is not slow to penetrate into the
body, where, according to Leugkart, it lodgesin the respiratory cavity.
Here it encysts itself (Fig. 4), contracts into an oval mass, and rapidly
grows. The name sporocyst has been applied to this form. The con-
tents of this sporocyst split up into a number of bodies (Fig. 4), usually
from five to eight, which develop into redie (Fig. 7). Their length
at this stage is about 2", or one twelfth of an inch. These are ex-
cluded from the sac one by one through a rent. Now each redia, in
its turn, develops from fifteen to twenty cercarie (Fig. 8) within it, which
are evacuated in turn through an unpaired orifice situated under the
neck of the redia. The cercariz are the forms that escape from the
snail, and are scattered by it in its wanderings. The cercaria, aftera —
time of active life, loses its tail, which it has developed, and again en-
cysts itself. (See Figs. 11 and 12 and Fig. 10.) The contents of the
cyst still more resemble the future fluke, aud itis at this stage that
the sheep swallows it with grass. Itthen breaks from the cyst, arrives
at the stomach and duodenum, to finally make its way into the biliary
canals aud grow into another adult hermaphrodite, capable of giving
rise to other generations of young.

According to Thomas the encysted embryo (Tig. 4) may give rise to
daughter rediz or to cerearic, the former to develop in the summer and
the latter during the cold season.

The epitomized life history is first the egg; second, the embryo, which
encysts in a snail; third, five to eight rediz, deyeloping from the eystia
129

larva; fourth, fifteen to twenty cercarie, developing trom each redia
and escaping from the snail; fifth, the encysted cereariz, which after
havivg been swallowed by a lamb develop into adult flukes.

This life history is fully as wonderful as any occuring in nature. Ac.
cordiug to it, at least seventy-five young flukes under favorable sur-
roundings could develop from a single egg. As the proper conditions
are scarcely ever fulfilled, there are but few of those which meet with
all the requirements for development.

The disease created by these peculiar parasites is known by many
names, the most popular of which is Liver Rot, a term expressive of the
chief pathologic symptom. Aqueous Cachexia, Rot, Rot Dropsy, Sheep-
~ Rot, Liver-Disease, Liver Fluke, Jaundice, Yellows, Verminous Phthisis
of the Liver and Ictero-Verminous Cachexia, are other names for the
disease, each being expressive of some of its symptoms.

The symptoms, according to Neumann (Maladies Parasitaires), to whom
the writer is indebted for the greater part of this article, may be divided
into four periods, viz:

(1) Period of immigration.—This is the period in which the parasite
invades the liver. In this stage the flukes are small and do not cause
excessive disturbances. This period lasts from four to thirteen weeks.
It is probable. that it lasts as long as the weather remains favorable
for the development of young flukes aud sheep are kept on infested
pastures.

(2) Period of anemia.—This ordinarily coincides with the months of
November and January, or after the lapse of thirteen weeks from infec-
tion. The sheep are less lively; the mucous membranes about the eyes,
the nose, and the guins, the internal surface of the ears and the skin, are
all paler than in well sheep. The appetite is still good, and the animals
have a tendency to fatten, caused, according to Simonds, by a better
assimilation of food from the increased flow of bile stimulated by the
young flukes. This fattening stage has been taken advantage of in
England by a dealer (Bakewell), who purposely exposed the lambs he
wished to market early to the disease, that he might send fat lambs into
the market five or six weeks ahead of his neighbors. Sometimes the
appetite diminishes, thirst increases, and rumination is irregular. The
conjunctiva, the mucous membranes of nose and mouth, and the skin
are white, slightly tinged with yellow. There is a slight cedema (puf-
finess); the skin is looser, feels pasty and soft to the touch where bare;
the conjunctiva is infiltrated and puffy and the eye partially closed ;
the wool becomes dry and brittle, is easily puffed off, and sometimes
falls off of itself. Weakness appears more and more marked. There
is sometimes fever and quickened breathing. Palpation and percussion
indicate ascites. The droppings are normal, but contain at the end of
this period numerous fluke eggs. Death may result in this stage from
_ apoplexy.

23038 A P-—9
130

(3). Period of loss of flesh.—The sheep begin to become leaner at the
end of the third month after the immigration of the larvae, or about
the beginning of January. The malady is then at its height. The
animal becomes gradually leaner; the mucous membranes and the skin .
are bleached, and lose the yellow tinge. The temperature is variable
and is highest in either the morning or evening. Respiration is feeble
and frequent. The appetite keeps up, and the feces present nothing
in particular except fluke eggs. The urine is nearly normal. The ani-
mals are listless and dejected, carry their heads iow, and give way when
pressed on their backs. There are frequent abortions. Nursing ewes
have a clear, watery milk, very poor in nutritiveelements. _Their lambs
are weak and thin, and usually die unless they are put to another nurse.
The edema becomes localized and increased in dependent parts. It is
dispelled by walking and comes again in rest. The space under the
jaws and along the trachea is a frequent seat of puffiness. This disap-
pears during rest and comes on during feeding. It is often absent
with adults in hot seasons. In the three weeks which follow the ani-
mals become still poorer dlespite abundant feeding, and there is gener
aliy diarrhea, cedema, jaundice, and pain on pressure over the liver.
Either death occurs at this period, or the animals improve and enter the
next period.

(4) Period of emigration of the flukes.—This is the period of convales-
cence and of spontaneous cure. All the symptoms grow less and finally
disappear, but the cureis never complete, the changes which have taken
place being irreparable. The recovery of affected sheep is exceptional.

Duration of disease.—The flukes are said by some authors to remain
nine months in the liver, by others fifteen months. After this time they
make their way into the intestine and are evacuated with the excre-
ments.

Thomas says that he has seen the sickness last six years, and Neu-
mann seems to coincide with Perroncito, that the flukes have little ten-
dency to quit their hosts. The question of reinfection of the same ani-
mal would leave it doubtful whether such long period of infection were
all due to the same parasites or to renewed generations of them. |

The duration of the disease, which, as a rule, is variable, depends en-
tirely on the degree of infection and the treatment, hygienic and me-
dicinal, which they receive. It ordinarily lasts about six months, but
exceptionally may have an extremely rapid course of a few days, death
being caused by an acute inflammation of the liver, set up by the para-
sites, and occurring in from seven to nine days after the first appear-
ance of the disease. Weakened by the fluke disease, the animals are
more susceptible to other maladies, and these may destroy them before
the primary disease has run its course.

Diagnosis.—There. is little difficulty in diagnosing liver-rot in the
stages at which it is first noticed if the flock-master sacrifices one of the
worst affected sheep. Although he may think that it hardly pays to
131

kill a sheep to find out what the trouble is, he will subsequently learn
that a little loss in the beginning leads to a great saving in the end, and
therefore becomes an investment. _

In fluke disease not one or two lambs only are infected, but all the
flock that have been feeding together. If the flock-master has a micro-
scope he can detect eggs of the fluke in the droppings, but this can only
be found after the fluke has matured and the disease has well advanced.
Besides, it requires some skill to make the required examination. So
numerous are the eggs and so characteristic is the shell with its little
cap, however, that this method forms au important element in diagno-
sis. The droppings should be moistened with water and thoroughly
picked to pieces, then spread evenly on a piece of glass and covered by
another thin glass. The mass shon!d be closely examined with the aid
of a microscope magnifying from 70 to 80 diameters. This operation
should be repeated a number of times if eggs are not found. The ex-
amination of the liver is the best means of diagnosis. When the gall
ducts are cut open the young flukes will be found in them. They usu-
ally occur in smaller or larger nodular swellings. The structure of the
liver is also characteristic, presenting a dark, soft, rotten appearance.
Young flukes can be found by cutting into this organ and washing it in
water. After allowing everything to settle, pour off the top and repeat
the operation until the contents of the dish can be distinguished. When
spread out on a flat-bottomid dish the flukes may be easily distinguished
by the unaided eye, or, if very young, by the help of a small lens. If
the sheep has been killed the tiukes will be seen to wriggle and curl,
for they die slowly in water ordinarily warm.

Prognosis.—The disease is very tenacious, and when once on a farm
is difficult to extirpate. Many farms in infected localities are rendered
useless for sheep raising by these parasites. When a flock becomes
infected it is not to be expected that the disease will be stopped until
it has caused extensive damage, and that only the most prompt and
effective measures will save any of the afflicted animals.

Pathology.—The disease is seated in the liver, and all the symptoms
and changes observed in other parts are directly dependent on those
occurring in this most important organ. The different periods into
which the various alterations have been divided are directly dependent
on the periods in the life history of the flakes. For our present purpose,
however, it seems advisable to give but the most brief description of
these pathologic changes.

When the flukes first invade the liver they cause an inflammation,
which is shown by a thickening of its mass. It becomes softer, and
the surface, which should be smooth and glistening, becomes rough.
These changes increase as the days go by, and the liver becomes softer '
and thicker. The surface becomes covered by thready fibers, as well
as much rougher; the abdomen contains more or less dark-colored
serous fluid; young flukes from one-tenth to éne-fifth of an inch long
132

can either be found in serum-filled cavities of the liver or attached to
the outside, or perhaps free in the cavity. Still later, the liver shows
places puckered up, which are caused by the reparative process and the
contraction of the newly-formed tissue. There will be numerous chan-
nels beneath the serous membrane visible to the unaided eye. The bil-
iary canals will be found thickened and enlarged at places to the size
of a hazel-nut, or even larger. In these dilatations are flukes of con-
siderable size, surrounded by a greenish black, sticky mass. Some-
times hard limy fragments are found in them. The substance of the
liver becomes very rotten, and crackles under pressure by the finger.
When the flukes migrate healing takes place to some degree, but the
liver will never Jook healthy. It will grow considerably smaller and
become much whiter, due to the connective tissue changes which take
place.

Preventive treatment.—Thomas has formulated rules of prevention
against this parasite, which are founded on its life history and seem to
be eminently practical. He says: :

(1) All eggs of the liver fluke must be rigorously destroyed. Manure of rotten
sheep or other infected animals must not be put on wet ground. As the liver and
intestines contain eggs, these, too, must be destroyed or put in the compost heap.
The manure of affected animals should not be stored where there is a drainage from it
to the neighboring grass. It should be mixed with lime and salt before being spread
on meadows or cultivated fields.

(2.) If sheep are infected, let them be sent to the butcher at once, unless they are
specially valuable and are not badly affected. If. kept, they must not be put onto
wet ground,

The above advice is preferable with all common stock; and the ex-
ceptions, when medicine should be tried, are very few. Stock should
be very valuable to repay the expense of care and treatment in face of
the large percentage of death which occurs in this disease, and the ill
condition of the remnant after recovery.

(3.) Care must be taken to avoid introducing eggs of the fluke either with manure .
or fluked sheep, or in any other way. Rabbits and hares must not be allowed to in-
troduce the eggs.

The most prolific source of introducing parasites is in the introduc.
tion of infected sheep, and purchasers should learn all they can of the
history of the animals they buy, and not purchase from diseased flocks.

(4.) All heavy and wet ground must be thoroughly drained. /

Draining is of advantage in many ways. It wakes tillable land of
what was before useless, either for pasturage (as shown by its infecting
the flocks with a fatal disease) or for cultivation.

(5.) Dressings of lime and salt (or both) should be spread over the ground at the
proper season to destroy the embryos, the cysts of the fluke, and also the snail which
‘acts as host. ;

After draining, such fields should be cultivated and suitable crops
raised on them.

(6.) Sheep must not be allowed to graze closely, for the more closely they graze the
more fluke-germs will they pick up.
133

This rule is advisable wherever the sheep may pasture. Sheep on
over-stocked pastures do not get enough grass, and become more in-
fested with worms from having to eat close to the dirt.

(7.) When sheep are allowed to graze on dangerous ground they should have a daily
allowance of salt and a little dry food.

Exigencies can be conceived in which sheep may be allowed to pas-
ture on infected ground, buat, in view of the fatality attending the
malady, it would seem more profitable to sell the animals while they are
still in good condition than to expose them further to these parasites.

Lime and salt are the two cheap preventives against this parasite.
The former, mixed with manure, increases its value as a fertilizer. A
solution of three-fourths of 1 per cent. of salt in water has been found
by experiments in the laboratory to kill fluke embryos. This weak so-
lution might prove too weak in the field, when the salt would be still
further diluted by dew or rain. Perroncito has shown that the encysted
cercariz and the larve encysted in Limnea palustris die in 2 per cent.
salt solutions in five minutes; in 1 per cent. solutions they die after
twenty or thirty-five minutes; 0.65 per cent. solutions kill in about the
same time; in 0.25 per cent. solutions the worms live after twenty
hours’ immersion.

The weakness of the brine necessary to kill the parasites in the labo-
ratory points out that a small proportion of salt mixed with the lime
would be very advisable. Salt was first advised from a knowledge of
the fact that sheep never became infected with flukes on salt marshes.
Stronger solutions of salt also kill the snails, which are the hosts of the
embryonic fluke.

The time of year for scattering the lime or salt on the fields is the
first part of June, July, and August.

Neumann advises mixing two teaspoonfuls of salt for each sheep
with the ground grain they eat. Perroncito advises the addition of
one-balf of 1 per cent. salt to the water they drink (about a heaping
tablespoonful to each gallon of water).

Aithough the flockmaster can never completely cure his sheep, he
may, by judicious medication, so improve the condition of the con-
valescent animals that they will take on considerable flesh. Many
vegetable astringents and tonics have been tried, with more or less
profit, but it is to the mineral astringents that we foul for the best re-
sults. Sulphate of iron and common salt, dissolved in the drink or
mixed with the food, are among the best ane cheapest.

Medicinal treatment.~Some experimenters have endeavored to kill
the flukes, and have met with varying success. The remedies tried
have been extract of male-fern, given with turpentine or benzine, castor
oil, etc. For proportions of these remedies see remedies for Tenia ew.
pansa. Mojkowski, according to Neumann, has obtained encouraging
results against the distomatosis (the fluke disease) of sheep with naph-
134

thaline, given twice a day during a week, in from 10 to 15 grain doses,
alone, or mixed with powdered gentian.

The following recipes, to be used as licks, may be useful in small
flocks:

Take of sulphate of iron, 2 ounces; calamus root, 1 pound ; of crushed
oats and roasted barley malt, of each, 20 quarts. This quantity is
sufficient for one hundred sheep. Other mixed grain may be substi-
tuted for the barley-malt and oats. Or, sulphate of iron, 1 ounce, and
powdered juniper berries and gentian root, of each, 1 pound. Mix
with 20 quarts of grits. <A lick for fifty sheep.

A very complicated but apparently good tonic remedy is known as
Spinola’s worm-cake, see page 121. Vieth recommends the following:
Oak bark, calamus, gentian root, and juniper berries, of each 2 pounds.
Pulverize and add pulverized sulphate ofiron, 1 pound; pulverized cook-
ing-salt, 10 pounds. Mix thoroughly, and give each sheep a teaspoonful
every two or three days. The medicine is most easily administered
mixed with meal, chops, bran, etc. Hither of the vegetable ingredients
of the above recipes can be omitted and substituted by some other well-
known tonics, though each is thought to have its special virtues. The
dietary treatment is the most valuable. Grain-feeding, mashes, strong
meals, as flax seed meal cakes, or cotton-seed oil cakes, can be given in
judicious quantities. The general treatment should embrace every
means known to the flock-master to sustain the, health of the flock.

Police sanitation.—The meat of sheep affected with liver-rot is safe to
eat, but in advanced stages of the disease it is too watery, lean, and in-
nutritious to be wholesome food, and is only an inferior article. When
killed during the early stages of the disease it is more salable and nutri-
tious. Later on, it should not be put on the market or received by -
buyers.
g.
Fig.
Fig.
Fig.

—

on

10.
11.
12.
13.

136

DISTOMA HEPATICUM, Linn.

PLATE XVI.

. Adult fluke, natural size: la, young fluke, natural size. (Raillet.)
. Eggs: a, egg with developing embryo; b, egg with embryo; ¢, egg-shell.

(Raillet.) -

. Ciliated and free embryo: a, perforating apparatus ; }, ocular spot. (Leuck-

art.)

. Encysted embryo found in snails. (A. P. Thomas.)
. Diagram of digestive apparatus and nervous system: a, mouth sucker; 8,

pharynx; ¢, esophagus; d, branches of intestine; e, their branchlets ;
Jf, nerve ganglia; g, ventralnerve. (Raillet.)

. Limneus truncatulus, the principal snail which is the larval host of the fluke

in Europe: a, natural size. (Raillet.)

. Redia of Distoma hepaticum: a, mouth; b, pharynx; ¢, digestive tube; d,

the so-called germinative cells destined to produce cercaria. (Lenckart.)

. Redia containing cercarie: a, mouth; b, pharynx; c, digestive tube; d, d,

cerearie. (Leuckart.)

. Cercaria dissected from its cyst: a, anterior sucker; b, ventral sucker; c¢,

pharynx; dd, branches of the intestine terminating in ceca. (Leuckart.)
Grass stalk with three encysted young flukes, a,a. (A. P. Thomas.)

Free-swimming cercaria just before it is about to encyst. (A. P. Thomas.)

A slightly older stage than Fig. 11. (A. P. Thomas.)

Genital apparatus of the liver fluke: a, digestive tube; 6, ventral sucker;
c, anterior testicle; d, its deferent canal; e, posterior testicle; jf, its def-
erent canal; g, seminal veside; h, genital sinus; i, cirrhus pouch; j,
ovary; k, oviduct; 1, shell-gland; m, yolk glands; n, longitudinal and
o, transverse yolk-gland canals; p, uterus; g, vagina. (Raillet.)
PLATE XVI

at as

 

Baltimore

Lith

A.Hoen & Co,

DISTONIA HEPATICUM

(The Liver Fluke.)
137

DISTOMA LANCEOLATUM, Mehlis.

Plate XVII, Figs. 11 to 15.

Description.—Body semi-transparent, spotted with brown by the eggs, length from
4 to 9™™, width 2.5™™, lanceolate, obtuse behind, attenuate forward, and terminated
by the oral sucker, which is nearly as large as the ventral. Integument smooth,
intestine with two branches, not further subdivided. Penislong, generally straight.
Genital orifices very close to one another. Eggs ovoid, length from 0.037 to 0,040™™,
(Neumann. ) . /

The life history of this parasite seems to be as yet unknown, but it is
believed to be analogous to that of. Distoma hepaticum. The embryo
(Fig. 11) differs from that of D. hepaticum in being globular, armed with
a cephalic spur, and in being ciliated only over the anterior third of the
body. Its movements are said to be slower.

Ercolani has shown that young embryos measuring 1™ first show
traces of a digestive system (Fig. 14), and that the digestive system is
preceded by groupings of cells, which first outline the testicles, then the
penis, and lastly the ovaries. Two species of suails, Planorbis margi-
natus and Helix carthusina, which contained cercariz, have been pointed
out, the former by Willemoes-Suhm and the latter by Piana as the in-
termediary hosts of the fluke.

This species of fluke never produces symptoms or lesions as grave as D. hepaticum,
and can only occasion aqueous cachexia or dropsy. This relative harmlessness is at-
tributed by Leuckart to its small size and the absence of spines on the skin. The two
species are most often found together in the same host. By reason of its minute size,
D. lanceolatum penetrates into the finest biliary canals, where the young D. hepaticum
can not enter. Because the individuals of the former species escape observation on
account of their small size they appear to be fewer in number. Friedberger has ex-
tracted some thousands from the biliary passages by squeezing the liver. They are
also found in great numbers in the gall bladder and in the intestine at the time of
their emigration. (Neumann.)

The means of prevention and treatment are the same for this as for
Distoma hepaticum. Treatment is of more avail.
PARASITES OF THE RUMEN.

‘AMPHISTOMA CONICUM, Zeder.

Plate XVII, Figs. 7 to 10.

Body of a rose tint, irregular, and more or less dark. It is ovoid, narrowed in front,
and swells gradually even to the posterior end; obtuse and slightly recurved on the
ventral face. Length from 10 to 13™™, width behind from 2 to3™™, (Neumann.)

This parasite has been found in sheep in India and Australia. The
author has not observed it in this country. Itoc2urs scattered amongst
the large villi of the rnmen or first stomach, attached by its posterior
sucker. It is said to cause but little digestive disturbance. Figures
and description of this parasite are presented, as it is a representative
of the genus, and may sometime serve for generic determination of
allied parasites which may be found in this country.

138
Fig. 1
Fig. 2
Fig. 3.
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11.
Fig. 12.
Fig. 13.
Fig. 14.
Fig. 15

140

LINGUATULA TZENIOIDES, Rudolphi.

PuaTE XVII.

. Male, natural size. (Cobbold.)
. Female, natural size. (Cobbold.)

Egg with contained embryo. (Leuckart.)

. Embryo escaped from egg-shell. (Leuckart. )
. Pupa nine weeks old: a, anus; b, mouth. (Leuckart.)
. Linguatula denticulatum. (Leuckart.)

AMPHISTOMA CONICUM, Rudolphi.

. Piece of the rumen of a cow, showing the parasite attached between the

papille by their large posterior sucker: a, an isolated individual, natural °
size. (Raillet.)

. Dorsal view, X2. ( Blanchard.)
. Lateral view, <2. (Blanchard.)
. Egg of an amphistoma, x80. (Cobbold.)

DISTOMA LANCEOLATUM, Mehlis.

Ciliated embryo. (Leuckart.)

Early stage of development, in which there is no digestive apparatus.
(Ercolani.)

Another stage: a,a, groups of cells representing the future testicles. (Erco-
lani.) ;

Stage showing the testicles plainer, a,a; b, the rudimentary cirrhus pouch,
and c, the digestive system. (Ercolani.)

5. Adult, natural size figure by itsside: a, pharynx; b, esophagus; ¢, branches

of intestine; d, ventral suckers; e, e, testicles; f, f, deferent canals; g, cir-
rhus pouch; h, ovary; i, albuminous glands; k, uterus; 1, vagina.
PLATE XVII

 

AHocn & Co. Lith Baltimore

LINGUATULA TAENIOIDES. ; AMPHISTOMA CONICUM.
DISTOMA LANCEOLATUM.

Haines, del.
THE STOMACH ROUND WORMS.

STRONGYLUS CONTORTUS, Rud.

Plate XVIII.

Strongylus contortus, or the twisted strongyle, is an inhabitant of the
fourth stomach of sheep and goats. Though in the majority of flocks
it produces but little if any disturbance, yet there are times when, in
- connection with other species, it causes disease which may carry off
numbers of lambs. In the southwestern States and Territories the
disease has been called lombriz, a corruption of the Spanish word lombrici,
meaning worms. The later writers seem to be inclined to attach a
specific meaning to this word, while the Mexicans, who used it, merely
intended to say that the lambs died of worm disease.

Description.—Female, 18 to 30™™ long; male, 15 to 20™™ long; body reddish;
female warked by a double spiral white line, thicker toward the caudal end. The
skin shows eighteen longitudinal lines. The mouth is round and without visible lips
or papilla. The neck has two barb-like side papille; unicellular glands scarcely
visible. The male is about two-thirds as long as the adult female, and shows no
spiral line. Bursa deeply bilobed, with a small dorsal lobe attached to one of the
pair. The lobes are somewhat longer than broad. The ventral cost are separated ;
the lateral are double and separated ; the dorso-lateral is attached to the lateral group
near its base; the dorsal costz support the dorsal lobe and each branch is double;
the twofold character is indicated-by a little notch. The lateral costew are irregu-
larly divided, many variations being observed. Spicula two, embracing a chitinous
piece between them. They are short, cylindrical, barbed on one side uear the end,
and have blunt tips. Female: Vulva 3™™ from the tail and covered by a nipple-
like projection, 0.5™™ long; the latter has thin borders, and is concavo-convex, to fit
the body when pressed against it. Uteri two, each opening into the common vagina ;
one is anteriorly directed and the other posteriorly, with a short loop between it and
the vagina. The ovary of the posterior uterus is reflected anteriorly to rejoin its fel-
low, aud together they wind spirally around the dark-colored intestine. The ovoid
eggs are laid in the gastrula form, or after they have passed through the segmenta-
tion stage; length, 0.070 to 0.097™™; width, 0.043 to 0.054™™,

Occurrence.—This worm may be found in all stages in the fourth
stomach or abomasum of sheep. When collected immediately after
death from a slaughtered sheep they may be detected adhering by their
heads to themucous membrane. They are then of a reddish color, which
may be because they feed in part upon the blood of the victim.

The life history of Strongylus contorlus seems to be apparently simple.
Among a number of lambs kept at the Experimental Station in 1888
were two or three which had been raised there. A post-mortem exami-

141
142

nation of one of these, with four other lambs which had been at the
Station for the five previous months, revealed numbers of Strongylus
contortus in all stages of growth, and of Dochmius cernuus, Trichoceph-
alus afinis and Tenia expansa. These lambs were supplied with well wa-
ter, and were allowed torun in a small, dry, grassy yard connected with
a stable. The presence of these species of all sizes in the former group
of lambs showed that they acquired them on the place, and that their
development was direct; that is, they did not pass through a secondary
host in passing between the sheep and thelambs, for all of the conditions
were under inspection. The grass in the yard became very short, and
probably it was because the sheep ate it so close to {he ground that they
became more infested with worms than sheep ordinarily do. The bis-
tory, therefore, is probably as follows: The eggs fall to the ground;
they are eaten by other sheep along with thetr feed, and they then ar-
rive at the stomach and develop there.

The disease they cause can not easily be distinguished from that pro-
duced by other intestinal parasites. In the worst cases, besides a gen-
eral lack of tone and good health, there is weakuess, paleness, some
fever, diarrhea, etc. In fatal cases death is said to occur within a very
few days after the illness is observed; but, as the parasites develop
slowly, itis probable that no symptoms of illness are apparent until
after the lambs have been ailing for some tiine. A positive diagnosis
is to be made only by a post-mortem examination. The little wornis, if
present in large numbers, will appear like masses of threads lying in
the stomach. If the sheep has been killed for examination, the \ worms
will be seen wriggling and squirming in all directions.

Treatment:—Various remedies are proposed, but of those available
an emulsion of milk and turpentine, prepared by shaking the mass well,
seems most practicable. Add 1 part of spirits of turpentine to 16 parts
of milk, and give from 2 to 4ounces of it to each animal, according to age
of patient. One dose should be sufficient; if not, repeat it in three or
four days. - Or, take of linseed oil, 1 ounce; turpentine, one-half ounce,
shake well and give as onedose. Quantities sufficient for any number
of sheep may be made up in these proportions.

The following recipe is from Finlay Dun’s Veterinary Medicine:
Common salt, 3 pounds; powdered ginger and niter, half pound each ;
dissolved in 3 gallons of warm water; add 24 ounces of turpentine
when nearly cold. The dose for iambs between four and six months’
oldis 2 ounces. The entire quantity is sufficient for one hundred and sixty
lambs. For delicate lambs, which are coughing and purging, the same
writer recommends oil of turpentine, powdered gentian, and Jaudanum,
2 ounces each, all to be dissolved and stirred in 1 quart of linseed tea
or lime water. This quantity is sufficient for ten or twelve doses.

Ziirn recommends (after Rabe) the picrate of potash, because it is
less irritating to the patients. The dose for a lamb is from 24 to 5
grains; for an adult up to 20 grains. It can be given dissolved in
water.
143

Dr. H. J. Detiners, in a report to the Commissioner of Agriculture,
1883, on the diseases of sheep in Texas, recommends the use of tartar
emetic as follows: A half pound of tartar emetic is to be dissolved in
12 quarts of water, and from 1 to 2 ounces of the solution, containing
from 5 to 10 grains of the remedy, is to be given each patient, depend-
iug on its size. He recommends dosing out of a small 2-ounce vial,
and in small swallows.

Good, nourishing food, and a dry yard in summer, or a healthy, well-
ventilated stable in fall and winter, areadvisable. In giving medicine,
drench from a horn, a spoon, ora stout glass bottle. Bottles are always
liable to break. Let an assistant throw the sheep onto its haunches
and hold it between his legs, back toward him. With the lower jaw
seized in his left hand, from the left side, he can either seize the upper
jaw or pull out the cheek-pouch with his right. The medicines are
best administered while the sheep are thirsty. Small doses may be
diluted, but a dose of 4 or 6 ounces is m re apt to run directly into the
fourth stomach than larger doses; otherwise, some of the latter might
be diverted into the second stomach and fail of an immediate effect.

The following recipe was recommended to the readers of Field and
Farm, August 7, 1889, as a preventive remedy for worms in sheep. Mr.
G. B. Bothwell, of Breckenridge, Mo., who used it for fifteen years with
success, is its author.

Salt, 1 bushel; air-slaked lime, 1 peck ; sulphur, 1 gallon; pulverized rosin, 2 quarts;
put in trough with cover, where sheep can have free access. When sheep become
thoroughly infested with worms death is almost sure to follow, but the above, if

_ kept before the sheep, will surely act as a preventive. — :

A more complicated arsenical recipe for worms, the source of which
is unknown, is as follows:

Take of arsenic, washing soda, and carbonate of soda, each 1 ounce;
put them into 2 quarts of hot water; boil, and stir for one-half hour,
then add 10 quarts of cold water. The dose for a lamb, after weaning,
js one-third of a gill. If the lambis not very sick give but one dose,
but if badly affected repeat in nine days. :
Fig.
Fig.

Fig

g.

Fig.
Fig.
Fig.

Fig.
Fig.

_

a

8.
9.

144

STRONGYLUS CONTORTUS, Rud.

PrLatre XVIII.

Adult female, x6: a, head; b, ovaries wound around the intestines; c, ¢,
uteri; d, a large papillw, just in front of and covering the vulva; e, anus.

. Adult male, x6.
. Head: a, two barb-like papille ; b, mouth; c, esophagus; d, intestine.
. Eggs, highly magnified: a, eggs before they have left the ovaries; b, eggs

showing nuclei; ¢, eggs after they have passed through the oviduct; d,
egg with one cell; e, with two; f, with four; g, with eight; h, with
many; i, egg as it is laid.

. Skin, showing nine of the eighteen longitudinal lines,
. Portion of female: a, the intestine; b, , the ends of the ovaries.
. Caudal end of female: a, the anus; b, the vulva; ¢, vagina; d, 4; uteri

filled with eggs; e, oviduct; f, f, ovary; g, intestine.

Spicula, enlarged.

Bursa, expanded to show cost: a, ventral; b, ventro-lateral; ¢, lateral; d,
dorso-lateral ; e, dorsal; f, spicula.

Fig. 10.G roup of adult males and females, natural size.
Fig. 11. Caudal end of male: a, bursa; 0,spicula; c¢, seminalreservoir; d, iatestine.
PLATE XVIII

 

 

 

 

 

 

Lith. Balhretore

AMoen & Co.

Geo, Marx, del.

STRONGYLUS CONTORTUS,

(Tne Twisted Stomach Worm.)
INTESTINAL ROUND WORMS.

Sheep in this country harbor at least six species of round worms,
parasitic in the small and large intestines, which their ancestors brought
with them from Hurope. They are: Strongulus filicollis, Rud.; Strongy-

_lus ventricosus, Rud., both found in the duodenum; Dochmius cernuus,
Creplin, found in the small intestine; Ascaris lumbricoides, Linv., also
found in the small intestine; Trichocephalus afinis, Rud., found in the
cecum; Sclerostoma hypostomum, Diesing, found in the large intestine.
A seventh species, Gisophagostoma Columbianum, Curtice, is found in
the large intestine and is probably indigenous to this country. Of all
these the last species produces by far the most injury. Dochmius cer-
nuus is next in importance. The injury inflicted by the others may, at
times, and in conjunction with other parasites, be considerable; but»
disease which may be ascribed to either species alone has not yet been
reported. From personal observations it is believed that the number
of individuals in each sheep are usually too few to ever cause extensive
loss, and that their greatest harm is from the little discomforts which
they may add to those produced by the more destructive parasites.

At certain seasous of the year some of the above species are abun-
dant, while at other times but few individuals may befound. Strongy-
lus filicollis and S. ventricosus are usually found associated together, but
are so small that they can easily be overlooked, or if found may be re-
garded as the young of other species. Dochmius cernuus is about an
jnch long, and being large is readily detected. Ascaris lumbricoides is
rare, having been met with only a few times by helminthologists in any
country, and in but one lot of sheep by the author. Trichocephalus
afinis is usually found in young sheep, but is met with in comparatively
small numbers. Sclerostoma hypostomum seems to be a rare species in
the East, the single instance in which it was met with in these investi-
gations being in examining an old sheep in Colorado. (Msophagostoma
Columbianum seems to take the place of the last-named species in the
East, and is found most abundantly in spring and summer in its adult
state, although it is present throughout the year. The most favorable
time for collecting most of these species has been in late fall and win-
ter. The quantities in which the various species may be found vary
with the season and the flock examined, so much so that no accurate
statements of percentage of occurrence or of distribution can be made.

The symptoms which these worms produce are those of general debil-

23038 A P-——10 145
146

ity and indigestion. They are caused by the irritations set up in the
intestines by the worms. It is found as a rule that a weakly sheep is
attacked by more than one species of parasite at a time, and, conse-
quently, it is difficult to learn the symptoms produced by either of them
acting alone. Then, too, it should be remembered thatsymptoms are
sometimes incorrectly attributed to parasites when they really result
from diseases due to entirely different causes. Even the fattest sheep
harbor a few parasites, and some of them wany more than one would
suspect from their apparent good health.

The treatment should be directed toward keeping animals in good
health and in preventing them from acquiring parasites by providiug
them with pure water and pastures which are not overstocked. Medic-
inal treatment will rarely be attempted for any single species of these
parasites. A remedy which would prove effective for any one of them
would do for all.. Their treatment will therefore be embraced under
that for Dochmius cernuus.

STRONGYLUS FILICOLLIS, Rud.
Plate XIX.

Description.—Male, 8 to15™™; female, 16 to 24™™, Body very small; cephalic end
* thread-like and tortnous; caudal end, especially of female, thick and straight. Skin
marked by longitudinal lines standing at about equal distances apart. Head very
small, subspherical, continuous, with a swollen cylindrical neck; the length of the
inflated portion is about ouve-fourth that of the esophagus. Four head papille visi-
ble; the lateral papilla are probably present, but can not easily be made out. Mouth
terminal; apparently without chitiuous armature. (esophagus linear spatulate ;
unicellular gland ducts present. Position of ventral cleft not determined.

Male: Filiform and uniform in size throughout its length; bursa strongly bilobed ;
the membrane being well filled on the dorsum but absent on the ventrum ; can not
be spread without tearing; costz generally symmetrically arranged, ventral slightly
separated; ventro-lateral either joined to lateral or ventral; lateral scarcely sepa-
rated; dorso-lateral joined to the dorsal, dorsal notched and with the dorso-lateral
form a stem, the two pairs uniting to form the dorsal stem; the lateral costa are the
jongest. Spicula 1.5™™ long, cylindrical, very slender and dark colored; their
points are tipped with an oval inflation of the membrane and are more or less firmly
attached.

Female: Tail obtuse; vulva situated about one-third of the entire length of the
worm from the tail; body of the egg-bearing female enlarged in front of the vulva
by the swollen and crowded uterus. Uteri directed each way from the vagina, and
filled with comparatively few and large eggs in all stages of segmentation. Eggs
0.17™™ long, 0.08™™ wide, ovoid ; laid in the morula or gastrula stages. Embryo vot
observed. 5 :

This species occurs with Strongylus ventricosus in the upper end of
the small intestine of sheep and lambs. Itis often mistaken for the
young of other species, and has been identified as a variety of Strongylus
contortus. It is needless to observe that it is specifically different from
any other nematode found in sheep; a glance at the plate illustrating
the species is sufficient proof of this, It is quite abundant during fall
147

and winter. European observers seem to find it rather infrequently.
The species appears to be a comparatively harmless one. It is probably
the young of this species which Wedl found associated with Tania
expansa, and named Trichosoma papillosum. Wedl characterized it as
having a double uterus and the mouth furnished with four papille.
Neither of these characters is inconsistent with Strongylus filicollis,
while the fact that Wedl’s species, with a double uterus, was classified
in a genus which has a single uterus and spicule indicates an error.
Fig.
Fig.
Fig.
Fig.

148

STRONGYLUS FILICOLLIS, Rud.

PLATE XIX.

. Adult male, natural length indicated by line: a, head; 6b, bursa and spicula;

c, worm enlarged twice.

. Adult female, natural length indicated By line: a, head; b, vulva; ¢, anus;

d, worm enlarged twice.

. Head: a, mouth surrounded by four papilla; 0, esophagus; c, inflated skin

surrounding head and neck.

. Skin: shows nine of the eighteen longitudinal lines.

Cephalic end: a, the head; 6, the esophagus; c,¢e, the unicellular gland
ducts.

. Bursa: a, the spicula; b, their knobbed tips.

. Portion of the spicula enlarged.

. Ovary of female with inclosed eggs showing segmentation.

. Bursa spread ont: a, ventral costa ; b, ventro-lateral; c, lateral; d, dorso-

lateral; e, dorsal.
PLATE XIX

 

A.Hoen & Co. ith, Baltimore

Haines, del.

STRONGYLUS FILICOLLIS
(The Thread-Necked Worm.)
149

STRONGYLUS VENTRICOSUS, Rud.

Plate XX.

Description.—Male, 6™™; female, 13™™, Body very small and comparatively stout.
Males and young females usually spirally coiled; body of old female straight, with
cephalic end coiled. Skin transversely striate, marked by fourteen longitudinal
lines; the five larger standing at equal interspaces on the dorsal and ventral sur-
faces, the two smaller standing close together on the sides. The crossings of the
striw and longitudinal lines make pits which are quite characteristic. Head little
larger than neck, but hemispherical and continuous with the cylindrical inflation of
the neck. No head or neck papill visible. Mouth terminal, very small and round.
The end of the head is furnished with a hemispherical cap-shaped chitinows piece.
Other oral armature apparently absent. Inflated portion of head about one-fifth the
length of esophagus. Unicellular glands not apparent. Male about one-half the
jength of female; bursa conical and bilobed, the ventral membrane being narrow,
the dorsal wide; ventral costa not separate, smaller than the ventro-lateral, which
is stout; lateral widely separate and apparently formed of three nearly equal costae ;
dorso-lateral slender; dorsal notchod at the end and giving off laterally a very short
side branch. Spicula 0.36™™ long, short and stout, and margined by a fringe-bearing
sinuous membrane. They are tipped by a soft pad-like expansion of the membrane.
Female characterized by a swelling at the vulva, which gives the species its name.
This character is more pronounced in older specimens. Vulva from two-ninths to
one-third of the entire length of the female from the tail. Uteri directed anteriorly
and posteriorly from the vagina. Ova 0.13™™ long, 0.07™™ wide, comparatively
large, and found in all stages of segmentation. Embryo not observed.

This species is found in association with Strongylus filicollis in the
upper part of the sinall intestine of sheep. It can be separated by its
smaller size, its spiral twist, and the markings of the skin. It is best
found in fall and winter. The specics was originally described from
specimens taken from cattle, and so far as known has never before
been noticed as being found in sheep. The female in its adult stage re-
sembles the small specimens of S. filicollis. It is apparently the cause
of little or no disturbance, although from the appearance of its mouth
parts it might seem to be more injurious than 8. jilicollis.
150

STRONGYLUS VENTRICOSUS, Rud.

PLaTE XX. %

. Male, natural size indicated by line and smull figure of worm: a, head ; b,

bursa and spicula.

. Female, natural size indicated by line and small figure of worm: a, head;

b, genital orifice.

. Head: a, mouth; bb, chitinous cap surrounding it; ¢, esophagus.
. Portion of skin showing eight of the fourteen lines: a a, the two lateral

lines: b b, the dorsal and ventral lines. The dots indicate depressions
where the Jongitudinal and the latitudival lines cross.

. Cephalic end: a, head; b, esophagus.
. Spiculum: a, its chitinous portion; b, the protractor muscle; ¢, the fringe

edging the membranous portion; d, the distal end covered by membrane,

. Female, natural size indicated by line: This female is more characteristic of

the species than that of Fig. 2, but is not quite mature.

. Bursa witb spicala.
. Bursa spread out: a, ventral cost; b, ventro-lateral; c, lateral, of which

there seems to be an accessory branch; d, dorsal-lateral; e¢, dorsal, which
also has an accessory branch.
PLATE XX

 

. Baltimore.

A.Hoen & Co, Lith

Haines, del.

STRONGYLUS VENTRICOSUS

(The Ventricose Worm.)
THE LARGE ROUND WORM.
ASCARIS LUMBRICOIDES, Linn.

Plate XXI.

_Description.—Male and female 150™™ each ; in the specimens figured 120 each. Body
very large and thick, obtuse at each end, of a yellowish color, skin marked by rings.
The site of the vulva is marked by a smooth wide band about one-third the entire
length from the head. There are three longitudinal bands; the two wider are nearly
lateral; the third is ventral. The head end is abruptly terminated in three well-
formed lips; the dorsal possesses two papillie near its base and the two ventral one
each. Each lip consists of a vhitinous support covered by cuticular membrane. The
tail of each is obtuse. The description after Schneider (Monographie d. Nematoden,
p. 36) is as follows:

“‘ Lips nearly equal, their form changing from semi-circular to quadrangular. Teeth
very fine. The lobes undivided. The azygos lobe has a rounded point, and reaches
with its anterior end to the front of thesaddle. Cuticularrings longitudinally ribbed,
Vulva 40 to 65™™ from the cephalicend. Vagina 11™™ long. Tail of the male flat ow
the ventral side. Only behind the anusis the skin broadened into a bursa; sixty-nine
to seventy-five papillae on each side; the first seven pairs of these papille stand behind
the anus; the second pair stand nearer tne ventral line than the first and third; the
fourth and fifth pairs and the sixth and seventh pairs are united into double papilla.
(See Fig. 7.) The succeeding stand first in a single row, then in pairs forming a
double row; and on the whole they are very irregular. An unpaired papille stands
in front of the anus. Spicula two, each a single tube, with its point terminating
bluntly and irregularly in front.

“This parasite occurs in the small intestine in man and swine, and sometimes
forces its way into the gall ducts, stomach, esophagus, nose, and lungs.”

In one flock of sheep only has the author found this parasite. In this
flock it occurred in six animals, a majority of those examined. That it
is not a common parasite is attested by the writings of various Euro-
pean helminthologists. A few of the latter have described a special
species (Ascaris ovis), from the sheep, but as it is infrequently found it
seems to be an inconstant parasite or an adventitious one, 4. ¢., it is
probably a constant parasite of some other domesticated animal, and
occasionally only becomes parasitic on sheep. Besides, the specimens
figured always seem to have been immature, and do not differ from
Ascaris umbricoides of the same size and age.

In the single flock in which this worm was observed all the specimens
found were immature. The vegetative organs of these specimens differ
in no essential point from those of Ascaris lumbricoides as figured by
various authorities. In addition, a close comparison of these specimens

‘ 151
152

with equally immature Ascaris taken from pigs gave no determinable
differences. These remarks presuppose that A. lumbricoides of man
and A. swilla of swine are identical species. The description seems to
be incomplete, but as the species is neither peculiar to nor commonly
found in sheep no attempt is made here to enlarge it. The species can
easily be determined by a comparison with the figures.

Sheep probably acquire this parasite while pasturing after swine.
As few are infected, little harm is accomplished by the Ascaris. It is
more abundant in summer and fall than at other seasons.
Fig. 1

zy
I! 98
~©

Fig. 4
Fig. 5
Fig. 6

154

ASCARIS LUMBRICOIDES, Linn.

PLaTE XXI.

. Adult male, natural size.
. Adult female, natural size.
3. Top view of head onlarged; a, dorsal lip with two papillz; b, b, ventral

lips with one papilla each.

4, Head, veutral view.
. Head, dorsal view.
. The lips greatly enlarged and flattened: a,a, papilla; b,b, the serrated

edge of chitinous support.

. Tail of male, ventral view: a, anus; 1, 2, 3,4 and 5, 6 and 7, the post-

anal papille; 8, the unpaired pre-anal; 9, 9,9, other papilla.

. The two spatulate spicula: 8a, one of these enlarged.
. Portion of female: a, the genital opening; 6, the ventral line; ¢, one of the

two lateral lines.

. Tail of female, lateral view.
. The same, ventral view.
PLATE XXI

 

A.Hoew & Co, Lith, Baltimore

Haines, det.

ASCARIS LUMBRICOIDES,
(The Common Round Worm.)
155

DOCHMIUS CERNUUS, Creplin.
Plate XXII.

Description.—Female, 20 to 26™™ ; male, 13 to17™™, Body very dark colored when
fresh ; whitened when preserved; attenuate towards the ends. Head curved, the
mouth being directed dorsally. Mouth round, smaller than the oral surface, and
opens into an ovoid dark-colored capsule. About the opening stand four teeth, two
on each side, their base being sunk into the capsule and their free edges projecting
into the cavity. The ventral are the larger, thicker, and more opaqne; their edges
form an unbroken sinuous line. At the caudal opening of the capsule are one pair of
ventral and a single dorsal tooth; the latter is conical, very large, and risss to near
the mouth. In the pharyngeal opening are six very small club-shaped, spinous,
chitinous appendages of the cesophageal supports or rods; they seem to be jointed.
There are six papille—dorsal, lateral, and ventral pairs. The lateral may give off
a branch on the dorsal side. There are two lateral neck papilla, nearly opposite the
middle of the esophagus; the ventral cleft is situated a little anterior to a line con- —
necting the latter. Unicellular neck glands quite plain.

Male: Bursa funnel-shaped ; will not spread without tearing ; coste unsymmetrical
as to form; ventral pair not separated ; lateral, widely separated; dorsal notched ;
dorso-lateral unequal in length and differently attached to the dorsal stem. Spicula
0.6™™ long, aculeate, fenestrated, and provided with a narrow membranous margin.

Female: Vulva about three-fifths of the entire length of the body from the end of
the tail. Vagina opening at right angles to the side of the body. Uteri, lying one
anterior, the other posterior; each forms an §-like loop; the anterior ovary is di-
rected towards the tail; aud, with the posterior, forms an intricate sinuous net-work
surrounding the intestine. Eggs elliptical; laid in the morula stage; length, 0.06™™;
width, 0.03™™.

Occurrence —This species inhabits the small intestine of sheep, and
attaches itself to the intestinal walls by its stout oral armature—the
so-called teeth. It lives upon the blood of its victims.

The life history of this species of Dochmius has not been determined,
but there is no reason for supposing it different from that of D. trigo-
nocephalus, the allied species found in dogs. This life history has been
determined by Leuckart (Die Menschlichen Parasiten, Band IL, pp. 132-
134), and is essentially this: The eggs pass from the dog to the ground,
where, in wet places, they undergo a development of the vegetative
organs. If at this stage the young are swallowed by another dog they
develop into adults. The development outside the dog may consume
from three to six days. The worm may then continue living without
further development for an indefinite time, depending on the conditions
by which it is surrounded and the favorable opportunities for being
eaten by the dog. Its development in the dog occupies about two
weeks. The time consumed may be supposed to be that occupied by
the development of Dochmius cernuus with approximate certainty.
Leuckart states that though he saw some of the embryos enter snails
while in their free living state, that this condition was an unnecessary
one, and that the worms underwent no development while in the snails.
It may be that if these parasites can enter the snails, their opportuni.
156

ties for safely passing the indefinite time prior to finding their way into
their final host are increased.

In my own experiments in keeping a number of lambs in a circum-
scribed space for five or six months after purchase, and in confining two
others raised there with them, allowing them no water save such as
was pumped for them, Dochmius cernuus were found of various sizes in
the lambs of each set. The two lambs raised on the place must neces-
sarily have acquired them there. These parasites either developed to
a certain extent in the iron watering trough or in little pools which
could have collected and remained in the yard for a day or two after a
rain, or the lambs were infected from the ary hill-side of the inclosure.

The disease can only be diagnosed by the flock-master from a post-

mortem examination. It has been recommended to diagnose these para-
sitic diseases from the eggs of the worm found in examining the feces
by the aid of a compound microscope. Such a plan is very tedious in
its execution, and impractical save to one already skilled in the work.

The disease caused by Dochmius cernuus receives little attention in
veterinary works. This is due, in all likelihood, to the fact that not
more than two or three hundred of the parasites ever seem to be pres-
ent in one sheep, and generally there are less than one hundred; then,
too, if other parasites are found present the illness would probably be
ascribed to them. If, however, we may be allowed to infer the effects
which would be caused in sheep from the effects which Dochmius
duodenalis, a related species, produces in man,* in whom it has caused
epidemics characterized by progressive anemia, and if we may accu-
mulate corroborative evidence from the disease which Dochmius trigo-
nocephalus, a third species, produces in dogs, we may fairly infer that
the species causes more disease than has been suspected. Nor is its
comparative paucity in individuals any contra-evidence, for in human
patients affected with this disease the species is represented by usu-
ally less than a hundred specimens, although as high as two or three |
hundred have been found in one patient. In dogs the author has
found about the same number. .

The intestinal lesions are obscure to the unaided eye, except at those
points where the parasites have been attached. Here, if the worm has
recently loosened its hold, there is a slight blood extravasation. The
parasites maintain their hold by the chitinous cup with its projecting
oral teeth, and in some way cause a hemorrhage, upon which they feed.
The six pharyngeal spinose appendages may aid in wounding the deli-
cate epithelial cells.

It seems impossible that a dozen or twenty, or even fifty, specimens
of Dochmius could, by creating such little injuries in withdrawing blood

 

*Literature: Wilhelm Schulthess, Zeitschrift f. wiss. Zoologie, XX XVII, 1882, pp. 163-
217. J. Ernst, Deutsche med. Wochenschrift, 1888, p. 291. A. Friinkel, ibidem, 1885, p.
443. O. Leichtenstern, ibidem, 1885, pp. 484, 486, 501, 523; 1886, pp. 173, 176, 194, 216;
1887, 565 and five following numbers; 1888, p. 848,
157

from its host, cause the severe disease and progressive anemia ascribed
to it in man, but such has been determined to be the fact from clinical
and post-mortem observations. It may be that there is a reflex, sympa-
thetic action stimulated by them of which we can take no account.
The further changes observed in patients affected with Dochmius are
much the same as in those affected with other parasites, except that
anemia with its attendant effects seems to be the most prominent.

The disease is one which begins in early lambhood and progressively
continues, the severity depending on the number of parasites entering

- the intestinal canal. The adult probably lasts through the winter and
continually lays eggs which pass to the ground. The character of the
season, of pasturage, and of the water, in being either favorable or
unfavorable to the preservation of the young worms while on the ground,
will therefore determine the amount of infection and sickness ee
the following season.

The preventive treatment for the intestinal worms is the same as that
advised for the lung worms—good care, pure water, plenty of grass,
sufficient grain feeding, salt, and separation of sick from the well. For
the reason that the disease has not received the attention its impor- .
tance demands the medicinal treatment has not been worked out with
the thoroughness that some of the other parasitic diseases have re-
ceived.

Medical treatment.—In man the most effective remedy is extract of
male fern, combined with powdered male fern, the remedy to be pre-
ceded five or six hours by a dose of castor oil. This combination is also
a good one to administer to dogs in the following proportions: Extract
male fern, 40 grains; powdered root of male fern, 75 grains. This mass
must be made into ten pills with yellow wax, and all given at once.
The dose of powder of male-rern root for sheep is from 14 to 3 ounces,
and of the extract from 2 to 4drams. As boluses are not only incon-
venient to give to sheep, and do not pass directly into the fourth
stomach, the administration should be by drenching. I should advise
that the extract be mixed with from 2 to 4 ounces of castor oil. Other
remedies advised for the round worms are wormseed, wormwood, and
santonine. The latter is an alkaloid obtained from a species of Ar-
temisia. As the prairie lambs love to eat sage, of which there are a
number of species belonging to the genus artemisia, it is likely that
these plants. may prove beneficial to them through medicinal qualities.
In my examinations of Western prairie sheep I do not now recollect hav-
ing met with as many round worus as are found in Eastern sheep. ‘The
dose of santonine for sheep is from 1 to 3 grains, given in from 2 to 4
ounces castor oil. The preparations of tansy, Tanacetum vulgare, have
long been used as vermicides. The dose*of the oil is from 1 to 2 drams,
given diluted by adding from 4 to 8 ounces of another oil. The receipt
for Spinola’s worm cake sufficient for one hundred sheep is: Take of
158

tansy root, calamus root, and tar, of each 24 pounds, of common salt
1} pounds, make into cakes with meal and water, and dry. The dose
of areca-nut powder, which is an effective remedy for round worms as
well as tape-worms, is from 1 to 3 drams for lambs.

The oil of turpentine has proven of itself a valuable anthelmintic, but
should be used with care. For intestinal round worms in sheep from 1
to4 fluid drams may be given, accordiag toage. Theturpentine should
be mixed with from 2 to 4 ounces of castor oil. Sweet or linseed oil
may be substituted, but their cathartic effects are untrustworthy. More
than one dose should not be given until two or three days have elapsed,
when, if it is deemed advisable to give a second dose, no untoward re-
sults having been noticed from the first, the dose, slightly increased, may
be repeated. Do not give more than the maximum dose. Tellor (Dis-
eases of Live Stock) gives the following recipe: Linseed oil 2 ounces,
oil of turpentine one-half ounce, for a drench. The French veterinari-
ans advise, among other remedies, the use of empyreumatic oil, petro-
leum, and chimney soot. Empyreumatic oil is animal oil, a by-product
of distillation of animal matter for ammonia. Dippel’s ethereal extract
is arefined product, and the oil of Chabert consists of animal oil 1 part,
turpentine 3 parts. The medicine should be administered as a liquid.
The dose of animal oil, or oil of Chabert, is from 1 to 2 drams, to be
given in 4 ounces of the chosen vehicle. The oils and alcohol dissolve
animal oil, but if the vehicle is a watery mixture it must be well
shaken. Bitter vermifuges made up into tea are excellent, as is also a
decoction of chimney soot thickened by dextrine or the yellow of eggs. -
From the certain effect that petroleum has on insects externally we may
infer that it should prove a valuable anthelmintic internally, if it may be
given in sufficiently large doses. It has been used in man for tenia
and round worms. The dose is 30 minims. The dose for sheep may be
as large; how much larger future experiments will determine. Until
the toxic dose is learned it should be given with caution. Itis proba-
ble that. 2 dram doses may be used. Give with from 2 to 4 ounces of
sweet, linseed, or castor oil.

Besides these there are many other remedies proposed, as savin,
sabadilla, spigelia or pink root, aloes, tartar emetic, asafetida, azeda-
rach, kousso, kamala, and pumpkin seed. The greater part are of
doubtful efficacy; others are dear, and can be replaced by remedies
equally as good and cheaper. Many of the bitter herbs may be pow-
dered and given with grain, but the sheep will not get enough to have
the besteffects. Often the worst-affected lamb will not eat any, or very
little, on account of loss of appetite. This method of administration is,
besides, wasteful. The uncertainty of sheep receiving a full dose is the
chief argument against such g~ method. The effect of some of these
plants on sheep is also modified by the fact that sheep are plant eaters
and become more or less accustomed to the various medicinal principles
found in them,
Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7.

160

DOCHMIUS CERNUUS, Creplin.

Plate XXII.

. Adult male, x 9: la, natural size.
. Adult female, X 9: 2a, natural size ; b, vulva.
. Cephalic end of male, ventral view: a, head; b, b, esophagus; ¢, c, neck

papille; d, opposite ventral cleft out of which the unicellular gland
ducts e,e, empty by a common tube, f; g, unicellular glands; h,h, two
ends of the seminal tubes; i, i,i, seminal tube; k, k, intestine.

. Head, dorsal view: a, mouth ; b, b, the chitinous oral teeth on the left side;

c,¢,¢, three papille on right side; d, dorsal teeth; e,e,neck glands; f,
esophagus.

. Head, right side. Letters as in Fig. 4: g, ventral teeth; hy chitinous

capsule.

. Pharynx and lower part of capsule of head, ventral view: a,the cut edge

of capsule; b, the dorsal tooth; c,c, ventral teeth; d, pharynx, in which
are six club-shaped bodies, which seem to be appendages of the chiti-
nous rods of the wsophagus; e, esophagus; f, enlarged club-shaped
body, which is chitinous and covered with rough points. This apparatus
seems to be for mastication.

Middle portion of female, x 30: a, vulva; b, vagina; c, c, portions of cephalic
uterus; d, d, caudal uterus with eggs; e, oviduct; f, f, cephalic ovary ; g, 9,
caudal ovary; h,h, intestine.

Fig. 8. Eggs: a,a,from ovary; b, in oviduct; the rest from the uterus in varioug

Fig. 9.

Fig. 10
- Fig. 11

stages of cell division; ¢, as they are expelled.
Bursa: a, ventral coste; b, ventro-lateral; c, lateral; d, latero-dorsal ; e,
dorsal. The two sides are unsymmetrical. :
. Spicula.
. Portion of spiculum showing fenestrations and openings into the tube: a,
tube; b, wing.
PLATE XXII

N

 

 

 

 

 

& Co. Lith. Boltin:

-Hoen

DOCHMIUS CERNUUS,
(The Bent-head Round Worm.)

Haines, del.
161

SCLEROSTOMA HYPOSTOMUM, Dujardin.
: Plate XXIII.

Description.—Male, 16™™; female, 24™™, Body white, cylindrical, andstont. Head,
globular, a little ventrally curved and truncate at the mouth; head papillw six;
neck papillw not observed; ventral cleft about opposite the end of the second fifth
of the esophagus, counting from the head. Unicellular glands and lateral lines very
couspicuous. Mouth-opening round, obliquely inclined; surrounded by a single
circle of very minute saw-like teeth. The globular chitinous capsule is marked by
numerous longitudinal elevations, which are stronger at its bottom. The posterior
opening is circular, unarmed, but roughened, Around the mouth is a circular canal
which empties into a dorsal canal. There is apparently no pharyngeal apparatus as
in Dochmins, CGsophagus slightly swollen caudally. Two lateral ducts opening near
the mouth ‘and situated on either side of the head are apparent; they seem to end
caudally iu the lateral canals. Male about two-thirds the length of the female.
Bursa shallow, set on obliquely, campanulate. Ventral costw either separate or
slightly so; lateral slightly separate if at all; dorsal pair irregular and widely sep-
arate; the dorso-lateral and dorsal forms a single stem with three lateral branches. -
Spicula 1.5™™ long, linear aculeate, cross-striated, and bordered by narrow margins
which roll in towards each other. Two anal papillw. Female stout and thick, and
usually with a brown crust near the vulva. Vulva very near the tail. Tail full to
near the end, but ending in an acute mucronate point. Uteri directed toward the .
head; one, the caudal, makes a loop at the tail. The ovaries show loops near the
tail. Eggs elliptical, 0.1™ long, 0.06™™ broad, laid in the gastrula stage. Embryo
not observed. .

Occurrence.—Sclerostoma hypostomum is found in the large intestine
of ruminants. It is present associated with Gsophagostoma Colum-
bianum in sheep in this country, but not abundantly. It is closely re-
lated to Sclerostoma equinum of horses, a species said to make tumors
in the intestines. As S. hypostomum is rare, it has not yet been deter-
miued whether it causes intestinal tumors in sheep. Since S. tetracan-
thum, whose embryos make tumors in the cwcum of the horse, is more
nearly related generically to Gfsophagostoma than to Sclerostoma, I am —
inclined to believe, as I have proven in regard to @sophagostoma Colum-
bianum in sheep, that the species belonging tu the genus Gtsophagostoma
are intestinal—tumor-making parasites rather than those of Scleros-

toma..

Life history.—M. Baillet (Nouveau Dict. de Med. T. VII, art. Hel-
minthes, 1886) is authority for the following:

The sclerostome of ruminants is reproduced in the same way as that of solipeds,

Its eggs, of which the vitellus is segmented in tho uterus of the female, are laid in
the large intestine and carried without by the fecal material, They are hatched after

23038 -A P—-11
: 162

a few days, and the embryos are very similar in their general form to those of Scleros-
toma telracunthum. They are cylindroid, sabobtuse at the anterior extremity, and
provided with a narrow tail much shorter than those of the young sclerostomes of the
horse, They move, besides, in the same manner as the latter. They can live a long
time in the fecal material of ruminants when they are not dried, and in this condition
they grow. Some young Sclerostomes which, after hatching, were 0.35™™ long to
0.50™™ have been found in the droppingsof sheep. After having been kept damp two
and a half months these were from 0.66 to 0.78™™ long. Their skin, which is folded
on the surface of the body, appears to indicate that, like the Sclerostomes of the horse,
they are prepared to undergo a molt. The young Sclerostoma hypostomum can live a
long time in water after having reached a definite size in the fecal material of rumi-
nants. /

We have not yet observed cysts within the mucous membrane of the large intes-
tine of sheep.* But as the Sclerostoma hypostomum are in far less numbers of
ruminants than S. equinum or S. tetracanthum in the horse, we can not yet draw
any conclusion from the negative result of our researches. We will not say then at-
present whether the Sclerostomes of ruminants pass the second phase of their exist-
ence in cysts, or whether they are developed in the intestinal canal itself in the
midst of alimentary material which is found contained there. The egys of the Sele-
rostomes of ruminants taken directly from the uterus of females and preserved in
water at a temperature of from 12 to 20° C. (about 55 to 70° Fah.) hatch at the end
of four or tive days after having undergone all the series of successive modifications
which are alike observed in the eggs of Sclerostomes of solipeds.

The only possibility of error in Baillet’s experiments is the indentifi-
cation of the species with which he was dealing, for he writes:

It (Selerostoma hypostomum) is above all very frequent in sheep. There are often

‘ found individuals, probably younger, whose mouth, entirely terminal, is less widely
open, and provided with a single rank of teeth still less numerous. These worms
also lack a pharyngeal capsule, and often carry a membranous swellipg on the sides
of the head.

The above describes Gsophagostoma venulosum quite well, and when
the learned helminthologist did not experiment with eggs taken directly
from the adult worm he may have had to do with the eggs of either.
Tiis would account for the similarities found between some of the
young embryos experimented with and those of Sclerostoma tetracan-
thum. .(The author is of the opinion that the last named species should
be classed with the Hsophagostoma instead of the Sclerostoma.)

The life history of this species is, that the eggs are scattered by the
sheep, that they then develop somewhat, and without the need of any
secondary host are capable of further development in sheep when taken
by them along with the food or drink, and that in the large intestine of
the latter they may or they may not make tumors during their embry-
onic stages.

The prevention and treatment is the same as for other intestinal
worms.

* This indicates that Canphagedione Botandin hunt as so been observed in France,—

Cc, C,
Fig.

Fig.
Fig.

Fig.

Fig.
Fig.

Fig.

Fig.

Fig.
Fig.
Fig.
' Fig.

Fig.

Fig.

1.
2.
3.

4.

5.
6.

164

SCLEROSTOMA HYPOSTOMUM.
Puatre XXIII.

Male, x8. Fig. la, natural size.

Female, x8. Fig. 2a, natural size.

Head, ventral view: a, the capsule; b, the dorsal canal; ¢, lateral ducts; d,
esophagus.

Head, lateral view: a,c, d, asin Fig. 3; e, the three head-papillw; f, the com-
mon duct of the joined unicellular gland ducts is placed near the ventral
cleft; g, the end of the wsophagus, showing three dependent lips; h, the
cut-end of the skin, The drawing shows the longitudinal muscular band,
separated into two groups by the lateral canals, i, i, and the three separa-
tions of the muscular bundles between these canals which appear on the
surface as lines; k, k, k, cut end of the intestine.

Head, dorsal view: a, b, c, and das in Fig. 3.

Mouth end of lateral half of chitinons capsule: a, a, a, the ventral, lateral,
and dorsal head papillw; b, the dorsal canal which continues around the
head in ¢, ¢; d, the mouth, around which is a circle of small thorn-like
teeth, about forty in all.

6a. Teeth enlarged.

7. Caudal end of capsule: a, the cut wall; b, the dorsal canal; ¢, the ier:
lar opening of esophagus.

8. Section of wsophagus: a, a, a, the chitinous support; b, b, b, the walls, c,
the orifice.

9. Male bursa with spicula.

9a. Portion of spicule: a, the chitinous cylinders; b, the membranous margins,

9b. Diagram of anal papillie.

10. Bursa spread ous: a, ventral costie; b, lateral; c, dorsal; d, the torn edge.

11. Caudal end of female: a, anus; b, vulva; ec, ¢, uteri; d, d, loops of the
ovaries; ¢, e, the intestine; /, a dark brown patch usually found on the
vulva; g, an egg.

12, Cross-section of female: a, intestine; b, ovaries; c, lateral ducts; d, muscu-

lar bundles (Leuckart).

Figs. 3, 4, 5, and 6 are somewhat distorted by flattening.
PLATE XXIII

& Co. Lith Baltimere

sHoen

<

 

SCLEROSTOMA HYPOSTOMUM
THE NODULAR DISEASE OF THE INTESTINES.
CESOPHAGOSTOMA COLUMBIANUM, Curtice.
Plates XXIV, XXV, XXVI, XXVII.

In the Eastern States there exists a hitherto undescribed disease,
whichis characterized by tumors present in the upper part of the large
intestine. The disease causes heavy losses, for it seriously affects the
health of the sheep, and renders the intestine valueless for making
sausage casings. Though the latter result would seem trivial at first
sight, it is by no means unimportant, for sausage-makers are compelled
to import the greater part of covering material used in their business.
‘The disturbances of health produced are very serious, for there are places
in the South where sheep can not be kept with profit, apparently on ac-
count of this parasite alone. Dr. D. E. Salmon, Chief of the Bureau of
Animal Industry, who at one time lived in the South, performed many
post-mortem examinations on diseased sheep, and found nothing but these
intestinal tumors to account for the severe symptoms of disease which
they exhibited, and has verbally stated tiat he believes this malady is
the chief obstacle to successful sheep husbandry in some portions of the
Southern States.

Investigation.—The cause of the disease remained until the winter of
1888-89 in obscurity, but owing to a favorable combination of material’
and methods of investigation it was then ascertained. Some of the
larger soft tumors, which are characteristic of this disease, were dis-
sected from the intestine, and after being slit open their greenish,
cheesy contents escaped in a watch-glass of water. By carefully teas-
ing the apparently newer portion of these masses a little worm, the
cause of the trouble, was found. Previous to that time Dr. Theobald
Smith, of this Bureau, had in the winter of 1886-87 made and examined
niicrescopic sections of these tumors. One of a series of sections (see
Plate XXV, Fig. 8) showed what was apparently the fragment of a
worm. Numerous other sections made at the same time showed no
signs of this parasite, and the investigations were temporarily aban-
doned.

Although tuberculosis is an uncommon disease in sheep, and although
the tumors found in this disease differ in many essential points in both
their history of formation and in their histological detail from those
caused by tubercle bacilli, there was a superficial resemblance, on

165
166

account of which Dr. Smith made many tests of the caseous matter for
the bacilli both by the microscopical methods and by the inoculation of
small animals. In the light of subsequent investigations it is needless
to say that these tests had only negative results. In justice to Dr.
Smith it should be stated that he undertook the experiments more for
negative evidence than from any expectation of finding bacilli.

The cause of the disease is a nematode or round worm, which, though
remarkably similar to some other worms of its group, is nevertheless a
distinct species from any hitherto described. The failure to find this
worm in our earliest investigations may be ascribed to two important
factors. The first is that of the season of observation. We had proba-
bly overlooked those tumors which were best adapted to show the worms,
but mainly on account of the season in which the examination was made.
The method of examination was probably the greatest factor in the in-
vestigation, for as soon as what may be termed macroscopic superseded
microscopic methods the discovery was easy. The method was not en-
tirely macroscopic, for simple lenses of low power were used.

The worms found in the largest tumors were never over 3 or 4™
in length, and presented only an embryonic development, the vegetative
organs alone being present. Figs. 1, 2, and 4,in Plate XX V, were
made from the largest specimens. As the adult worms of this class
may differ materially from the embryos in the character of the mouth
parts and in their appearance after the reproductive organs have de-
veloped, the difficulty was encountered of connecting the embryonic
cystic form with an adalt form existing in sheep or elsewhere.

Determination of adult.—The most conclusive method of determining
the adult would be to directly develop an embryo into an adult, but
this proceeding was not attempted on account of its difficulties. A less
satisfactory method remained of finding some adult worm whose em-
bryo was unknown, and which not only corresponded in structure with
the embryo, but whose life history was such that it was possible for it
to be the parent of the embryo. It will not be profitable to detail
theories advanced to aid in this investigation; suffice it to say that
while studying one day a group of worms which came from the large
intestines of sheep, I found among them an undescribed species.

This species was immediately referred to the Sclerostomine (Raillet,
Flements of Zoologie, p. 330), and later to Moliw’s genus Msophagos-
toma. There may be an impropriety in accepting this name over others
proposed at the same time for species of this genus, but as the same
author proposed them, and as the genus is in general use, it is accepted
in this classification. For reasons assigned hereafter in a description
of the species I have called it a new one—Csophagostoma Columbianum.
The specific name is from the fact that the worm was first found in the
District of Columbia. :

The adult worm is found in the large intestine of sheep in considera-
ble numbers, and in the same animal may also be found the tumors.
167
The parasite is usually found below the narrowing of the large intestine,
where the latter changes from a sack-like receptacle to # large tube,
and below the mass of the tumors. The tumors may, however, extend
the entire length of the intestine. It is evident that the distribution of
the eggs of this adult oe be favorable for sheep becoming again in-,
fected by them.

The oral armature of the embryo from the tumors and the adult @so-
phagostoma Columbianum differ, that of the embryo appearing to be like a
chitinous cup comparable to that found in the young of the Sclerostoma
of sheep and the Dochmius of dogs. The young of these species, however,
differ as much from their adult form as the embryo in question does
from its supposed adult form.

The anatomical point that the writer considers of the most moment is
that the embryos of the tumors possessa lapel-like fold on the ventral side
of the worm just anterior to the ventral cleft, the opening of the unicellu-
lar gland duct, and that the adult O. Columbianum possesses a similar
fold identically situated. (See Plate XIV, Figs.1, 2, and 3, and Plate
XXYV, Figs. 2 and 3.) The absence of this feature in the embryos of
Sclerostoma and Dochmius that infest sheep at once precludes the possi-
bility that we have to deal with these species. That embryos of this
character and corresponding adults are found in the same sheep makes
the diagnosis more assured. Should we look for a host in some other
animal we should expect to find one that had all the opprtunities of
spreading the eggs that infect the sheep, but amongst our farm animals
we find no corresponding parasite, and other wild animals which might
be suspected as hosts are at the present time very rare.

CHSOPHAGOSTOMA COLUMBIANUM, n. sp.

Description.—Male, 12 to 15™™; female, 14 t0 18™™, Worm similar in appearance
to Dochmius cernuus, but having its head bent into the form of a hook. Head ter-
minal, very short, somewhat thicker than the neck, and separated from it by a con-
striction. Papille six, of which two are dorsal, two ventral, and two lateral. The
latter are more obtuse and are the openings of the lateral canals of the body. Mouth
terminal, supplied with a chitinous armature, consisting of an annular ring, which
supports two systems of twenty-four teeth each; the outer circles are very long and
curved, so that near their base they form a truncated cone and at their free extremi-
ties an inverted truncated cone. Within the outer is situated the inner and shorter
‘row of bidentate teeth, so arranged that each tooth is opposite one in the outer row.
Beneath the armature is the tri-radiate opening of the wsophagus. Neck notinflated,
but provided with a lapel or fold of skin on the ventral side just in front of the
ventral cleft; the fold continues slightly on to the dorsal side. Two lateral, narrow,
membranous wings begin at this neck fold and continue for one-fourth the length of
the worm. The two lateral opposite papillw are in these wings, at the level of the
first third of the esophagus. The pair of unicellular neck glands unite into a com-
mon duct and empty at the ventral cleft, situated beneath the nuchal fold. Male
about three-fourths the length of the female. Bursa saucer-shaped; can be spread
symmetrically without tearing. Cost« or ribs symmetrical; the ventral slightly
separated; the ventro-lateral forms with the lateral a group; the lateral also
slightly separated ; the dorso-lateral forms with its fellow and the dorsal pair a
168

vroup; the dorsal rib is composed of two, which are widely separated only towards
their free ends. Spicula two; awl-shaped, bordered by a very narrow membrane;
the chitinous cylinder is apparently fenestrated, At either side of ihe genital orifice
are two knobbed papillx. Female relatively stouter; vulva just in front of anus,
which is midway between it and the acutely pointed tail, usually covered by a hard
brown patch ; reproductive organs in two symmetrical sets anteriorly directed, ex-
cept a small portion of one, which is at first posteriorly directed to form a loop in
front of the anus. Uteri two, in the candal end of the body. These may be traced
up to the oviduct and ovaries, which continue to the cephalic end of abdomen, where
they are reflected to form a loop and thence continue to the caudal end to form still
another loop. The ovary of the caudal uterus forms still another loop nearly oppo-
site the uteri.

Eggs laid with gastrula inclosed; length, 0.09™™; width, 0.06™™, Embryos from
0.23" upwards. The largest found in tumors were 4™™ long; the smallest male
fonnd in intestine was7™™ long. The smallest embryos were without digestive ap-
paratus. The largest possessed an intestine, unicellular glands, and a well-formed
chitinous spherical cup in the head; also six cephalic papille, and at the neck two
papilla and a well-defined fold. a

Occurrence.—The adults live in the large intestine of sheep below the
cecum; the embryos live in the intestinal walls in tumors, which,
though more abundant in the cecum, may be scattered from the duode-
num tothe anus. The species is distributed in the United States east
of the Mississippi River as far north as Maryland, perhaps farther north.
On comparing the species with others of the genus it was found that it:
corresponded more nearly with Gsophagastoma venulosum, a parasite of
goats, than any other described in modern works, and that it corre-
sponded still more closely with O. acutum, Molin. (Zl sottordine degli
acrofalli. Memorie dell * * * Istituto Veneto, 1860, Vol. LX, p.
449.) The latter is apparently a distinct species, although in quoting
other authorities he has given an incorrect synonymy. 9. Columbia-
num differs markedly from O. venulosum in not having an inflated neck,
and from the Jatter and O. acutum by the possession of a lapel of skin
upon the ventral side of the neck, just in front of the opening of the uni-
cellular neck glands. Molin examined two males and three females of
O. acutum from Antilope Rupicapra; one male from Capra Hircus, var.
Mambricus, in association with forty-five Sclerostoma hypostomum; and
two males and one female from Capra Ammon. The finding of Scleros-
toma hypostomum in association with the Gisophagostoma acutum is the
favt which leads me to infer that the latter occurred in the large intes-
tine of the above mammals and not in the stomach, as he cites in his
synonymy of the species.

Life history.— sophagostoma Columbianum seems to have become a
parasite of sheep since their introduction into this country. If present
in the Old World at all it is sparingly so, and seems to have escaped
detection. So little is known about its distribution, that it is impos-
sible at present. to accurately define its limits. From its great abun-
dance in the Southeastern States one might infer that it had originated
as a sheep parasite in that region, and probably from some animal of
allied organization and habits. The writer is at present inclined to.
169

believe that the deer may have been its host at the time European
sheep were first introduced. There are few facts to sustain this hypoth-
esis. Though it may yet be too early to form a positive conclusion,
further investigation may determine the section of the world to which
this parasite originally belonged and then the former host may be in-
dicated with tolerable accuracy.

The life history of this parasite seems to be completely known to us
during its development from the immature form found in the intestinal
tumors to the adult stage; but there is a period from the moment
when the eggs escape from the intestine with the excrement. to the
time when it is found again in the intestinal tumors that must remain
in obscurity. After the embryo has returned into the alimentary canal
it makes its way through the mucous coat of the intestine and becomes
eucysted there. The writer has been unable to learn how it passes
through the mucous coat, as even on the youngest specimens no sign
of armature is found. The very young forms found in the cysts show
little differentiation beyond what they could bave attained in the egg-
shell. They are soot. surrounded by a cyst which seems to belong to
them and to have been created by them; but whether this cyst is the
remains of a molt or not can not be asserted. Later in their history
they become surrounded by the products of the inflammation they ex-
citein the surrounding tissues, and eventually break from the cyst and
live in the cheesy mass of the tumor. In thisstage of their growth the
worms exhibit the intestine and oral cup and indistinct unicellular
glands. They then molt, and show all these features in more distinct
outline. Having attained a length of from 3 to 4™", or less than one-
sixth of an inch, they break from the tumors to begin their life in- the
intestine. In the latter they continue their growth and becoming sex-
ually perfect and produce eggs which eventually go through the same
cycle.

In developing, this worm molts at least three times—once in passing
out of the stage in which it has no mouth or intestines, once during —
the development of these parts as we find them in the embryo, and
once while the worm changes from the embryonic form to the adult form.

Disease.—'The harm that these parasites do the sheep is directly
dependent on their numbers and life history. Yearlings may show
considerable infection, but it is usually in older sheep that the most
abundant infection occurs. The disease isa seasonal one, in that it can
be found in best development inthe winter. The lambs begin to be in-
feeted in the summer and fall, and from that time the tumors formed
increase in size until early in the spring of the next year, when they
gradually grow smaller but probably do not entirely disappear.

Pathology.—A study of the fresh tumors by compressing the smaller
ones between two glasses and by dissecting larger specimens gives the
following results: The small tumors, which are scarcely the size of a
pinhead, are found in the submucous tissue. They appear like asac filled
170

with fluid and having a little globe floating within. By using a higher
magnifying power the little globe is seen to be a cyst with a worm
inclosed (see Plate X XV, Fig. 6). By careful dissection the cyst may be
separated (Fig. 5), and finally the worm itself may be separated (Fig. 3).
At this stage the worm shows little differentiation of parts. In exam.
ining another and oider cyst (Plate XXV, Fig. 7) the same appearance
may be observed. There is also a little greenish cheesy substance
present. A third stage (Plate XXVI, Fig 3) shows the latter still fur-
ther increased, and in the figure referred to the arrow shows that the
encysted worm has been pressed out of this mass, leaving a cavity be-.
hind.

When the little tumors become larger than a pinhead and entirely
filled with the cheesy matter their structure does not materially change,
but is more difficult, to make ont. It is at this stage that the worm
escapes from the cyst aud begins to wander within the capsule which
its presence in the tissne has caused. On dissecting the large fresh
tumors the worm is found in the mass of cheesy material, which is now
quite abundant, filling the cavity and producing tumors as large as
the end of one’s finger. This cheesy material is usually hard, dry, and
brown at one end, and soft, yellowish-green at the other. It is in this
end that the worm is to be found. If some of the harder tumors are
examined, it may be found that there is no greenish material in them and
no worms. These hard tumors may be of all sizes and are found at all
times. From these the worm has either escaped or in the case of the
smaller tumors the worms have died. The form of these tumors is
usually spherical, but the cheesy material may appear as a long mass,
orit may apparently fill what seems to have been a worm track. The
last appearance occurs most often in the small intestines. From the
mucous side these tumors present little if any color. The older ones
may present a greenish-yellow appearance, especially if the mucous
membrane over them be thin. In well-advanced cases, when the tumors
are numerous and large, many are found in which the mucous membrane
over them is ruptured and the cheesy mass protrudes into the intestinal
cavity. In these no worms have been found, and hence the conclusion
has been reached that the worms have escaped.

In lambs the little dots indicating the presence of the young tumors
are very scattering (see Plate XXVI, Fig. 1), but in older sheep they
may be very numerous (see Plate XXVII, Fig. 1). Between the stage.
in which a few are scattered here and there over the cecum and that
in which the cecum has become a stiff tube with walls from one-fourth
to one-half inch in thickness (so thick and close have the tumors be-
come) there are all varieties. The tumors may extend from the cecum
to the anus. They may also be abundant along the small intestine.
The cheesy material which the worms produce has been found in the
lymphatics, on the omentum, and in the liver, but in these places it
never seems to be sufficiently abundant to show that the parasite lived —
long.
171

Microscopic serial sections made from alcoholic specimens show best
the changes which have taken place in the surrounding tissue. On
Plate XXVI, Fig. 2, there is figured an enlarged view of one of the
worms still encysted and surrounded by the tumor of inflammation.
From this section it is seen that the irritation setup in the adjoining con-
nective tissue causes the cells to proliferate and crowd closer and closer
together. It is also seen that there is a special cyst for the worm and
a thickened adjoining portion of the tumor which is like a surround-
ing membrane. As these two membranes, the so-called cyst and the
outer one, stain so nearly alike, it has occurred to me that they represent
successive efforts of the adjoining tissue to protect itself against the
parasite; but in view of the fact that the inner one is so easily enucle-
ated, itis for the present considered as belonging tothe worm. At the
foot of Plate XXV, Fig. 8, there is given an illustration of a small
tumor in which the worm has escaped from the cyst and in which the
surrounding matter has become cheesy, some of it even hard. Around
the entire mass the tissue is slightly thickened and forms a capsule.

From these two microscopic sections we can learn how these tumors
grow. The worm penetrates to the submucous tissue and. irritates it.
The adjoining cells rapidly increase in number and crowd upon each
other. So closely do they crowd and so numerous do they become, that
the outer layers cut off the circulation from the inner cells and they
die. Their degeneration gives rise to the cheesy mass. Now, if the
worm remained in the center of the mass the new growth would event-
ually cease, but the worm makes its way to the outside and at that
point keeps up this irritation and new growth. This is shown by and
accounts for the dried older parts of the larger tumors and the fresh
yellowish-green adjoining parts. As soon as the worm escapes the irri-
tation ceases, the tumor shrinks, and absorption of the inass begins. The
irritation produced by the worm provides it with food and favorable
surroundings for development. Often the worm dies from weakness or
other cause, and leaves behind those little hard ingomplerly: grown
tumors which have been mentioned.

Since writing the above life history two post-mortem examinations
have been performed, which lead me to modify my views regarding the
life history of certain other tumor-making parasites. On August 10,
1889, two lambs, one five months old, the other eleven weeks old, died.
The older lamb was bred at the experimental farm; the younger was
bought with its dam when but a day or two old. These lambs had no
water save what was pumped from a well. Among other parasites,
each species being found in its proper portion of the intestine, there
were numbers of individuals of Cfsophagostoma scattered through the
length of the large intestine. These individuals were of all sizes, from
the smallest stage (7™™ long) to those nearly adult. In the younger
lamb there were but few very minute tumors in the coats of the large
intestine. In the older the tumors were somewhat larger, but none were
172

much larger than a millet seed. The abundance and size of the free
parasites indicated that most if not all of them had developed in the
interior of the tube. The intestinal tamors indicated that there were
others developing in them.

From the above it seems probable that this species develops nor-
mally in the intestine, that some of the young embryos penetrate into
the walls of the intestines, and at times even to the mesenteric lym-
phatic glands and elsewhere; that those which penetrate into the intes-
tinal wall either develop very slowly or eventually die, depending on
the tissue penetrated and the favorable conditions the latter offer for
the nourishment of the parasite ; that those which develop slowly may
in time escape from the tumors and complete their development in the
intestinal canal; that this phase of its life history may be one that is
favorable for the preservation of the species by preserving a few indi-
viduals in tumors throughout the winter which escape in early spring,
become adult, and lay their eggs, which are scattered on pastures favor-
able tothe preservation of the embryos; that the majority of these
embryos, penetrating the intestinal walls, wander into such environ-
ments that they are eventually destroyed; that this act of migration is
voluntary and only of benefit to the parasite when the latter becomes
lodged in the proper place, and that the same power which enables it |
to arrive at these places also enables it to penetrate farther than is of
use to it; that the slow development of the worm in the tumors as
compared with the development in the intestine shows it to be a re-
tarded development, which may be hastened as soon as the parasite
again reaches the proper surroundings.

In short, the fact of the intestinal life of these parasites is demon-
strated, as well as the fact that some may wander into the intestinal
walls and undergo a retarded development before re-entering the in-
testine.

The diagnosis of this parasitic disease can only be made from a post-
mortem examination. In the living sheep there may be signs of general
debility—bloodless lips and eyes, thin sides and flanks, dry wool, ete.
It may be that nothing else will be noticed, but that the flock is not in
quite good condition ; or in severe cases the diarrhea and emaciation
may be excessive. Dr. Salmon believes the disease may bring death to
its victims in the severest cases. My own observations have been con-
tined to the abattoirs, where salable animals only are brought. As the
adult worms are comparatively few as compared with the tumors, it is
probable that the adults of this species cause but little trouble; but the
embryos, on the contrary, cause a greatdeal. The disease is an insidi-
ous one, for not only is the rate of infection gradual, increasing slowly
in amount from week to week, but the rate of development of the
tumors is very slow, apparently requiring months. It is only when the
disease is well advanced that its cumulative effects can be noticed.

The disturbance of digestion caused by this parasite is mainly due to
173

the derangements of the functions of the cecum. This derangement is
not serious until the resulting tamors become exceedingly numerous,
well advanced in growth, and press upon the more essential mucous
membrane, disturbing its functions.

The most seriously affected sheep found in the abattoirs are notice-
ably poorer, and one would be tempted to believe, were he to judge from
the “knotty” viscera, as the butchers call them, that such animals
should have died from the disease long before. These sheep usually
have diarrhea, a disease which weakens the affected animals. Flock-
masters who mistrust that their sheep are not doing well, and who
know of no cause for it, should sacrifice one or two of the poorest to.
make a diagnosis. The meat of such sheep, though not quite as fat as
other mutton, is suitable for food, and could not be distinguished in the
market from other mutton.

Prevention.—For the tumors caused by Gsophagostoma Columbianum
there is no remedy except the removal and extermination of the adult
worms. These adults are usually buried deeply in the mucous secre-
tions and attached to the membrave of the large intestine. They may
be found in considerable numbers in older sheep. The medicinal rem-
edy must therefore be one which will remove them from these places.
It is probable that such a one can eventually be found, but at present
none can be recommended. It is probable that some one of the surer
remedies advised for other intestinal parasites will do for these. In
case medicinal remedies are tried:each animal must be dosed. The
killing of the adults will of course lessen the number of eggs with which
the sheep become infested. As the eggs of this parasite pass to the
ground the sheep may get them either while pasturing or drinking.
The same care in changing pastures, in providing good drinking water
and a plentiful supply of salt, should be observed as for other parasites.
Judicious fall and winter marketing of infected sheep will also tend to
lessen the chances of infection. If pastures are known to be perma-
nently infected, then they should be turned over to other stock for a
year or two before being again grazed on by sheep. When it is prac-
tical on the smaller farms the sheep lots should be plowed and either
planted or left fallow. The object of change of pasture and of plowing
is nearly the same; in the one case, to wait until the parasites have
died out; in the other, to bury them beneath several iuches of soil, from
which the sheep-owner may rest assured they will not emerge.
Fig.
Fig.
Fig.

Fig.

Fig.
Fig.
Fig.

Fig.
Fig.
Fig.

Fig.
Fig.

Wwe

174+

CSOPHAGOSTOMA COLUMBIANUM, Curtice.

PLaTE XXIV.

. Adult male, x9, Fig. la, natural size.
. Adult female, x9, Fig. 2a, natural size.
. Cephalic end of adult, ventral view: a, head; b, cesophagus; ec, lateral

canals opening on head; 4, unicellular glands and ducts uniting and
emptying at e, the ventral orifice; f, a fold of the skin which forms a half
ring on the ventral side of the neck; the orifice e opens uncer it; g,g, two
pointed neck papillie; A, kh, narrow membranous wings; i, intestine.

. Caudal end of adult female lateral view, x45 (about): a, anus; b, vulva; ¢,

vagina; d, d, uteri; e, e, oviducts; f, f, f, loops of the ovaries; i, intestine.

. Head: a, mouth; J, b, papille of the two lateral ducts; c, c, two of the four

acute, pointed papille opening on the head; d, d, cross-section of cavity of
the head ; ¢, e, cross-section of a circular canal, which runs around the base
of the head; f, chitinous armature of the head ; g, esophagus; k, its three
chitinous supports.

. Chitinous armature, top view: a, chitinous ring; b, outer teeth; ¢, inner

teeth; d, triradiate pharyngeal orifice; e, ¢, e, the ends of the esophageal
rods. Four of the outer teeth have been removed to better show the inner
row. Aside view of this apparatus is presented in Tig. 5.

. Top view of teeth.
. Side view of teeth and basal support. ;
. The bursa spread out: a, ventral rib; b, ventro lateral; ¢, lateral; d, dorso-

lateral; e, dorsal; /, the cloacal orifice with two papillz behind.

. Spicula of male, composed of a chitinous tube surrounded by a membrane

with a narrow wing.

. Portion of spiculum.

. Eggs: a, a, as they appear when deposited; b, eggs in uterus.

. Bursa of male, side view: a, a, a, ribs; b, spicula; ¢, c, anal papillae.

. Head, top view: a, mouth; 8, b, lateral papille; c, one of the four acute

papille.
PLATE XXIV

 

 

 

 

 

 

Lap

——

 

 

 

 

 

 

A.Hoen & Cu, Lith. Holnimere

GESOPHAGOSTOMA COLUMBIANUM
(The Tumor-Making Round Worm of Sheep.)

Haines, del.
Fig.
Fig.

Fig.

Fig.

176

GSOPHAGOSTOMA COLUMBIANUM, Curtice.

PLATE XXYV.

9
. Worm in third stage, X60: a, head, with chitinous armature; b, wsopbiagus ;

c, intestine; d, unicellular glauds ; e, anus; f, line denoting vatural length.

. Cephalic end, lateral view, X150: a, chitinous cup; b, one of the six cephalic

papillw, (these are slightly distorted) ; ¢, side view of the neck-fold, under
which the gland-ducts d, d, open on the vein line; ¢, esophagus; /f,
intestine.

. Worm in first stage when 0.23", long. No internal organs were seen in

this specimen. Si

. Cephalic end, ventral view: a, head; b, neck-fold, near, which are the neck

papille g, g; c, esophagus; d, d, unicellular glands, which open under the
fold b; ¢, intestine; /f, f, glands.

. Wortn inclosed in its cyst.
. Tumor from which the cyst in Fig. 5 was taken: a, surrounding tissue dis-

sected from cecum; J, fluid-filled space; c, capsule with inclosed worm.

. Older tumor. This differs from tumor of Fig. 6, in having a movable cheesy

* mass. These tumors are distorted by compression, which makes them too
flat. Figs.6 and 7, and Fig. 3, Plate XXVI, present three stages in the dis-
ease, as seen in fresh tissues under low magnifying powers.

. Section of an advanced tumor: a, mucous membrane ; b, submucous; c, inner

muscular layer; d, outer: e, serous membrane; f, the cheesy mass of the
tumor in which is a small section of the worm. This presents a more ad-
vanced stage of the disease than Fig. 2, Plate XXVI.
PLATE XXV

 

Haines,.del ‘ A.Hoen & Co. Lith. Baltimore.
i CESOPHAGOSTOMA COLUMBIANUM ;
(Young Stages.)
Fig.

Fig.

Fig.

Fig.
Fig.

178

(SOPHAGOSTOMA COLUMBIANUM, Curtice.

PLATE XXVI.

L. A piece of mucous membrane taken from the cecum, surface view, natural
size. The patch of dots scattered uniformly over the surface represents
intestinal glands; the irregularly scattered larger dots and elevations are
the young worm tumors 1n their first stages.

2. A section through a worm tumor in its younger stage: a, a, a4, mucous mem-
brane; b, submucous connective tissue, in which are ¢ arteries and d veins ;
e, the tumor, which is made of connective tissue cells and their nuclei,
packed closely together; near its center is the worm cavity f, with a piece
of the worm, which is surrounded by a section of a special capsule; out-
side of this is a thick membrane, formed from the surrounding material.

3. Small tumor dissected from the execum: a, the outside capsule filled with
fluid, in which is b, a hard, cheesy mass; ¢, the worm in its capsule, which
has been pressed out of the cavity in the mass b. This presents a more
advanced stage of the disease than fig. 7, Plate xxv.

3a. The ruptured capsule.

30, The worm near the end of its second stage about. to ious.
PLATE XXVI

 

Haines, det. CESOPHAGOSTOMA COLUMBIANUM, Mees a etaetnee

(Small Tumors of Cecum.)
180

CSOPHAGOSTOMA COLUMBIANUY, Curtice.
PLATE XXVIII.

Fig. 1. Piece of cectim exhibiting tumors caused by the embryos of @sophagosioma
Columbianum, natural size. The various stages of growth are represented
by the different sized tumois. The smallest are better shown in Plate
XXVI, Fig. 1.

Fig. 2. Cross-section of Fig. 1, at a a; b, mucous membrane; ¢, submucous; d,
muscular and serous layers; ¢ e e, section through the cheesy masses.
PLATE XXVII

; /\
x - \
= |
| /

 

ines, del. 4 Hoen & Co. Lithocaustic Baltimore
signee, Be CESOPHAGOSTOMA COLUMBIANUM, Sa
(Large Tumors of Crecum.)
THE CACUM WORM.
TRICHOCEPHALUS AFFINIS, Rud.
Plate XXVIII.

Description.—Male and female about equal, 40 to70™™ long. Body whip-like, pos-
sessing a short, stout caudal end, 12 to 18™™ loug, and a very thin hair-like cephalic
end of twice this length. .The latter contains the esophagus and intestine; the
former the reproductive organs and intestine.

The head is very smalland thin, without noticeable papillx or chitinous armature.
It is said to sometimes have two vesicular, transparent, wing-like inflations. Skin
of the neck transversely striate, and when highly magnified shows a serration of the
sides indicating cuticular layers which overlap each other like shingles on a roof.
CGisophagus aud cephalic portion of intestine very minute ; its posterior end is large
and dark, and empties at the caudal end of the body. On one side of the head there
appears to be a canal filled with granules.

The male is to be distinguished by its tightly-curled caudal end. The testicle,
beginning near the caudal end, continues anteriorly as a sinuons tube for about two-
thirds the length of the thick portion of the worm; it then becomes plaited to the
end of the thick part, where it turns and continues posteriorly as an enlarged seminal
duct for about half the length of the thickened body, where it is constricted; the
remainder coutinues to the cloaca as @ slightly enlarged tube. The intromittent
apparatus consists of two parts, an external membranous tube bristling with spines
and an internal long, slim spiculum. It is always found exserted, and usually has
one coil in it. The tube shows at its end that the external covering coutinues
around the end into the tube to forma lining membrane, which may be retracted or
protruded. There is considerable space between these membranes at the tip, and it
assumes various forms, varying between a large sphere, as shown in the figures, and
an elongate cylindrical body. The chitinous spiculum is terminated by an acute
point. Itis from 5 to 6™™ long, with a width of 0.025™™, The tube is about three
or four times as wide. The spiny points are turned away from the end.

The female has a thick body, only slightly curved. Tail, obtuse; ovary begins at
the caudal end, continues as a plaited canal to the cephalic end of the thick part of
body, then contracting returns to the caudal end where it cularges, forms a fold, and
becomes the uterus, which empties through the sinuous vagina and the vulva at the
cephalic end, where the body begins to enlarge. Ezgs characterized by having re-
frangent polar bodies at each end. They measure 0.077™ in length, including these
bodies, or 0.056™ excluding them (Raillet). They are elliptical and dark brown.

Occurrence.—This species is found in the czcum of sheep, goats, and
cattle. When the fresh intestine is examined the worm may be found
with its slim, hair-like head firmly sewed into the mucous membranes.
The serrated structure of the skin not only facilitates the progress of the
head through the mucosa, but prevents its being pulled backward. The
thick large end, which is what one really sces at first, appears to float

free in the intestinal contents. sa
182 -

The life history of this species has been determined by Leuckart, the
distinguished helminthologist, who has added so much to this branch of
biology. He succeeded in raising young embryos from the eggs to such
astage that there was no reasonable doubt that the next stage was passed
in sheep. These he fed to a lamb, which he killed after sixteen days.
In these he found numerous immature trichocephali about 1™™ in length.
He later verified this experiment by another, with like results. (Die
menschlichen Parasiten, Band II, 494-499.)

These experiments show that the eggs of Trichocephalus affinis, which
pass from sheep to the ground, may develop there to some degree, and .
then, after being consumed with food or drink by a second sheep, con-
tinue their development to their adult stages. —

Disease and treatment.—Uniless the parasite should be present in great
abundance the species does not seem to be especially harmful. A few
may be found in nearly all lambs and young sheep, especially in the
all. The means of prevention is just the same as for other round
worms. As they are attached so stoutly to the mucous membrane it is
doubtful whether medicinal remedies would have the influence on them
that they have on those worms situated in the small intestine.
Pie.

Fig.

Fig.
Fig.
Fig.

an

184

TRICHOCEPHALUS AFFINIS, Rudolphi.

. Piate XXVIII.

. Piece of cecum with trichocephali attached, natural size: a,a, females; b, b,

males,

. Male, X7: a, capillary cephalicend; b, coiled caudal eud ; e, pau intro-

mittent organ ; d, the convoluted, and e, the straight partion of the seminal
apparatus; f, seminal reservoir; g, intestine.

. Female, X7: a, capillary cephalic cnd; b, vulva; c, vagina; d, uterus; e,

oviduct; f, convoluted ovary; g, intestine,

. Caudal end of male enlarged: a, cud of the body; b, spine-covered tube of

intromittent organ; c, its inflated end; d, spiculum.

. Cross-section of end showing how the outside sheath becomes converted into

the inside sheath of the tube: a,a, thesheath; b, the sac formed; ¢, the
hollow spiculum.

. End of sheath, much enlarged, to show the relation between sheath and

spiculum.

. The head. 7
. The vulva and vagina, with an egg in the passage.
. Eggs: a, eggs without shells; 4, egg with shell and its characteristic polar

bodies; c, intermediate between a and b.

ig. 10. Enlarged portion of worm from near the head.
PLATE XXVIII

 

 

 

Baltimore,

A. Moen & Co. Lith

TRICHOCEPHALUS AFFINIS,
(The Hair-headed Round Worm.)

Geo. Marx, del.
LUNG-WORM DISEASES.—PAPER SKIN, HOOSE, HUSK.
VERMINOUS PNEUMONIA—VERMINOUS BRONCHITIS.
Plates XXIX to XXXVI.

The lung worms which cause disease in sheep in the United States be-
long to two, perhaps three, different species. They are Strongylus ovis-
pulmonalis, Diesing, the hair lung worm; and Strongylus filaria, Rud.,
the thread lung worm. The third species, which has been reported as
infesting sheep in Europe, is the hog lung worm, Strongylus paradoxus,
an abundant species occurring in the Iungs of swine in this country,
and while ithas never been credited as having been found in our sheep
it is to be looked for. As its size and the disease it causes is similar to
that of Strongylus filaria, it will not be treated separately.

The diseases produced by these species of worins are caused by the
mechanical injuries tle worms inflict on the delicate membranes of the
lungs and the clogging up of the air passages by them and the débris
which they produce. The two forms of disease produced depends on the
different size and habits of the two species. Strongylus ovis-pulmonalis,
being very siwall, penetrates the air passages to their endings in the
brouchioles and infundibuli, and causes disease in them primarily,
while Strongylus filaria, which penetrates only into the bronchi, creates
a disturbance there which produces a solidification of the lung second-
arily. The general diagnosis of each disease is no easy matter. The
disease produced by Strongylus ovis-pulmonalis is characterized by the
spongy feeling of the lung and the presence of nodules from the size of
a mustard seed to that of a pea scattered under the surface of the dor-
sum of thelung and at its posterior free edge. These may be connected
' by agrayish, fleshy, intermediate portion of the lung into patches of con-
siderable size. The parasites can scarcely be seen by the unaided eye;
‘put if small pieces of the affected lung or a tubercle be placed in ashal-
low dish of water and teased out with needles under a tripod lens, they

ri ily seen. :
ne eae: produced by Stronglyus filaria and 8. paradoxus is char-
acterized by the posterior portion usually, or some entire section of the
affected lung appearing as a solid, usually red, mass which has lost all
of its contained air and is in a state of hepatization. A piece cut out
‘generally sinks in water, while pieces from the former disease float. If
in the latter disease the trachea is carefully slit open and the branches
: 185
186

traced down to the affected part the parasites will be found in thread-
ike bunches, completely filling the tubes.

The symptoms of lung-worm disease in sheep can not well be diag-
nosed in living animals unless the disease is far advanced, and then
only in the severer cases. Sheep affected with either disease generally
have pale, bloodless mucous membranes, harsh, dry hair, a dejected
look, more or less difficulty in breathing, and often a deep cough. The
bloodless condition of the sheep could arise trom other parasitic
troubles, but the disturbance of respiration should lead one to suspect
lung parasites.

Consumption or tuberculosis is apparently a rare disease in sheep,
and is not liable to be confused with this disease, which can always be
diagnosed by finding the parasite. Lung-worm disease differs from
acute bronchitis or pneumonia in being of slow development, and is less
severe in its symptoms. Worm diseases consume weeks in develop-
ment, while acute diseases are begun and finished in a few days.

THE HAIR LUNG WORM—VERMINOUS PNEUMONIA.

STRONGYLUS OVIS-PULMONALIS, Diesing.
Plates XXIX, XXX, XXXI, XXXII, XXXIII.-

Description.—Male, 16™™; female, 25™™ ; width, male, 0.5™™ ; female, 0.17™™, Cap-
illary integument of worm very transparent, the cavity of the body appearing asa
dark line. Head not winged; four papille ; mouth naked. Male, bursa pointed,
compressed, terminal; costie (apparently) seven; one posterior ; twice-notched ; two
pair lateral, one pair anterior; spicula symmetrical, spatulate, curved; 0.15™™ long,
divided into two nearly equal parts; the anterior consisting of a cylindrical chitinous
skeleton with a membraneous expansion, the posterior of a transversely ribbed skele-
ton, margined by a thin broad cnrved membrane, the two spicula forming a partially
closed tube. Female oviparous, with two uteri and ovaries. The formerempty into
a vagina at 0.8™™ from vniva. Vulva 0.1™™ from anus. Anus 0.08™™ from tip of
tail. Tail ends in a blunt point. Eggs in uteri 0.1™™ long, 0.04™™ wide. The eggs
segment after being laid. Embryo provided with a very sharp-pointed tail.

Life history.—The young of the hair-lung worms escape from the lungs
of infected sheep and become scattered over the pastures, yards, and
other places frequented by these animals. They are then taken with
the food or drink and in some way arrive in the lungs of the sheep.
Arriving at the extreme ends of the bronchial tubes, they break down
some of the tissues and become encysted. In the cyst they grow to
adult size and take on sexual characteristics. Escaping from the eysts
they make their way into the small air-tubes (bronchioles and bronchi),
where the sexes mate and reproduce. The eggs are then laid in sur-
rounding cavities and hatched into young worms, which make their way
into the neighboring air-chambers (infundibula). Afterwards some of
these worms may be coughed out of the lungs onto the pastures and in-
fect other sheep.

In their life history there are but one or two points about which there
can be any question. Many learned belminthologists believe that the
187

young worm must escape from the sheep in order to spend a portion of
its life on the ground or in some of the minute forms of animals before
they are capable of further development in the Sheep. Most authors
are agreed that the worm passes into the lungs by the trachea either
during feeding or rumination. The length of time which it takes the
" worm to complete its cycle of life is yet unknown. As the most pro-
nounced cases among slaughtered animalsare in the older sheep, it would
seem as though this parasite was of very slow growth, requiring years
instead of months for successive generations to produce a disease fatal
to the infested sheep. It may be, however, that man y lambs and
young sheep are so seriously affected with the parasite that they either
die or become soinferior in quality that they are never taken to the
abattoir. In this case the cycle of life would prove to be rapid.

_Disease.—The diagnosis of verminous pneumonia in living animals
is a difficult matter. Not until the disease is so far advanced that its
cure is hopeless are any well-pronounced symptoms developed. The
worst affected sheep may have a deep congh, be out of condition, and
be generally anemic, as shown by the pallor of the visible mucous mem-
brane and the dry, harsh coat. They are likely to lose flesh, but some,
if not seriously affected, fatten tolerably well.

The post mortem diagnosis is as certain and definite as the diagnosis
in life is unsatisfactory. So pronounced are the lesious caused by the
worms in the lung tissue that- any one having once seen a diseased
lung would easily recognize it again. The little tubercles, filled with
greenish material and surrounded by more or less of the thickened
lung tissue which when cut exudes a frothy liquid, are diagnostic.
The presence of the worm in these tubercles is decisive. -

The prognosis of this disease can not be definitely given. From many
examinations of affected lungs it seems to me that the disease is a pro-
gressive one, producing its worst effects as the sheep grow old. Where
the sheep are marketed young the loss from this parasite is compara-
tively small; but where the disease is wide-spread and affects whole
flocks, though but a few cents may be lost per head, the aggregate loss
to the sheep industry must be considerable. To this must be added the
loss from the disease in its more severe stages. When the disease is
once in a flock and the farm or range is infected with it there will bea
steady loss resulting until the disease is in some way exterminated.

Pathology.—The disease created is dependent upon the life history of
the parasite as to character and upon the numbers of the invading hosts
for its intensity. The changes produced in the lungs are but the aggre-
gate of all the changes which result from the different invading individ-
uals, and the history of the changes wrought by a single parasite illus-
trates the changes produced by all. The minute worm, when entering,
penetrates the air passages to their extremities. In the ultimate alveoli
it breaks down some portion of the membranous partition and becomes
surrounded by the products of the inflammation which it excites and
188

formsavery minute tubercle. When this tubercle has reached from one to
two and one-half millimeters (one twenty-fifth to one-tenth of an inch) in
size, it is composed of a distinct central part, filled with a soft, greenish,
central portion, which is surrounded by a thicker membranous capsular
portion, composed of cells of new growth, the inner part of which degen-
erates later and enters into the formation of the cheesy central mass.
Within this tubercle isthe young parasite. Inlater stages this tubercle
enlarges until it becomes 3" in diameter. In this stage the soft interior
mass will be firmer. The parasite is always found between the interior
mass and the capsule, and is surrounded by the soft, freshly-formed
greenish material, which it seems to produce by the irritation of the
adjacent capsule. When the parasite attains its adult size it evidently _
breaks from the tubercle and thereafter lives in the adjacent bronchioles.
There is quite a difference in the external appearance of the little tuber-
eles during the different stages of growth. In the earlier stages they
appear as little blood-red spots just beneath the pleural coat of the
lung; later they look like little brownish fluid-filled tumors, surrounded
by a red zone; still later a yellowish, green, cheesy material appears in
their center, and the tumors present a greenish-gray appearance. The
gray is due to the thickened capsule and a thickening of the pleura!
coat of the lung over the little tubercle. There is usually a slight ele-
vation of the surface of the lung over these nodules, but this feature is
dependent on the depth at which the nodule is situated. They may
oceur at any depth in the lang substance, but are usually near the sur-
face. When the parasite escapes from the nodule a new phase of the
disease begins. It wanders through the bronchi until it meets one of
_ the opposite sex, when they mate. Soon after the female begins to lay
eges in the bronchioles and alveoli, which she infests, and these eggs
in turn hatch into young worms. These young worms are very lively,
and help to increase the disturbance of vital functions of the lung sur-
rounding them, That part of the lung then becomes as if sodden, the
air tubes fill with eggs, worms, cast-off epithelial cells, mucus, wan-
dering cells, and air globules; the tissues of the walls of the alveoli
become thickened and encroach upon the contents, and the function of
the part is entirely suspended. The effect of the worm and its brood
at this stage is to produce a pneumonia, hence the disease has been
termed verminous pneumonia. This pneumonia is limited to the neigh-
borhood of the parasite and does not extend beyond, The patches are
from 1 to 2.6™ in width, but in those recently formed they rarely ex-
tend more than 2 or 38™™ deep. The injury seems to be mainly a me-
chanical effect, due to the irritation set up by the parasites. When
one of these patches is cut into a frothy liquid exudes, bearing quanti-
ties of eggs and embryos in all stages of development. They may be
seen with a glass magnifying six diameters.
In later stages of the disease the tubercles become little hard masses.
These have been said to be calcareous, but they are not soluble in acid,
189

and seem rather to be the contracted, hardened remains of the cheesy
mass. There are sometimes found in certain lungs raised patches of a
rather dry, emphysematous tissue, which seems to be due to the deeper
lying parasites. In other lungs the patches which once showed the
pneumonia have becomed thickened, firmer, denser, and a cut across
them shows the thickening to extend to a considerable depth.

The abundance of the nodules and patches of pneumonia is very vari-
able. There may be a dozen nodules of different sizes and twoor three
patches, or the nodules may be diffusely scattered over the whole pos-
terior surfaces of the lung, or there may be associated with them numbers
of patches due in part to the close proximity of the nodules and in part
to the extension of the disease. In other cases there may be a few of
the nodules with a series of patches ranged along the dorsum of the
lung. Each lung seems to present aslightly different phase, dependent
on the degree and the time of infection and possible reinfection.

Source of infection.—That verminous pneumonia is caused by a worm
(Strongylus ovis-pulmonalis) and that sheep become infested while feed- —
ing or drinking has already been enlarged upon. It is obvious, there-
fore, that the best way to keep the sheep well is in some way to pre-
vent them from becoming infected with the parasite while feeding.

Preventive treatment.—In giving rules for prevention the value of
knowing the complete life history is fully illustrated. The unexplained
gaps in this history are two, viz: there has been no complete demonstra-
tion of the manner and place in which the parasite spends its life be-
tween the time of its escape from the lung of one animal and its recep.
tion into that of another, nor has it been demonstrated that the worm
must escape from the luug before it may complete its development.
This latter item is an important one, for if the worms can continue
multiplying indefinitely in the lung then there is little hope of freeing
a sheep after it is once infected. On the other hand, if an infected
sheep is to be regarded as incapable of continuing the infection within
itself then the case is more hopeful. If the parasite must become para-
sitic on a second host while external to the sheep, as some claim, this
is an important factor in its life history, for its continuance, then depends
on the presence, abundance, and seasonal appearance of this second
host, and influences adverse to the life of the second host would be un-
tavorable to the parasite.

As the parasites are present in the lungs of sheep throughout the
year in all stages, this theory does not seem to hold good. The infee-
tion of lambs is proof enough that the parasites are continually passing
from one sheep to another, and whatever be the mode of living there
are certain precautions which may be taken to keep the sheep less in-
fected if not to entirely exclude the worms. The older sheep, which
seem to be more infected and which are the source of infection for young
ones, should.be marketed. Lambs should be weaned as early as they
safely can be, separated from the older sheep, pastured in fields where
190

there have been no sheep since the previous winter at least, and never
allowed to pasture, water, or yard after infected animals.

Sheep should be supplied with water from running streams or troughs,
and should not be allowed to contaminate the waterin any way. Filthy
drinking water is one of the must prolific sources of the parasite.

There are two kinds of seasons which especially favor the production
of parasitic diseases. The one is a very wet, warm season, during which
the parasites seem to be able to live on the damp ground. The other
is a very dry season, when the pools of water become diminished and
stagnant, and whatever parasitic eggs or embryos there are in them are

gathered into so small a volume of liquid that sheep drinking of the
water become more readily infected. Wet, damp pastures, and pastures
with puddles in them are alike favorable to the worm diseases. Sheep
should be excluded from such places as much as possible.

A constant watch of the condition of the lungs in dead and slaugh-
tered sheep will enable the flockmaster to judge of the progress that
his care in preventing the disease has made.

Medicinal treatment—There is no medicinal treatment that can be
profitably followed. Salting, grain-feeding, and healthful surroundings
are required not only to keep up the health of the animal for the pro-
duction of wool but to fit it fur the market, which is the best place for
seriously affected sheep.
Fig. 1.

Fig.

Fig. 3.
Fig. 4.
Fig. 5.
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10.
Fig. 11.

192

STRONGYLUS OVIS-PULMONALIS, Diesing.
PiaTE XXIX.

Cephalic end: a, wsophagus; b, intestine.

2. Head with papille.

Caudal end of female: a, anus; b, vulva; c, vagina;" d, d, uteri; e, ¢, ovi-
ducts; f, f, ova; g, g, intestine.

Middle of female with tail of male coiled around her.

Spicuium: a, cylindrical part of the skeleton; 6, spatulate ribbed part; ¢,
wing of tube: d, membranous tip.

. Spicula as they fit together.

. Adult male and female, x6.

. Caudal end of male: a, spicula.
. Male bursa with appressed costz.

Male bursa with separated costie and spicula in situ,
Caudal end of female, lettered as in Fig. 3,
PLATE XXIX

 

A.Hoen & Co. Lith, Baltimore.

STRONGYLUS OVIS-PULMONALIS

‘The Hair Lung Worm.)
194

STRONGYLUS OVIS-PULMONALIS, Diesing.
PLaTe XXX.

Portion of left lung slightly affected by the strongyli. The purplish spots are those
more recently invaded. The small gray spots are older. The large gray spots are
caused by the worms and their young, which have produced an appearance of local
pneumonia.
PLATE XXX

 

Atloen 2 Co. Lithuceustic Baltimore

Haines, del.

SURFACE OF LUNG RECENTLY INVADED BY STRONGYLUS OVIS-PULMONALIS,
196

STRONGYLUS OVIS-PULMONALIS, Diesing.
PLATE XXXI.

Left lung diseased by Strongylus ovis-pxlmonalis, the hair lung-worm. Natural
size. Each dot is caused by the irritation set up by a young worm, and its size cor-
responds to the age of the worm. The larger patches consist at first of separate
dots; as these enlarge they run together and finally become so fused that their
identity is lost. The patches show the stage at which the worms become adult and
produce their young, which wander into the adjacent air cavities.
     
   
 
  

PLATE XXXI

 

Haines, del.

orm ma om TITNA NewAceN BY STRONGYLUS OVIS-PULMONALIS.
198

STRONGYLUS OVIS-PULMONALIS, Diesing.
PLaTeE XXXII.

Portion of right lung, exhibiting an advanced stage of the hair lung-worm disease.
The small dark spots show the youngest stages, the large patches show the disease
well advanced, while the large light spots are the oldest. A section cut across one
of these shows the depth at which the lung is affected.
PLATE XXXII

warm

auc
pipe RR

 

 

Haines, del.

A Hoen 4 Co. Lithocaustic Baltimore

SURFACE OF LUNG DISEASED BY STRONGYLUS OVIS-PULMONALIS,
Fig.

Fig.

Fig.
Fig.
Fig.

4
5.
6. An enlargement of d, showingd eveloping embryos in alveoli. In Figs. 5 and

200

STRONGYLUS OVIS-PULMONALIS, Diesing.

PiaTE XXXIII.

. Section of lung tissue through two small tumors caused by the worms X20:

a, caseous degeneration of tissue in the center of the tumor; b, the same
in the pathway of the moving, growing worm; c, cut fragments of the worm
(the pathway of the worm is interrupted between a and b, because the plane
of the section did notinclude it); d, a bronchus into which the parasite has
almost found its way; e, portion of a second tumor made by another worm;
f, nearly normal tissue.

. Section through an older tumor at the stage which has been likened to pneu- ;

monia, X20: a, tumor with fragments of worms; b, fragments of an adult
worm; c, eggs in segmentation stage; d, embryos somewhat developed ; e,
young embryos; f, bronchi; g, nearly normal tissue.

. An enlargement of b, Fig. 2, showing fragments of adult worm in the bron-

chi and alveole.

. Anenlargement of e, Fig. 2, showing young worms in the alveolzx.

An enlargement of c, showing segmenting eggs in alveoli.

6 the outlines of the egg-shells are not shown. Figs. 3-6, X90.

(These illustrations were made from specimens selected from a number of serial

sections which were stained with alum-carmine; the dots represent the
nuclei of the cells. AJl sections show the great multiplication of cells
about the points of irritation, whether excited by the adults or embryos.)

Fig. 7. a, embryo of Strongylus filaria, and b embryo of S. ovis-pulmonalis, each equally

enlarged to show comparative differences in size and outline.
PLATE XXXII

 

Haines, del. Viloen & Ce, Lith, Bilt

 

SECTIONS OF LUNG DISEASED BY STRONGYLUS OVIS-PULMONALIS.
THE THREAD LUNG-WORM—VERMINOUS BRONCHITIS—
HUSK OR HOOSE—PAPER SKIN.

STRONGYLUS FILARIA, Rud.
Plates XXXIV, XXXV, XXXVI.

The thread lung worm, or Strongylus filaria, is the best known of the
sheep lung worms, for the reason that at times it causes extensive epi-
zooties in the flocks, and that the worm is large enough to see when the
bronchial tubes are slit and spread open. From personal observation
it appears to be much rarer than Strongylus ovis-pulmonalis, and the
disease it causes much less extensively distributed as to number of
animals infected than that produced by the latter. In most: of the
American literature on this subject the disease caused by the hair lung.
worm seems to be ascribed to the thread lung worm, and no mention is
made of the former.

Description.—Male, 33 to 54™™; female, 55 to 80™™, Worm filiform, white, with
a dark hair line showing throughout its length; head obtuse, withuut notice-
able papille or wings; mouth circular, naked; unicellular neck glands quite large ;
cuticle longitudinally striate. Male: Bursa shallow, campanulate, opening later-
ally ; five sets of costes; the dorsal are trifid, the lateral bifid, and the ventral sepa-
rated. Spicula arcuate cylindrical; 3.35™™ long by 0.075™™ wide; short, very
thick, dark brown; chitinous portion a curved fenestrated conical tube; fleshy por-
tion a membrane, which formsa bulb-like expansion toward their freeend. Female:
Vulva three-sevenths of her length from the head; uteri symmetrically directed
auteriorly and posteriorly ; posterior oviduct becoming continuous with the uterus
near its flexure at the tail; ovo viviparous; eggs ellipsoid, 0.075 to 0.120™™ long ;
0.045 to 0.082™™ wide. . Embryo 0.25 to 3™,

The life history of Strongylus filaria is in general that of other para-
sites. In some way the young worms arrive in the bronchi, grow, de-
velop, become adult, mate, and lay their eggs in the surrounding mucus.
The eggs laid are not true eggs, for each egg-shell contains a young
worm within, a feature which is described by calling the female ovo-
viviparous. The inclosed young escape from the shell, and many of
them are expelled from the lungs in the coughing fits along with other
discharges. These young, which are scattered about watering-places,
pastures, sheep-yards, or corrals serve as infecting and reinfecting ma-
terial for a considerable length of time. Professor Leuckart (Entwickel '
ung d. Nematoden, Arch. d. w. Heilkunde, 1865, p. 299), kept the young
of this species alive for several weeks on damp earth, and observed them

-pass through a stage in which they molted or threw off their skins,
: 201
202

after which many died. Baillet (Colin, G., Bull dev Acad. de Méd., t.
XXXI, 1866, p. 874) preserved them alive in water for several months.
Ercolani (Neumann, Traité des Maladies parasitaires, p. 515) is author-
ity for the statement that they can be resuscitated after being dried a
year by putting them in water. The writer has kept them in stagnant
water for weeks. Ercolani’s statement is by far the most remarkable,
and accounts for results obtained in an experiment in which the writer ,
kept sheep for five months on a narrow dry pasture, supplying them

with water from a pump only. When these sheep were examined they

were found affected with Strongylus contortus, S. filicollis, 8S. ventricosus,

Dochmiuscernuus, and Tenia expansa in very young and old stages. The

eggs of these were introduced on the pasture from two or three older

sheep which were with the younger ones, or possibly by the young

sheep themselves, some of which were between three and four months

old at the time. Two of the lot were born and raised under experi-

mental supervision, and these were also infected. Strongylus jfilaria

was not present, but it was not discovered in any of the sheep from the

same lot killed at the time of selection of the experimental animals, nor

has any trace of this parasite been discovered in any of the older ones

kept at the Experimental Station.

Professor Raillet details experiments (Recueil de Méd. Vétérinaire An-
nexe, 7 Serie, Tome VI, No. 8, April 30, 1889, p. 173) in which he dried
embryos of Strongylus filaria under different conditions, and found, after
a few failures, that some could be revivitied as late as sixty-three hours
afterward by placing them in water. His success depended on the
condition of the embryo at the time of drying.

It may be accepted, therefore, that the young parasite may retain vi-
tality indefinitely, depending on telluric and atmospheric conditions.
From Leuckart’s experiment it is to be inferred that though moist earth -
and damp places are favorable for the life of the young parasites, yet
they are liable to molt and then may die from the loss of the older and
tougher external skin. From Ercolani’s and Raillet’s experiments we
may infer that the drying of the young parasite suspends its functions,
which revive again when the surroundings are suitable, and that the
parasite is in this state the most dangerous to sheep.

Preventive treatment.—The foregoing indicates that after a farm is
once infected the prevention is not an easy matter, for dry embryos
may be scattered everywhere. Although the parasite is more abundant
at some seasons.than at others, yet it may be found in limited numbers
at all seasons, and animals affected will distribute the eggs throughout
. the year, thus increasing the difficulties of prevention. All animals
which show the least appearance of being affected should be separated
from the sound ones. The water supplied to the sheep should be pure,
i.é., either taken from wells or led into troughs from sources which can
not be contaminated. If the sheep are allowed to drink from running
water, then all of the brook should be fenced out except where the
203

sheep drink. Dry pastures without bog-holes or sloughs are best for
the animals. As the germs live for some time in a dried condition the
old pastures should not be used for. young sheep at least, nor should
the latter be allowed to graze after older sheep which have had the dis-
ease during the previous year, nor should the pasture be overstocked
so that the grass is eaten to its roots.

Disease.—Verminous bronchitis attacks young animals, those under
two years being the more susceptible. Animals poorly nourished and
those already weak from other parasitic diseases are also more liable to
become a prey to this worn. Damp, warm seasons are most favorable
for the preservation of the parasite and the disease it produces. The
disease is most prevalent in summer and autumn, becomes less in
winter, and disappears in spring-time.

The symptoms of this disease, as in verminous pneumonia, are im-
perceptible in the first stages. Itis probable that, beyond the slight
but deep cough produced in some of the worst cases, but little else can
be noticed. The sheep may have difficulty in breathing when driven
or be short-winded. They may be anzmic, as shown by the harsh, dry
skin, dry wool, and pale mucous membranes. In later stages the
symptoms will be aggravated; difficulty in breathing, coughing, and
general debility, associated with an anzmic condition, will be the most

-prominent symptoms. Occasionally shreddy masses will be coughed
up, which, on close examination, will prove to be worms. This is a
decisive test of the nature of the disease.

The sheep has a fair appetite, but will gradually lose flesh. In the
last stages the bronchial cartarrh is severe, the respiration very feeble
and jerky, the cough deep, convulsive, and evidently painful, coming
by fits and followed by suffocation, which leaves the patient still more
exhausted. The nasal discharge becomes more copious, and contains
quantities of embryo and worm fragments. Owing to the diminished
respiration productive of anzmia, the skin becomes dry and harsh, and
resembles parchment; hence the popular name “ paper-skin.” The wool
is also affected and is easily pulled off, exposing the white, bloodless
skin underneath.

Duration.—Death occurs in three or four months either by exhaus-

- tion of vital forces or by suffocation. As the first stages pass unnoticed
the total time from infection to death is probably nearer five or six
mouths, The duration of the disease depends on the amount of infec-
tion, the previous health of the patient, the care it receives, and its vi-
tality. Where the symptoms are very decided the patients rarely sur-

vive. The disease is most intense in autumn, and if the sheep do not
die, it. becomes less intense in winter to more or less completely disap-
pear in spring. When the season has favored the development of the
disease and the lambs show severe symptoms, ‘the outlook for their re-

covery is very unfavorable. A large percentage of those attacked die.

.
204

Others fall away in flesh to a serious extent and the growth of the fleece
is retarded. .

Occurrence.—It is a usual thing to find Inngs affected with Strongylus
ovis-pulmonalis, and more rare to find them affected with S. jilaria.
When the latter occurs it is ordinarily associated with the former,
owing toits abundance, but it is easy to separate the two diseases. In
the beginning of the S. filaria disease the very posterior tip of the lung
ig affected, turns dark red or grayish, and has a solid feeling and ap-
pearance. From this the disease spreads anteriorly, lobe after lobe
of the lung becoming involved as the bronchi choke up. These termi:
nal patches are very sharply separated from the adjacent portion of the
lung, which appears normal, except that it may be infected with S. ovis-
pulmonalis, as indeed may be the part infected by S. filaria. The cause
of this solidification or hepatization (so called because it becomes solid
like liver) is the stoppage of the air tubes by the worms and the débris
they produce. When they exclude the air from the part the air cells
fill with débris and the part becomes solid. Portions of lobes elsewhere
may become involved, but more rarely. The anterior lobes often ap-
pear red and solid, but it will generally be noticed that in these the red
part is thin and not as spongy and resistant as the lobes in the poste- °
rior end. This state is due to the air being driven out of the lobes and
the walls coming together, producing a state of collapse (caruification
or atelectasis).

The solid lung produced by S. jfilaria is often covered by a thickened
whitish membrane, the inflamed serous membrane, which often grows
fast to the chest or thoracic walls. After the worms disappear, either
having been killed by remedies or from some unknown reason, the heal-
ing process begins, and the lamb recovers if not too much weakened.

Treatment of this disease is far more hopeful than that of the pneu-
monia due to Strongylus ovis-pulmonalis. It may be dietetic, preventive,
and medicinal. In an essay on this disease Mr. Stephen Powers (The
American Merino, O. Judd Co., 1887, p. 283) says:

To sustain the strength and vitality of a sheep already affected is exceedingly diffi-
cult, because the appetite is feeble and capricious. The lamb can seldom be induced
to eat enough even of the most nutritious tood, to make any considerable impression
on it in the way of betterment; and the danger in giving it by force stimulating
gruels, etc., is that, owing to its bloodless condition, the process of digestion will be
so illy performed that the food will do it more harm than good ‘by causing scours.
High feeding is of transcendent importance as a preventive measure; but when the
lamb has reached such a pass that vermifuges have to be employed, it is necessary to
proceed with great caution in giving rich food.

These remarks commend themselves to all who have had experience
with afflicted sheep. Keep the lambs up to the highest point of ex-
cellence and health by feeding and they will the better withstand the
ravages of the parasites. Corn and oats, bran, chops, and oil-cake are
all good fatteners, and should be given in proper proportions. Salt
should be placed where the sheep have free access, not only as a diet-
205

ary article, but for its medicinal influence. In addition they should
have pure, fresh-water once or twice a day. When the animals have
become sick good diet should be supplied. Asintimated by Mr. Powers,
those animals which seem most in need of food take the least, and if:
they do eat it may even be of harm tothem, However desirable it may
be to feed animals well as a hygienic measure, still no amount of feed-
ing will keep them from being infected when a season favorable to
the parasite appears. There must therefore be a continual diligence
exercised in keeping the pastures in good condition and the young
sheep especially from becoming infected. As the parasites seem to thrive
best in water, it follows that dry pastures should be preferred. The
danger of infection from pastures should be diminished by limiting the
number of sheep, so that they will not have to eat the grass close to
the roots, and by a judicious distribution of the young sheep on practi-
cally virgin pastures. Should a pasture have become permanently in-
fected from long use it should be plowed up and either cultivated a
year or two or allowed to stand idle or surrendered to other stock.
The effect of the cold upon the embryos of these parasites is not yet
known, and it may be that the alternate freezing and thawing which
they sustain is in the Northern States the cause of the destruction of
large numbers of them. Leuckart’s experiment of keeping the worms
in moist earth, during which time many molted and died, indicate
that a pasture would be much safer when thoroughly dried after a pro-
longed rain than before, and also that such a wet time would be more
dangerous for the sheep. A judicious selection of pasturage through-
out the year, together with a shifting of the sheep from pasture to past-
ure as the season and ages of the sheep seem to require, is the best
tiat can be counseled at present.

Medicinal treatment may be productive of much good, but is usually
resorted to so late that its best effects are lost. Medicines have been
administered with the food by drenching, by fumigations, and by
tracheal injections. Salt and copperas in proportions of from 1 of cop-
peras to 25 of salt, and of 1 of copperas to 4 of salt, the last mixture
being given in wet weather, has been advised (The American Me-
rino, by Powers, 1887, p. 285). The weaker mixtures may be kept con-
stantly before the lambs for eighteen months. The stronger should be
alternated every two or three weeks with clear salt. Powers kept it
constantly before the lambs until after the second summer. I would
deprecate the use of copperas for any continued length of time, for it
not only harms the teeth, but if persisted in loses its force as a tonic
remedy. In administering dry medicines in food much of their force is
lost, for they are very apt to accumulate in the paunch or first stomach.
Medicines given by drenching are more expensive in the dosing: but
more effective, for small quantities of fluids pass directly into the mani-
folds or third stomach, and thence into the fourth stomach, especially
if the sheep be thirsty. But few of the many remedies advised are in
206

the least effective except they be general tonics and stimulants. Many
advise the use of anthelmintics, but these are of value only in driving
off the intestinal parasites. Turpentine seems to be an exception to
this rule, as some of it is eliminated by the lungs and so reaches the
worms. Powers (op. cit., p. 283) advises turpentine and linseed oil mixed
in equal parts, a tablespoonful at a dose. Mr. W. G. Berry saturates
lumps of salt with turpentine, then crushes the salt, mixes with bran,
and feeds as a preventive.

Neumann (Maladies Parasitaires, p. 517) states that the following
have been recommended: Picrate of potash, from 3 to 6 grains per dose,
dissolved in oatmeal, water, or mucilage; a mixture of equal parts of
turpentine and spirits of camphor, a teaspoonful daily in mucilaginous
drink; a mixture of creosote 120 parts, alcohol 500 parts, water 700
parts, dose a teaspoonful; creosote 60 parts, benzine 300 parts, water
2,000 parts, dose a teaspoonful for each patient daily for eight days.
Hall (Veterinarian, 1868) says that he employed with success 10 drops
prussic acid (to be diluted in water) for a dose morning and evening.
Neumann adds, however, that experience shows there is little reliance
on these methods of treatment, and the administration is, besides, more
or less difficult. _

The same author states that success is less uncertain with fumiga-
tions which penetrate directly to the worms, benumbs them, and pro-
vokes a cough by which they are brought up and ejected. The sheep
to be treated should be driven into as nearly an air-tightshed or stable
as is practicable. Then rags, horns, feathers, hair, old leather, tar,
asafetida, etc., should be placed on a red-hot shovel or in an iron pot
filled with burning coals or in a tinner’s fire-pot. The intensity, dura- —
tion, and number of fumigations should be graduated according to the
tolerance of the sheep. Hither some person should subject themselves
to the same fumigations, or a very close watch should be maintained in
order to prevent the lambs suffocating.

Tracheal injections.—The method of treatment by tracheal injections
promises much better results, but should only be practiced by a relia-
ble veterinarian, who can oversee the results and take all necessary pre-
cautions. The method has been detailed in the Second Annual Report
of the Bureau of Animal Industry, 1885, page 284. It consists of intro-
ducing remedies directly into the trachea by means of a hypodermic
syringe which cause the death of the parasites. The medicines thus
introduced have an opportunity of acting upon the parasites directly,
before they are all absorbed by the mucous membrane ot the air pas-
sages. There is no reason to doubt that they may have even a second-
ary effect after their absorption if they are naturally thrown off by the
mucous membrane of the air-passages and the epithelium of thealveoli,
which is the case with most volatile substances.

The method of tracheal injections was first tried by Gohier in the early part of the

present century, after learning experimentally that considerable quantities of liquid
can be introduced into the trachea without producing suffocation. Delafond some
207

years after conducted some experiments to determine the absorptive poworof the air
passages. He found that mucilaginous decoctions and solutions of sugar or honey
are speedily absorbed when injected into the trachea, inducing slight symptoms of
suffocation for one or two hours. He also found that solutions of narcotic agents
and stimulants manifest, their physiological effects very soon after injection, and that
oils and oily medicines produce a congestion of the lungs which is but slowly dis-
sipated, and that even very dilute solutions of mineral and vegetable acids produce
inflammation, with copious secretion of mucus, giving rise to symptoms of asphyxia
and even leading to death. oO oa

Dr. Levi, of the University of Pisa, has recently applied this method in the treat-
ment of a number of diseases (Manuel pratique des injections trachéales dans le cheval,
1883). His experiments also tended to show that the mucous membrane absorbs very
rapidly, and is therefore less apt to suffer'from the injection of irritating substancés
than if the absorption were less rapid. He also determined that the injection of small
quantities of oily substances is not dangerous, the oil probably being emulsified and
absorbed. Finally, there is always a slight reduction in the number of respirations,
amounting to about three or four per minute, after the introduction of liquids, even
when distilled water only is injected. a

Without entering into interesting questions concerning the administration of med_
icines in this manner in other diseases, which are discussed at length in the work
mentioned, we find that the author has experimented on but one case of lung worms
to test the efficacy of the method. Others, however, have reported cases in which
their success justifies a detailed account of the method for future application.

The instrument to be used is a simple hypodermic syringe holding from 1 to 2 fluid
drams. The needle of the syringe must be provided with a removable solid rod or
trocar, so as not to become plugged when it is pushed through the skin and walls of
the trachea. As the needles are apt to break, a number of them should be kept on
hand. After the operation the syringe should be carefully washed in pure water, the
piston supplied with a drop of olive oil, and the trocar replaced in the needle.

It is best to disinfect by filling the syringe and needle with a 5 per cent. solution
of carbolic acid, or a 0.1 per cent. solution of mercuric chloride* before washing in
pure water. The disinfection, however, is not absolutely necessary in this operation
if the syringe and needle be kept thoroughly clean.

To administer the medicine first fill the syringe and place at the side. Hold the
sheep for drenching, and extend the head of the animal so as to fix and make promi-
nent the trachea, which will be felt as a tense elastic tube along the middle line of
the neck. The most convenient point for the introduction of the needle is at about
the middle of the length of the neck. It must be remembered that some care is to be
observed, as the trachea is near some important structures on either side—the jugular
vein, the carotid artery, and the pneumogastric nerve. Having fixed the trachea
with the left hand, the needle with the trocar is inserted beneath the skin, and then
an interannular space is sought so as not to pierce a cartilaginous ring. Or the
needle may be pushed directly into the trachea without necessarily avoiding a
cartilaginous ring. The unimpeded movement of the free end of the needle as if
in an empty space is asuresign that the needle is in its proper place. The trocar is now
removed, the syringe screwed upon the needle, and the contents very! slowly forced
into the trachea. Before the needle is finally withdrawn Dr. Levi thinks best to
wash it out with some pure water so as to remove the injecting fluid. , In withdraw-
ing the needle this might accidentally be discharged in the wound made by the needle
and set up inflammation if the substances introduced be irritating, How this wash-
ing out is to be done he does not state. It seems that a small pipette or medicine-

 

*The former is prepared by adding 5 parts by weight of pure carbolic acid to 100
parts by weight of pure water previously heated ; the latter by adding 1 part of the
corrosive sublimate (a violent poison) to 1,000 parts of water.
208

dropper filled with water and inserted into the end of the needle would suffice to wash
it out, or drawing back the piston of the syringe would leave the needle compara-
tively empty. The needle might also be washed out by removing the syringe, wash-
ing it out, filling with water, and forcing a few drops into the trachea through this
needle. This, however, would cause unnecessary delay before the animal is released,
and is therefore not to be recommended. The simplest method, then, to empty the
needle would be to draw back the piston, for the discharge of anything but the purest
water into the wound may produce more irritation than the medicinal substances
themselves. The animal should be watched for some time, especially after the first
‘operation, to observe how the injection has been borne, and whether any symptoms
arise which indicate difficulty of breathing.

If, as has been suggested, a slight incision be made in the skin before introducing
* the needle, and if a cartilaginous ring be avoided in piercing the trachea, the ordi-
nary needle with beveled extremity will be sufficient, and the trocar may be dis-
pensed with. When the needle has entered the trachea, a slight hissizg noise, due to
the entrance and exit of air with each inspiration and expiration, indicates that the
needle has reached its destiuation and is not plugged. °

The substances to be injected should have distinctly vermicide properties, with-
out being at the same time too irritating or poisonous in their effects on the animal.
Levi gives two formule which he used with success upon asheep. The worms were
discharged in three days and the catarrh cured: Iodine, 2 parts; iodide of potash, 10
parts; distilled water, 100 parts, by weight.

Begin with half a dram of this solution, add half a dram of water, and increase
by half a dram of the above solution each day up to5drams. Anotherremedy is the
following: Mix equal parts of turpentine and olive oil, and inject from 1 to 4 drams.
In this case the writer probably intended to state that the dose should be increased
from 1to 4 drams on successive days.

Eloire (Recueil de Med. Vet., 1883, p. 683) gives the following formula: Ordinary
oil of poppy and oil of turpentine, each 100 parts; carbolic acid and purified oi] of
cade, each 2 parts.

The oil of poppy, being a bland oil, does not possess any medicinal properties, and
may be replaced by olive oil. Each sheep to receive about 2 dramsa day for three -
days.

Six animals treated in this way showed immediate improvement and were finally
cured. Penhale (Veterinarian, 1835, p.106) reports immediate relief and ultimate
cure in two calves by injecting the following mixture: Oil of turpentine, 2 drams;
carbolic acid, 20 drops ; chloroform, + dram.

One-half of this amount may be given to a sheep and the dose subsequently in
creased if necessary.

Hutton (loc. cit., p. 62) reports fvorable results i in six out of eight cases by inject-
ing the above liquid, in which 1 dram of the tincture of opium was used in place of
chloroform.

This completes tbe list of remedies thus far suggested and tried.
The favorable testimony, though not abundant, is very encouraging.
There are many substances, no doubt, the use of which might be more
beneficial than those mentioned, but otis can be said of them until
they have been tested.

The dose for young sheep should be proportioned to the age and
size of the animal. The preparations with turpentine seem to have
given the best results: During treatment the patients should receive
the best of care.

The prevention of this disease is very desirable, though it may never
209

be completely attained. Ifa farm is completely free from it in the first
place, then prevention simply lies in not allowing infected sheep to be
brought on the premises. All purchases of sheep should be from flocks
which have shown no signs of the disease in preceding years. Brooks
which run from pasture to pasture offer a chance of infection where the
neighbors’ flocks upstream are infected. Strange sheep should not be
pastured unless they are known to be free from parasites. Feeding
and care to keep up the general health are essential. Careful separa-
tion of affected animals should be practiced, and the worst diseased
ones may beslaughtered. Treatment should not be neglected. During
treatment itis best to keep the sheep up, and after the course of treat-
ment is concluded they should be turned into new pastures.
23038 A P——l4
210

STRONGYLUS FILARIA, Rud.
PuatTE XXXIV.

Fig. 1. Adult female, x3: a, head; 6, vulva.

Fig. 2. Adult male, x3: a, head; 6, bursa and spicula. The dark line in Figs. 1
and 2 is the intestine.

Fig. 3. Cephalic end: a, mouth; b, esophagus; ¢, intestine; d, unicellular glands.

Fig. 4. Middle portion of female: a, vulva; 6, vagina; c, c, uteri with developing
eggs.

Fig. 5. Piece of skin showing striz.

Fig. 6. Spicula: a, the fenestrated chitinous cylinders; 6, the bulb like enlargement
of the surrounding membrane.

Fig. 7. Caudal end of female: a, anus; b, b, intestine; ¢, loop of the caudal uterus,
d, ovary.

Fig. 8. Caudal end of male, ventral view: a, intestines; b, seminal reservoir; c, the
torn edges of the spread bursa; d, ventral cost; e, ventro-lateral ; /,
lateral; g, dorso-lateral; h, dorsal; i, spicula.

Fig. 9. The same lateral view.

Fig. 10. a, female, natural size; b, male, natural size.

Fig. 11. Eggs showing various stages of development of embryo in the following

order: a, b, c, d; e, embryo escaped from shell.
PLATE XXXIV

 

A.Huen & Co lath Rattinieer

STRONGYLUS FILARIA,
(The Thread Lung Worm.)

Haines, del.
212

STRONGYLUS FILARIA, Rud.
PLaTE XXXV.

Portion of right lung of lamb, dorsal view. The affected region is the dark col-
ored posterior end. It is clearly marked off from the healthy portion. The dark red
spot about the middle of the figure is also caused by the worms, but it is exceptional
to find these lobes affected in early stages.
PLATE XXXKV

 

Haines, del.

0, Lithacaustic Saltimore

STRONGYLUS FILARIA,

LAMB’S LUNG AFFECTED BY THREADWORMS.
214

STRONGYLUS FILARIA, Rud.
PuaTtrE XXXVI.

Portion of right lung of Jamb, ventral view. This is the same lung figured in
Plate XXXV. The affected portion is in the posterior end. ‘The lung tissue has
heen dissected to show the tracheal branches and the bronchi. The bronchi leading
to the dark-colored affected region are filled with the life-sized figures of the Stron-

gylus filaria,
PLATE XXXVI

 

Haines, del. 4 Hoen & Co, Lithocaustic,Baltimace

LAMB’S LUNG INVADED. BY STRONGYLUS FILARIA.
INDEX.

 

 

Page.
Abdomen, parasites in (see Linguatula tenoides and Tenia marginata). :
Abundance of parasites.........-.....22. seen sarees peice wai s ciseaecedeus 9
Acari. ...-- eee evetiese tle tieccobeseueteeue piieee suse RR NLR Kic e'eibiee creuselorecia 53
ACH OBIS soe seco siaissa se Dee atic Sec aatowesane ewe eieaeee oko sce c cles ececeeens 53
ACATING Sasose oe cecmseteee ae betaws ewe veuwes Sasi: Sole ccisid wicicarsa becca tees 22
. Amphistoma conicum. ....--- 20 ceccen cecces cecece coccee cencceae ceceeacccecs 16, 138
Angora goat louse... 2-2 2.222. cece cee cece eee ee oe weve s etesacentades 50
Antelope as a bearer of sheep parasites...... 0.000. .202ee eee nee eee e ee cece 15
Arrangement, plan followed in bulletin.........- adisiaieeoessioclersa cee ceeeieee 22
ArthVopode ssisseiscs cisccedssa peceSeccestouelec es Seececes side siee se eecemcces 18
Ascaris lumbricoides .-.- 2... 2 ence ceccee cece ee coc nee ceccee ance cecccecc aces 16, 145, 151
description.......... Bile Gece cdexees pivacokewuease 151
figures........ Wie sisinsiceesioada ge ceccgecee decmat ecis Fb Shererates 154
ABCUTIS OUR ia acciers nr stincciascen aawed qnadke dhameecbeccsnwneanieweceewes a teaee 151
Ascaris suilla...-..2--. ee nnn eee dis eis deulee pene Sees i eweeeesemwanew seme ee ae 152
Balbiana Giga wee ssicacarscsieiacsak soda newnnsecces teecewedeseeeseoakeccizewecs 18
Bladder worms soescis aye saicis eQucie savececews: Gusset wera tree sk eeatuwaess 72
Brain, parasites in (see Cenurus cerebralis).
Bronchitis, verminous.. ...-.. 0020. 2-22. cece cece ee eens cee ee cee e ee wees 185, 201
Caecum, the worm in.............-.. Dd heat hae ate ara cars Selo e cere. 181
Catarrhs Wasa on: cea de-didcurcerdes ce yasia brane oaeca a serene semis Bind Seweeeccenswes 25
Chorioptes communis var. OVi8 .... 2.2. 22 n 5 eee ene ween ce eee eee e cence 53, 65
Coccidia .....----..----- giz (eis a cis ata ole Sve Hmaeinaee ysis mi eee esis eevee eeesee 18,117
Conurus cerebralis...-.. 22-20 ce0e cone ee eee = Goldiovajaiciolb clone wise emweeiin racists 30, 72, 83
Common scab (see Psoroptes communis var. ovis). ;
Coyotes, worms in.....-...----..---2----2 62 ci euSaleanamavnaynaeawiomlbierecinascees 14
CYystiber Cus: O08 Socceoscsuc css Gaicoewcs beh seeb een hae cee ndese Reece eacees 72
ALUTES oo sieiiaincin te ccyenss wee c eee eee e eee ceceee rea Dae aseeer 88
TM MUGON oc cciewciccercie Saeed ahialee We seem airattanwosineuee-ceeacers 87
Cysticercus tenuicollis ...--.-.--- sieoaities, «aojaee sraia vate dnisyae Syerevasises Soreicie Saisie 72, 75, 117
PPUTES s wicin sw anra'cinte sic eicid sac gmaitingisremerrie:s aisjecas i imcisis islets 80, 82
Definitions 2. cdcsceja ce swine Seisicce raisin wae cleine Sade Meta ate, ciee Saiki Werciewie ewicis.< 19
Description of species, contents of..-..---------+.------+---+ pisicieseeminsainers 10
. Diagnosis of parasitic diseases ..-..---- -- +--+ 22. eee cece cee cece cee e nee = 11
Disease, parasitic, mainly due to mechanical causes.......---.---.---- +--+ il
importance of early diagnosis.......--.-...----02-+------ 11
the nodular of intestines... .....-.---...02-cceeee cece cece cnee cere 165
Distoma hepaticum ..-. .---2+ ++ --- nore cece cece cee eee ee ce ee eee wee----16, 17, 127, 137
description ..-...-.---- Sul cuisaewimucsueredsoessaeewsussieces 127
disease caused by. ....--. -.2------ eee e cee e ee eee eased hoes 129
GiAPNOSIS Lecce ncccceccenenecc ese ueccose ee esses se 130
GUPATON ns cose sense ce eeerceeee sieesses sotindetnewess 130
PACHOlOZY cose sccccwsecesicieie scare cnecariene! seiciesie 131

215
216

 

 

  

Page

Distoma hepaticum, disease period of anemia......... ei eesede una enmee ses 129

emigration...... ita ataia wigvaucls wic'e cevnerserana 130

immigration .........2200.seeeeeeeeeee 129

loss of flesh.........-.. bene ameenees : 130

PLOLTOSIG 1: 0:o.0.2:5cieie'enip- o's seineins ec aeedeseswcieseicsel= 131

symptoms...... Wass esele eed eheeciwemeueecedeees cis 129

treatment.........-.- SESE Nee sews sere REESE Ss 133

AiQULCS iscises cece ceessr ase coswseeeswiscesesuacinss eee s ee 136

legislation concerning...--. 2.2 -..- eeee wenn ee eee eee eee . 134

life Ditstory seciciecwaewe tates sue seee dee «sewed wees cians wate, 128

OCCUITEN CE. aie cassie ac vacincis soos dese re saecvecewees oseeis 127

rare in United States....--. 2.2... ecceceseee ceceee ceccee “17

Distoma lanceolatum woos cuss vancen ves xesiessieniiseises oe scew snecceeda dese mae 16

AeSCri PtiONs ews se seecee cows ves eae eee tee corner ese ene 137

AGUIEGs: ssee sles. tdi Leas eiseew he seco yoke tease 140

Dochmius Cernuusiccoc cosa vereeenies Jacek oo ccxecewetwe's 16, 17, 22, 117, 118, 142, 145, 146

GESCRI POD scccics.c cee oes seed becsetaletetie ease eis 155

Aisease:Cansed DY iio wjoqessisee cee tew seem eeceet Per euesees 156

ATCMGMENb 3 2.55 cos cemielte Doe siti eee dace seek eee 157

MOUTES paces okey eae ceedeeee aoe de adeeen ebeeteseees 160

Vif I StORY ae sissies ai Sere: daninans bekle eec eee deine sn steamuieee® 155

OCCUTTE NCE. cic He ocioe tie es sie skuie towel tcceedokce aie ses 155

Dochmius trigonocephalus ..-... 020. 2-2-2 eee eee eee eee cee nee eee eee .--.- 156, 167

Wd OG iiassi2 sede ah sipsier wie ete erersind eee sieeiiOe teecicraie 155

Life: NIStORY sic etescrecio-wteicscieis scinicis aciseienuieamane cece 155

Dog; asia beast of Prev scccceJecceceeces costa ced Gee cee sede eeee siemeiciecen 14

as a carrier of dangerous parasites 14

Dochmius trigonocephalus in ..-22.-------+------ 0+ @ cidnve te aeedaieink sects . 155

legislation: cOnCermniNg 2.02 .xc2sheeusecies sacs caes eocaeeet cea teense cae 78

parasites of, common to man... .... ------ -- eeee ee cece ene eee eee ence ee 14

BHEOD vicesicwrcisiers Scie ses cad seneeeWeweweeee pees ee 14

relation to sheep husbandry ......-20. .2 2-2-0 eee ee cee eee eee ee eee nee . 13

TENG CONUTUS IN eres, sess celew Seem veiseemaeecss oe ceee tess cred eses eee 76, 86

Tenia: CUCUMErINGE IN sicie sas woe ove s said sees weissiesisis oo os secre ee eeeees te 76

TONE Mar giNata ID Possies ves gee veer eee terewawecins Gee exe occees sees ee _ 76,86

TONG GOV TOLOAD, oes coeose sean eceneredsemaebas Steadesss veeeee wos 5s - 76, 86

tape WOrms iN ..---. 2-20. 2 eee ee eee eee ce eee ee ee eee eee eee ell 4, 75, 76

intestine... .....-. 2.566 eimieramaereielatayahsjeraieertiwiio ae eeieSisisiaiels 14

and in sheep .. -------.. + +20 2-22 +e eee e ee ee cece ee eeeeee es 76,86

tréatmentacesssesicdas nets tn ccce tees Leesieetcn meme cae soe seeeeew sae 77

PLOVEDMVC sosd cccece see cws cane says cone es hows ween ee seme ena 78

varieties of, liable to infection .... 22... 6.0.22 2 oe neces nee cece cee 14
Echinococcus (see Tania echinococcus). f

Embryos, conditions necessary for raising........---. 22-22. -e eee eee ee ee ee 11

External, parasites... .2)c.0.0ss2c0es sees veewsewsarawer nee we aed see se we cee a 18

Feeding ...--. ---: .---00------ altace suse see ten cement waists wala eeee cs 13

PIWKGS saps sees secs erenestace does seeeesecstiasi coma twa secmste wee, tease nes 127, 137

Foot stabssans sess excees vdawesweeetisesion sacaea smametimaeseegse se eucieaieincisce 65

Gadfly (see Gstrus ovis).
Gid (see Tenia cenurus).
Pale@wssers. 2c sions sic soe ak sees seas the sma Seek eaiioee ces ers ewes se 30, 38
Goat lice (see Trichodectes climax and. T. limbatus).
Grub in the head (see (istrus ovis).
Head parasites (see @strus ovis and Tenia cenurus).
Head scab (see Sarcoptes scabiei).
217

 

 

 

 

Page.
FI OOKC gdcederuene soon sneneoaeee wdioteecenieeareaae Srateora Giaisaene Gets ares 185, 201
LUSK scaisicweiaccnctiwiecics eeaeetd eneieanaiee vesteectieee sewer eectbasssaeenccacc 185, 201
Hydatids (see Tania echinococcus).
TUN trations a2 2 sccrose supysics es caw caine abst Scee Sted) sede sicicee aver es seeeeawses 10
material for.....-.....- Updacpaweedineaiccheveoareaseaeieeaae meas 10
PULPORO2OF eos osigcac's Sctevseciesainieiaicavaceand ddan eceemenedoacaces ches 10
Infection, how secured in experiments... .... 0... 2-2-0202 eee eee eee eee eee ll
Injuries, how effected by parasites..... 22.0.2... 202. eee eee eee ee eee eee ee 1
Intestines, nodular disease of....-.-..- toe ashe Cae Moeact onus leweting 165
MOM siarseey slosie,etaae: oetdsatieeconee hawond seteenectescecee ssueteeeeeaes ; 53
INSECIS secede cesdced veleeecets! ctr sGGciew ame Cebeveeeonecers accu est aoe 53
Lime, parasiticide in manure...... 0-2... ene eee ee eee cee eee eee eee 13
Linguatula tenioides......----..-. ald late, jg/efeictotenslake ler quis felerovetn io sinless rarcrseeias 14, 16, 69
GESCLIP lO Ms cicieiciscls 2 eles gues cows sialenignese see ceeeeneos 69
Gisease cansed DY s..cecccssns cies vaca ciaceceweecedeenss 69
MP ULEG) vsene ve bse See sees geste keseeeNsonss omomaeeeace 140
life HIStory <accscas eeciciseie sone ane sees saeeeeeese cers 69
Linguaulorhinaridn<cosseunsesaweneanecs candice Saae aes eos vee vesesseemecess 69
List of parasites described...... pi hae cee eter a eaectan ahah yctatessch cy chk hh hee 16
external parasites..........--- pyeretia fe secon ete ctwc sews eves See 18
Liver, parasites in........-..--- ence ae eat 4 eau ache Melee eed wea were eects eae 127
Live’ POtssse sec Keseeve od tes eke Veee Slee aeeeaeed wecee sted vets eSeee odes 127
Liver fluke (see Distoma hepaticum) ......--2- 2200 eee ee cee eee eee cee e eee 127
(see Distoma lanceolatum)......---..-- Suscese Mare be cee tees 137
' Lombriz (see Strongylus contortus).
Louse fly (see Melophagus ovinus).
LUMg WOrMS 2... 2-262 noe cee nae nce co en ae neces ene enen comme teres enenee 185, 186, 201
Cia MOSiBy cine aiee SSae-aeehiaes Bane Mme ses damien Nase sesesbieg netics 186
BPCClOS: OF. hoevccis,evousiseissea’sialavnie soins sajeraiaie'e etmciancig Sine babe Sia’ous sibiont 185
parasites of the Old World....-. 00.2.2. 22-0. 222. nee ee cee ee cece e eee 17
Lye water and whitewashing in scab.... ....------ -.00 eee e tee eee eee eee — 122
Mallophaga, ..- 2.0 222020 cece ceneee cae nee cae wee seen cnne ceemes cecene cn cecces 45
Man, parasites of, common to dog... ---...-- 2+ -----e cece ne cone serene coe vee 14
BAEC Peicais cweics daeaimeneuweromecieemeaas cee eeeesy 16
tape worms in....-....-....---- Dic wits bas OAS Rie Sa wrataasatel@acaisreteie ars 14
ANG Gh6SP css veces ee eree ce seamecosecee a saisaidierceeie sie 87
Manure, destruction of embryos in...... 2.22.2 22. cone eee eee cern ee eee ee 13
economic management of...... 2-2. 2-22 ween eee ee eee eee renee 12
mixture of, with lime..-.-. 1.222. .-- 222.02 eee eee ee ce ee eer ee 13
source of parasitic infection........-..--.-2+------+ e222 eee eee Beieis 13
Measles, in mutton (see Tenia tenella).
Measurements, tables...--. 222-2. cece ee cen ene cee eee ee ene aGitew hadicte sosieis 23
Medical treatment...... 2.2.22 cee ene eee cee cece ce eee cece e cote n ence 15
Melophagus ovinus..---. 22-22-2220 ene en ee cee eee cece ee concen teenies centers 16, 39
diséase caused by 7 AL
treatment 41
experiments with 41
Figures... 22. 2 o eee eee eee eee eee eee ee cet teen tenes 44
DADS OLscd-cécLewewe decwdencecetece ess sare Sem eiepeeeterctersats 40
life history ......----- 22. secon e cee ee sttscynie wie ouainisieteererals 40
OCCUITENCE... -. 2. 2 we ee ee wn eee cece cee ne cee ne nee e eens 4l
BOULCE . «2 ee ee ee ee ne ne ne cee cree ceee cece reece scene cenees 41
Muscle, parasites in... --..--. 22 ee eee ee ee cee cece cee eee cee cee ee cere ee 87
Nodular disease of intestines .....----- -. 2.2. ene e cen cee cee ree cee cee eee 165

Nose, parasites in .... 22... cece cece eee cece cen nee cone enee scene veces cere 25
218

 

 

Page.

Gisophagostoma Acutum .- 2.2 a. cone ne ne ce nn ce nn an cece cone ene ene cewwen teccee 168
Gisophagostoma columbianum........----..-..0--6- 16, 17, 20, 21, 22, 118, 145, 161, 162
COSCrIPlOD ..ic5so52) desewece hacen dase sess come 167

determination of adult.................-..----- 166

disease caused by..-..--.--.---.--- 2c ee ne ween 169

GUA NOSIS: 3.22c.gie ee sievsvere diene cig ested Sele ees 172

pathology ...-.----- 2-2-2 -. eens cen eens 169

prevention .......--..2. 22-22-20 eee ee ee 173

distribution 2222665542244 ccewesededietuene Gane ce 165

FQ ULES socio oe uig oe ce sce ening ee aie co sew so 74,176, 178,180

investigation concerning -.......---------+e---- 165

MfEShiSbOLY oi warss Geice Soe creeeecee se nuwestas neces 168

OCCUTPENCE... swine: secre eecceseeces drole bh nisi s . 168

CEB US OVS soak Se eae ends Saas aeiee eeeedeaweweteeciesueisleemmaesmess 16, 17, 19, 20, 25, 85
GESCHP IO cccdee igh as He Se eee este ence seseracusestetanace 25

, OF Vai vitks asdcironentsd: sca sae sees se catisemeweeeameeess 26

OMOCES OD BHEED srsjeiorss cask Sticeitereminsn eas sewienes cere einerbinecinalow conte 27

POUT ES wicca csareraeae ma ciceveasdele au oo cect acbasnene teat stuwereslaweeOdy 00,00

OCC HERON C6 iin csearsisareciecsace-cme cmc oe wena cn wee cum seblabaneccmeeecse 30
Pathology = seca sasyorace aidaed soudeciercawaeceoe Foemeeceses sods 28

CLCATIICN E2555: ais as. cc.e pou <a anresaae wie cei ersasivaemasace vice. sen cals 31

surgical ..........- Deadman cat earneseeceieSucis cemis: 33

Pa perish Wass cuccinn sss J ehaieadceeacedecdiceieus ecdavere Sains Se wbiaiaiaicie MES 185, 201
Parasites; abundance, «.s)s)- occccacons doc cae cence aacesneeeaecsosaue cosa See 9
ANIMA saecccciaeisieiseibaiecémaedie tines weenie neces obed socawe eecneaces sets 17

common to sheep and dog..-......2. cesses eeeeee ene esis eases wal on 14

external, definition of... 2... 2.00 ceccee cence cane wenn eecee si 18
GEStructiveness. . ci ceeccine vducge eenece teen eaas vaates tweseeees 22

how sheep become infested ..-..-.. 022-2. .e00 ween eee eee ee cee eee 19

length of time of development... ..-. 2. eee eee e cone cece eee eee= 20

OC ATION sete coe ees neces Saeed cada do shetbeeecews west seeesee 18

Of 7G SKIN a eiece2 oie ape cece guises So Ss Sed oe bere ees SeseR SEES 39

seasonal appearance.......---- 22-2. cane e cane cen eeee ; 21
Veretable cece creas cciemesubeeecct ba deeetiaes cee eews s éaeeee wees 17

Parasitic diseases the chief source of losses 9
Pastures, as a source of infection ...... 2... 22. wee cone een cee eee cece ewes 13
CATO! Of. isles etee we cecdaweass cateen <cde eebhewwsetessninrecwedetece 13
Pentastoma denticulalwiiiecacste eye sckaeneceweecneses dessas seeks esecees eSihsuers 69
Pentastoma tenioides....... fetvdecrrasBrs aise Sab aineeytelaictcereratbcnes awe cbinvee Balak steel 69
I GER os tales & oa aie we teens Beta eee ck tas waemene eeu owe eee ay 39, 45
Pneumonia, verminous...........-2- .ecee ba cet a aaah Rad endian: we ba So aes 185, 186
Psoroptes communis, Var. Ovis .... 22-2 2c wen nen ne cece ce cece cee e ee ceenes 16, 17, 53, 56
disease caused by..... Siem dled gums wen aden Adaemvece cesses 56
PCiaPNOsSex2s52segaces see see w seek? Pe jaerniueeuve nests 57

Cifferential x. scenes vecsenswscedesessase 59

Patholopy «seewaeoeis cseces aoc cews aeedeesedeeests 57

PIOSNOSIG ccc eciswed secisicicee: sasews weareons cess 58, 59

source of contagion ...-.. --.2 -.2- eeeeee cone eeee- 58

SYMPtOMs Of saz svcassse deainwar sees coed sacice ewes 56

treatment medicinal........--.-----------eeeeee 60

preventive 56

APOUTCR soisce cic weuesia a) seuss cesses sawiewe abee's aes 66, 68

legislation concerning ....-.~----- .---00-eeceee eneeee ee 64

Purchasing sheep, examinations in ......2..... ..eene eee eee cee oot cacede ses . 1
219

  

  

 

 

Page.

Rabbits, not infested by parasites of sheep ...--...-.....-00. e006 Sciaiawisrsiciee 14
Ranges as a source of infection...... SoS Saiiircieiaree Madlscis/ am aimiain Wars asiesciene. sient 13
Walting. osc) psec geccdaed daw aeesemacues age iciSisi bainieinacaisjariemenieincie wieieisicciatie 13
CAD teen cat etoeddosverumacmetmanacious Mekicdadecc cen cape see wameoencciaease . 53
general description of ........----....-.- Picci ceeu ecard ede et aveion® 53
WMNSOCtS sa cSneeewiic ctecance ewes deal ecasmnnceoeceeeec sees aaa aielainiae 53

life history .--.-...... moe teeese 53
white-washing and lye water ..--.-.....- 12
Sarcoptes scabiei var. ovis.......... ib Savers cyavaieie wiciitahereiateyal ote seieiomemieeteneeme ss 53, 54, 56
MOSEL PEON a2 sie see wc sonceue cai lenls euecile sebktsveneeeccas 54

disease caused by ...2.- 2.2. eee en ee eee cee n ee ences cece cece 54

diagnosis... ...----- ..--0. eee 56
prognosis....-.-..----.-.--.-- 56

source of contagion 55

TPOMUIMEN 62 os .snceidicissgermerioracuysiais Seawiew: cen eeneaeeee 56

Sclerostoma equinum 2.200.200 ence cece eens cee cee cee cone cnn e ene ence cen ee 161, 162
Sclerostoma hypostomum .... 222. 2-22 22 ee cece ne cee nee nee cece ew ee cece 16, 145, 167, 168
;COSCTIPUlONY joie 2 cannsisracte: rome Haebis wee cee eee eee 161

ALD UP CS sei aia ia <'p'era ssie'inin ie marae ectear cise Sate sy cmte eerie 164

MPS NISbOPY” 6. aici esaptacie aire sue Neste Seepiscweweete wee 161

OCCUITONCO so 6):5)n\ <is'veieretds 3fe'es see ce eeree eee urases exes 161

Sclerostoma tetracanthwm .... c20. cece ceceee cece cone cece ween cee cone cence ees 161, 162
Sheep grub (see @strus ovis).

Sheep industry, value Of once seins ne oe ce cin ce vicnmes semininn ovine ceee saa ceceeesns 9
Sheep louse (see Trichodectes spherocephalus).

; red headed: sce. cnewenteetzsescscanwsesasocen sdecmecseeseeses 45
Skin, parasites of ....--...-....---.-26- JWlesieiei Scale UNee KwRe ese es coeenesreed 39, 45, 49
Sources of information, recognition of ......---. ----2. +2. 200 eee eee eee eee 23
Species abundant in United States. .... 2.2.22. 220. eee ee ee eee eee eee nee 16

American and European compared ....-. .---2. e202 ---e-e eee eee eee ee 16
AOSCTIDED) ai-).):<: sas weal secieesie aS teseeie aune dapsie) sieislectestete ecuscerctes 17
Gesteuclive cs: ccciecc ceascierivei aww wreisiajsio sraislaiste vielemipls Setiduwieweseeeeteewda 17
not in United States ...< .nseesicresweciesic some cawieee ceeskinaseeweos ames 16
of external: parasites seus sacs csismne veeeen sacoee crs seeeeax sees es 16
rare in United States. ........-..--22.-2----seeee wivanmeseeeasagaesias 16

Staggers (see Tania cenurus).
Stomach round worms (see Sirongylus contortus),

 

 

Strongylus contortus ...... 22-22. -0---0- seaeerinvesees 16, 17, 20, 22, 117, 118, 141, 146, 202
MESCLIPLION: cesciecsis secices. casi sessiew eee seM esse CHS ee de 141

disease caused by : 142

treatment 142

PPUTEBiecicsi: 62 ok casinsees ncn cue aoe erase 144

Jife WISbORY: c.ccisrjosle.cdieren teeemteeseehes ce kuimeisciee res 141

the lombriz disease ...... 1.2.2. .- 2+ enn e cee eee cee eet 141

Strongylus filaria -..2200 .2 2-20 cece ee cence cee ee cece ee cee tweens tone 16, 17, 20, 21, 185
‘ Gescription .. 02. 222.2. cee ee cee teen ce eee cece ee cece 201
disease caused by.......-2.2- ---- cece ee eee ee eee eee ree nee 203

duration...... fegeseeaas He cid awiardisinird a sisi Seiaeies Weigelt 203

tracheal injections for........---..----------+ +22. 206

treatment, medical...... 2.222... - 2. een ne eee ees 205

Preventive -..- 2-2. eee ee woe e ee enee ence 202, 208

AGUS ci ocvcacuscmaeevswoccweascestees wee cvewne conee- 210, 212, 214

OCCULITONCS wets sisieieuicarsaecwsenacccsce sVavecelbreleve Sietoleiatcisjara eicwwreaio 204
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' Sirongylus filicollis...--. . pemsdunceotiehaba: ddomeemesotenes 16, 22, 118, 145, 146, 149, 202
description .......- Sriram eect d tee Coad autE ater nasa 146

figures....... wiSce seine ShmGoueeS soa e case msumee aesecne's 148

Strongylus minutissimus in Algeria 17
Strongylus ovis-pulmonalis ........--+. Jatin Mehr sees 16, 17, 20, 22, 185, 186, 201, 204
description ---...-.-------- eee eee edust beer cartels 186

disease caused by ...--------.- og te ge wvnemee came 187

diagnosis ...... 2.2 ---- 0. eee cee ee ee eee e 187

Pathology. veiccceicnascviec even secincwne since 187

PIOLNOBIS: .<. vicien eee cevisgecescciawsace oncewe 187

source of infection. ...--.------2--------+- 189

treatment medicinal. .:......-..--.------- 190

preventive. ......---.----.----- 189

figures -.--. 020. cee cee eee wees eee eo 192, 194, 196, 198, 200

life: History socee.cics ckoicaveceee wets wert. cces 186

Strongylus rufescens a 8YNONYM. ..---. 2-0 ee eee eee ee ee cece ee cece eee eee 17
Strongylus ventricosus ..--2. 2-22-22 s-eeee eee woes seeds Seiler 17, 22, 118, 145, 149, 202
description ......- iitaielaleiaiaie ainiews sec cupeesebaneweesimase 149

Fp ures ote esiews veceiadeu ocean yew de eases seiata ease Vaiwiois 50

new parasite of sheep 17

SLUTEY so ccse ce cacemesets sconces ua Seales sein awiois eemacacieccsmmameces cates &3
Symptoms of sheep infested with parasites....--..--2.---.------ eee eee 11
LEMIGAOUEOLE .¢. 200 che ctiaetice atecee eaeeea sos measse boemisieeaaieeSaececceccr 89
LORD QUO acne tad sioieis sewn dioetienininide- ase wdeiec Ges end geese $8ecer imeisers 89
Tenia. Benedent, xcssaciewsis, wen sceaweccceeesewaed-cnos saad Scueeetineeaeecieme< 8
Tenia centripunctata...-2. 222-2 cence wen eee eee wee nee bea hence ate Sad 89
TONG CORUPUS cnee veswceasiesas dene sees ves eee cone -eeee eee 14, 16, 17, 19, 22, 72, 76, 83
CYSbiC LAGS «cos .% skemwise eee eaewscievieeed seececes ceed wes cscs 83

disease Caused DY sas sesaccacccsnsmeacis wane seiceeee sie acbineree a 89

MiAGNOSIS cxccscnceeexerecpacicws waewae ceeceeseensecs : 85

duration of development... .........--. ..-------+---- e4

breatmenticcc ise cise csemed weeteseeeinw -omsisteieculecos eye: 85

AOULEBi: scsidaisiaict smeanet sdeeasesessereat mdiekke sbewesceseeases 86

life: NistOry wsicnesce cemaw senda cededcesweaeeh dex ska ueccksaees 83

method: of infection .x:scsens ces wesiawos! Weipene dus cee see a wena 83

Tonia cucumerina .....0..2-ee. eee ne eee Bled eset eaated uy Sue seeeeoune wer 76
LONG CORNOCOCCUR gaia ssc wivinis: sjajeis ede e see easeeededee deicieice Suse scaw wees 14, 16, 17, 72, 86
AMPULES. siocie/sswianivnid ates hearcs Raciwa &eoeeks ote cake vewees 83

PMMA D seizes ers ire sp atnoaichsiatsltes seme eee SA ee aevoeies 14

life DISbOPY: aioels Sete aise ese smaeeulvewaaraegas acces 86

CPCAPMENG 2. cacdiere amocren sueeitocewbivencias Sasi aaehs warels 86

LENT ALPONSG: io caisrsaie sistas ois oekacate Ss deiwielals aaisicine alee es 16, 17, 20, 103, 113, 142, 202
GESCHIPLIO Decweiyxicwmiersleebinkvetaeesine Scatter enloicieg sisted enka Leow 113

disease Caused. DY -<sice ecnewe ves see eceedd sows cece sees bares 119

ASN OSIG sesec asec sccaesaaes see Mees oamaciewiege.a 119

OCULat ON saved odode das, Beeeeeeeouesas pad Srcjo erat é 120

OCCUITCRCO: scstcns euxceen seeeeeheeeeee see stoeds wat - 120

PTOSNOGIS dc ewe ieee. cles see cGetsheneld seek eaes 115

: LOAtM ON tsa qccid cites cow teeawe we ewer enokms aoeeeaes 120

distribution ......2.2......- a6 Kawase KRRGe paReewKemers 16, 17, 103,113

experiments with 116

AP UTCB wae on ote cases gas Bec tem eee veatnee eee ameeueeeas 124, 126

life History: ve smwuee secs aise eaejemswscke vere ceedacereee sete 116
 

Page.
Fenia expansa life history summary ......-.....-4-- alecee salar eicleneiereced sees 118
OGCUTTENCE ---.. 22-2 e eee eee Palcisatowiee arse Oirees nein es Semaitee ees 115
Tania fimbriata...--. 22-202 2-2 e eee eee eee ti Di diieiatayinia a eres eieldzeinre apni ees aretsie © 16,17, 89
description..-..---- dboiteituiexserisicis GieSiwiniedis wie sane welsoenmes See 91
CISGASE CAUBCD DY «nnn ncacriciecccicinice esis cdewcs scwelcteececs 95
treatment, medicinal... ..........22-- 2-22-0202 seen 98
PIOVEMNULVE: 2c .cce ccc ccindeoetencmessencess 100
distribution ...... 0.0222 seeeee wees eee eee ee Roe e ames ee ues 93
experiments ........- J didi bewiew sem Seaweed wecwanmesareseiosis 103, 105, 108
_ figures... 22. 2.2 eee coe sas sini a Seale oiojei eS Grit re wiaisiewiaateswelwintaicige 110, 112
investigations concerning....-. 2-20... - 2-5 eee e ee cece ee wees 90
Vife Wi StOLYssrevsicias wise es seis so pitas Bea agp ba esas Bie cate ererets 94
objects of experiments......-----.- 2222+ eee ee cee eee eee eee 91
occurrence .......-. ote bla (s feiaie Vets inte dita lols wre Wisiainatel warerSrarerececia) waste: 93
post-mortem examinations for finding...... ..-.-....--.---- 103
results of experiments..........- émayayeiatense mistewineeew ceca 91
Tonia Giardi.....-.-.0 2200+ eeee- olgieial dans SaaeaveeRienie miveiew eis ici iewenettss 89
Tamia globipunctata ..--..----2.--0+ 20-0. J atstaraldr aceasta ae wetnem neti eke 89
Tenia marginala..--.5..6-- Licences em ete seaes 14, 15, 16, 19, 20, 22, '72, 83, 86, 114, 117
CYStIC BTAGO.. 2... cern ee cone seme ee cee e ne teens cone nee renee 72,103
disease caused by -...-.-. 26 cone eee eee e cree cone cee eens 72,76
diagnosis....-....----- 4 aicisisiesnaiciae'D caipsisiceeecwewen : 76
treatment .. 2. 2... nw cee cane cone ween cece cone ce eee 77
distribution ..-. 2.02.20 2 eee ee ee cece ce eee cece cones 72
ADULTE ais, o wiser s rojacnarpiswiaiaisrsisiwie Gioneia miecisinisieisicie dipaie Swidieieee BSS Si 80, 82
PIER cae seitreneraraparctovers store Aweersetecutwetce eacewceteedciee sae 14
legislation concerning...-.. .---2- --- 202 eee e ee cence eee eeee 78
life history of adult s.ccccccccgicicinct eine semimneciscietic tess aemaie is)
OCCULTONCE vicisccicicicie: cirsiceniew. ces eens eisreee stews SnawenaiatS cia 76
Teenie ovidla ..- 2. oa cn ee concen cece teen ne cone came ee nee meee seen ceweneceees 89
Tenia solnennniaks aieiee xialnial Walters), iareiarstsietatoteelecnapeiedy  barcterew haw tisieie s beieiea se ser 89
Tenia plicata, wrongly identiGed? PI SLOOP sisi ecogrrccpugeieccce aces scece es “ 89
TONG BEV TOLG vas 250 oi 2ssce nates cl serene sees aeeces ae pitciuie Sieteinatele Saas am ae 76, 86
SDB RAG LONGUE copays erarzixpctarm'siateioss pielanicta Nisjastieiarecieie-daseie Gleigieise Gi bee Soe eee sees 16, 72, 87
FigUTeS 2... ccc e cen e neces cee ee nee ce eee eres tees een eneee 88
TD MAD - oes cscsic'saarwecarssecisinnecines/geiievenie cine snes sinees ere sesics | 87
Toewia Vogti .---. ------ 22 ce enee enn n en een cee cee nee eccee nce ieoaeeee” 89
Tape-worm, adult (see Tenia fimbriata and T. expansa). ‘
disease (see Tenia fimbriata and T. expansa).
immature (see Tenia marginata, T. cenurus, T. echinococcus,
and ZT. tenella.)
occurrence...-.. ----.------- 6 pane ae naw wes onan cecees 72
in dOgs «.-- 0-22 eee ee cee cece cee eee cere cone cere nse ece ceeee 75
in Hropean sheep ..--.. .----+ ---- 220 cece eee ee cone cere cee eee 89
the broad..-.....- ocr e cannes terre anne rece e een wene tecee oe. 118
fimbriate ...-2.- 2-2-3 penn ee cece cn eee tener tenes new eeee 89
Tracheal injections-.-..---- seigiebieiev sine Soa ee AAR Giclee cals o mece sem aetieemslemaine 206
Treatment, empirical...--..----- --2-0+ -+---+ +++ Ge swe cesta meas oumememrasee 12
hygienic 12
medical, of large flocks -.........-.---- D5 As ye straiarsichd aiavauintere cee 12
* — Trichocephalus affinis ..---.----2+e+e+ cece ee eeeees Saaieenes "16, 22, 117, 118, 142, 145, 181
eESCTIPLION .. 0.0. caneee cacces ceeeee cece eee e nee cet ee 181
disease and treatment... .....22. 02-22-22 eee eee eens 182

FiQ*UYes....-- 2-22 -se eee epee toner sene cree eens serene ones 184
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Trichocephalus affinis, life history ......----- .cceescecces ceeene enue ence cere 182
OGOUTTENCE weyeeaapearamresiieiticieets acin's eeinwee de sees cae ces 181

Trichodeotes olimaw s< s2<2csagescexwieceee snes vice eeces Gece seece cesses ----16, 49, 50, 51
description ...2.. 22... 2 2c. cone cece ee cone ene ceeee eseses 51

d AGULES. c2's ceceeowsrsse dewesesemicie'e sere sisson aig wineieeceres 52
Trichodectes climax var. major. .----- +++ +--+ +00 tec peiaidiceedaetecinisease seein miclere 51
Trichodectes limbatus 1... .--- ---- -- 22 enon nee cee e cee e tee ence cee wo wees cee eee 16, 49, 51
Geseription....-2 2... 22 cee nne cee ee cee ee cneeesceees 49

disease caused by.....---. seine hlaie laG aieiein sie biete ec'eir 49, 51

occurrence ..---...- eeeneiees Seceows seaeeccs, 49,51

trEatMON baie cweeces sae cocodenecveccvsceracesce 49

APULES scpscwins siewew nes see's Wear Rabe deeerevewenserces 52

Trichodectes: vi ssccz sence ses se esccciseeseeinee cises seescaesee avemeseeceice wis 45
Trichodertes pilosus <nicccs escsicsaa-ssisinwe seiveee sees was cewssccenaceeasn asic 46
Trichodectes spherocephalus ....-.---. +++ ieee ese we ee eerie see » eon ---- 16, 20, 45, 49, 51
GESCTIPLION sacscercsicmies sues sone cceecwectwenecesinis 46

disease caused by ..--..-- 2-2. eee e cece ee cone coceee 46

AQULOS, scjer.escniee steece sees es Serer asta ciarelsiaiale 48

life: history? saree vans cecceesedecsees Secure sparereicjetarare 46

/ TreatMeNt aso -oweiczce wsscivsadeces use cuioncaeiewaes 49
Trichosoma papillosum ...--.- 222 eon eee e eee ne tec eee cone cece e ene cece ee ie 147
Tuberculosis, an uncommon disease in sheep. .--..-----.- isteieusiaasee deme : 165
Water a a0uree Of TRICO cccres swe une neeeen bab maeeeecen aco nium yee ome 13
most suitable for drinking. ..... duMteeshrsacisiae sii ceemen seceeeecede 13
Whitewashing and lye water for wood work in scab .....-...---.---------- 12
Worn, intestinal round ....----..----------- eee ee eee e ee cee nee cere eens 145
Tangy, Hstiobas dice ercisisiere: sige sscsog= $sie'5'2 <in eho. gieinivisie'sise ee Hele ieiststs Mewieeieneers 185

the cwcum (see Trichocephalus affinis) ..----.----5+-.--0- 220+ wens 181

the hair lung (see Strongylus ovis-pulmonalis) 186

the large round (see Ascaris lumbricoides) ...... giles eas else: ° 151

the stomach: TOUDG sascicie vies sisiaia ee cccssciccisicigs saccine sniines eecennss 141

the thread lung (see Strongylus filaria) ...--. cece eee ee cee nne nee 201
Worm-cake, Spinola’s.....-. 2.22.2 2.0 seen ne ence cone cone cone eecee eeeeee--- 134, 157

Wolves, tape-worms in...... 222+. 222 eens cee eee oe eece rats wers cence sigeea 14
ee ar

BERR ree csi See ae ee =e =— Sees g Beers
EE DET Fre trai hS Tote : : SoH CaS ee tens