®I|p i. B. HtU library Nortl) (taroUna ^tatf linitierflita SF810 A3N48 NORTH CAROLINA STAIt UNIVERSITY 1-IBRARIES S00825643 S THIS BOOK IS DUE ON THE DATE INDICATED BELOW AND IS SUB- JECT TO AN OVERDUE FINE AS POSTED AT THE CIRCULATION DESK. WOV - 2 I98t iDtC 7 1995 A TREATISE ON THE Parasites and Parasitic Diseases OF THE ' DOMESTICATED ANIMALS. L. G. NEUMANN, ['ROFESSOR AT THE NATIONAL VETERINARY SCUOOL OF TOULOUSE. TBANSLATED AND EDITED GEORGE FLEMING, C.B., LL.D., F.R.C.V.S., LATE PRINCIPAL VETERINARY SURtiEON OP THE BRITISH ARMY ; FOREKiK CORRESPONDING MEMBER OF THE SOCIETE KOYALE DE MEDECINE, AND OF THE SOCIETE ROYALE DE MEDECINE PUBLIQUE OF BELGIUM; FOREIGN ASSOCIATE OF THE SOCIETE NATIONALS ET CENTRALE DE MEDECINE VETERINAIRE OF FRANCE; HONORARY LIFE MEMBER OF THE ROYAL ACiRICULTURAL SOCIETY OK ENGLAND; FOREIGN MEMBER OF THE SOCIETE KATIONALE D"AGRICULT0RE OK FRANCE ; CORRESPONDING MEMBER OF THE REALE SOCIETE NAZIONALE DI MEDICINA VETERINARIA, AND ACCADEMIA VETERINAKIA, OF ITALY, ETC. VITH 3tJ5 ILLUSTBATIOXS. LONDON : BAILLIERE, TINDALL AND COX 20 & 21, KING WILLIA^I STREET. STRAND. NEW YOKE: WILLIAM R. JENKINS. 1«92. I All rights reserved.] i^ pcMcate6 TO PEINCIPAL AND PEOFESSOR JAMES McCALL, F.RC.V.S. GLASGOW VETERINARY COLLEGE, AS A TOKEN OF SINCEKE ESTEEM, AND IN KECOGNITION OF GENIAL AND CONSTANT FKIENDSHIP DURING MANY YEARS. ',- r TRANSLATOR AND EDITOR'S PREFACE. As long ago as 1876, I made an attempt to supply a want which had long been experienced in English-speaking countries, by undertaking a work on the parasites and parasitic diseases of the domesticated animals. The need for such a work had frequently been seriously brought before me, as there was no complete treatise in our language to which the student of human or veterinary medicine, the sanitarian, agriculturist, or breeder or rearer of animals, could refer for full information with regard to the external and internal parasites — vegetable and animal — which attack the various species of creatures man has domesticated. But soon after its commencement I was reluctantly compelled, fr-om pressure of other duties and lack of opportunity, to relinquish the task until I could find more leisure. Subsequently there appeared in Ger- many Ziirn's useful work, Die Schmarotzer, in two parts, and in France Megnin's equally valuable book, Lcs Parasites et les Maladies Para- sitaires ; but in 1888 Neumann's treatise was issued, and as this was certainly the most complete and comprehensive of any which had j-et appeared, and the arrangement was somewhat on the plan I had adopted, while the facts and authorities brought together in it were more numerous than I could have obtained, I resolved to venture on its translation, instead of proceeding with my own independent effort. The value of such a work as this of Professor Neumann is amply testified to by the fact, that the first edition was exhausted in less than three years, while the author received the Vernois Prize from the Academic de Medicine in 1889, and the gold medal of the Societe Nationale d'Agriculture de France ; the War Minister of France has also authorized its issue to all the mounted corps and the military schools and establishments. No better evidence of its great merits could be adduced, nor can stronger proof be afforded of the recogni- tion and encouragement such labours meet with in France. Professor Neumann, with the greatest courtesy and generosity, not only gave me permission to translate his admirable work, but furnished me with revise Vm TRANSLATOK AND EDITOR S PREFACE. sheets of the second edition as they passed through the press, thus enabhng me to produce this Enghsh edition ahnost simultaneously with the new French one ; he also provided me with corrections and additions which could not appear in the body of his book. For all this goodness and attention, I beg to tender my estimable friend warmest thanks ; and I feel certain, that those who have occasion to refer to this English edition, will also gratefully recognise the benefits he has conferred upon them. There is no work in Enghsh to be at all compared with this, so far as veterinary medicine is concerned; and even in human medicine — English or foreign — there is none so comprehensive and complete. In his preface to the first edition, Neumann gives expression to the feeling which impelled me, in 1876, to make my abortive attempt ; and I may be allowed to quote as much of what he says as will indicate this, and also give some idea of the scope of his treatise. He writes : ' Those who have studied the subjects so numerous and varied, the substance of which is given in this book, will have had reason to be astonished at the multiplicity of the works in which they are treated, and the almost innumerable documents of which they are constituted. They will also have had cause to regret more than once that, in our country at least, no one has ventured to give a didactic tableau of the injury caused by parasites to the health of the domesti- cated animals. Having, as much as anyone, had to regret the existence of this void, we determined to fill it. Truly, this attempt is not alto- gether without precedent ; but none of the French or foreign works to which we have referred — excellent though some of them are — could be accepted as a model ; as some were limited to the " entozoa," others to the parasites of the skin, certain of them prematurely included microbic diseases in their list, or confined themselves to the parasites only — neglecting too much the host and the mischief they caused ; while the majority, if not all of them, adapted their plan to the taxinomic requirements of zoology and botany. ' As we had in view more particularly the damage done to health — the parasitic diseases — we deemed it useful to establish the order to be followed according to the nature of the organs invaded ; and this has been the predominant idea throughout the work — the rare deviations therefrom which had to be made being of no importance, as they will cause no trouble or hindrance to the attentive reader in determining the character of the parasites he may meet with. ' In dealing with the parasitic diseases of our domesticated animals, no notice has been taken of those very small and subtle parasites usually TBANSLiATOR AND EDITOR S PREFACE. IX designated " microbes," and which belong to the vast class of Schizomy- cetes ; for, notwithstanding the incontestable interest that invests them, as a whole, in the parasitism of animals, it appeared advantageous to omit the virulent diseases. One decisive reason, among others, justi- fied this omission ; for if among these maladies there are some the parasitic origin of which is established, there are many others, unfor- tunately, for which the same cannot be said, though they are better known, and cannot be separated from them with regard to symptoms, course, lesions, conditions of contagion, sanitary police, prophylactic measures, etc. The diseases which we here treat of are nearly all due to relatively lai'ge parasites, which might be designated macro-parasites. ' The domestic animals dealt with in this book — mammals and birds — are almost exclusively species belonging to our country, as the obser- vations regarding parasitism more especially belong to them ; the species special to Asia, Africa and America have, in this connection, an interest too secondary to warrant us in further extending our already very ex- tensive work. Therefore it is that they have only received rare and brief notice. ' Although pathology has been more especially kept in view, we have not confined ourselves to an enumeration of the troubles engendered in the economy by the organisms that invade it. In order to facilitate diagnosis, we have added to the study of the parasites — properly so called — that of the commensals which are so frequently met with ; and we have been compelled to include all the living foi-nis observed on the surface or in the texture of organs, whether they be common or rare, frequent or exceptional. ' As it is not always easy, in presence of an intrusive species, to allot it to parasitism or commensalism, and as numbers are, in this matter* a powerful element in distinguishing it, the determination of a parasite is singularly aided by comparing it with species having the same habitat. The mention which accompanies each of these gives the measure of its importance. ' In order to render a nusographical account of the parasitic disorders intelligible, it is absolutely necessary that zoological, and sometimes botanical, information be had recourse to. Generally speaking, this has been reduced to the strictest minimum, as the reader can find in other treatises or special works any further information he may require.* After alluding to the great assistance he had received from Professor Railliet, of the Alfort Veterinary School, whose valuable work, Lcs Eldmcnts de Zoologie MMicalc ct Agricolc, receives well-deserved praise, and also to Professor Peuch of the same school, our confrere adds : b X TKANSLATOR AND KDITOR S PKEFACE. ' But the reader also owes much to the multitude of scientists and practitioners whose observations have constituted the science with which we are now occupied. In endeavouriog to do justice to each, we have been desirous of furnishing the means whereby to complete the information contained in this w^ork ; and if we have multiphed the bibliographical references, the mode adopted wall, we believe, avert the inconveniences they might otherwise liave for the I'eader. And fre- quently this bibliography has been reduced to a small number of autho- rities, when these have already given a very extensive and complete list ; while it has also often been suppressed when there was reference made to such masters of the subject asDujardin, Diesing, Leuckart, Davaine, Ziirn, etc., whose works had already been oftentimes quoted from.' I have only to express the hope and desire that the subject of para- sitism, which has been so closely and advantageously studied by mem- bers of the veterinary profession — more especially in France, Germany, and Italy — will now receive greater attention from those in English- speaking countries generally — countries which cover such a large surface of the globe, and therefore offer such excellent opportunities for extending our knowledge in this important section of biology and sanitary science. I have ventured to supplement some of the author's statements, and to make some small additions in several portions of the work ; these are placed in brackets. The metric system of measurement has been re- tained, as it is the most convenient, and is now generally adopted in scientific treatises. The introduction of the micromillimetre (.a) is a great advantage in dealing with very minute objects. The title of the work I have also taken the liberty of slightly altering, in order the better to indicate its scope; as it treats not only of parasitic diseases and their treatmen'ii, but lucidly, if briefly, of the parasites themselves — an advan- tage which will be appreciated by those who wish to gain some know- ledge of them, and learn to identify them. GEOEGE FLEMING. St. John's, London, March, 1892. LIST OF ILLUSTRATIONS. lO. PAOR 1. Simidium re.pla7in. {Afler Woodward) ... ... ... ... 25 2. Autumn Breeze-Ply. [Delafond) ... ... ... ... ... 29 3. Autumnal Breeze-Fly. (Raillict) ... ... ... ... ... 30 4. Small Rain Breeze-Fly. (Railliet) ... ... ... ... ... 31 5. Small Blii.ding Breeze-Fly. (RaiUitt) ... ... ... ... 31 6. Head of the Stinging Stomoxys. (Dda/uiid) ... ... ... ... 33 7. Stinging Stomoxys. {Raillitf) ... ... ... ... ... 33 8. Tse-tsc. (RaUliet) ... ... ... ... ... ... ... 35 9. Hippoboscus of the Horse. (Railliet) ... ... ... ... 37 10. Hfc ad of the Blue or Flesh Fly. (Delafoiid) ... ... ... ... 40 11. Blue FleshFly. (Railliet) ... ... ... ... ... ... 41 12. Sarcophaya via 44. Goniocotes hologaste/- of the Vowl ... ... ... ... ... 75 4.5. O'oniocotes gigas of the Fowl ... ... ... ... ■■• ■■■ 7.'> 46. Llpeurtis rariabilis of the Fowl ... ... • ... 76 4 7 . Menopon paUidnm of the Fowl ... ... ... ... ... 75 48. Docophortis iderodes of the Dnck ... ... ... ... ... 80 49. Ornithohius Ijiicephalns of the Swa,n ... ... ... .. ... 82 oO. Pupa of the Melophagus of the Sheep . . ... ... ... ... 83 .")1. Magnified Pupa of the Sheep Melophagus ... ... ... ... 83 52. Bug of the Fowl. (Railliet) ... ... ... ... ... ■■ 91 53. Unntram of tlie Ixodes ricirins. (Delafond) ... ... ... ... 96 54. Transverse Section of the Egyptian I.xode ... ... ... ... 96 55. The Ixodes ricinus of the Dog. {Railliet) ... ... ... ... 98 56. 'I rombidium holosericeum. (Railliet) ... ... .. ... ... 107 57. Harvest Bug or Larva of the Trombidium holosericenm (Raikiet) ... 108 58. Cheyletm paras it Ivoraj- ... ... ... ... ... ... 110 59. Ti/roglyphvs /ongior ... ... ... ... ■■■ ... Ill (iO. Listrophorus gihbvs, male, of the Hsihbit ... ... ... ... Ill 61. Z/i.s//'o/jAo?*?/.s f/i6/I*?'.s, female, of the Rabbit ... ... ... ... Ill 62. Rostrum and leg of the first pair of the Sarcoptes .•icabid, var. equi. (Railliet) ... ... ... ... ... ... ... 116 6Z. Psoroptes cominvvis, vixr. e(pii. (Delajond) ... ... ... ... 117 64. Si/mbiotes anricularnm. (Railliet) ... ... ... ... ... 120 65. Sarcoptes scabiei, \a,v . equi ... ... ... ... ... ... 122 66. Sarcoptes scabiei, var. equi ... ... ... ... ... ... 122 67. Sarcoptes scabiei, \&r. tqui : hexapodal larva ... ... ... ... 123 68. .9arf07)fes scaftiei, var. e^jr* ; octopod nympha ... ... ... ... 123 69. Sarcoptes scabiei, y&r. equi ... ... ... ... ... ... 123 70. Sarcoptes minor, var. cali ... ... ... ... ... ... 124 7 1 . Sarcoptes minor, var. cati ... ... ... ... ... ... 1 24 72. Sarcoptes minor, \a,T. cati ... ... ... ... ... ... 125 73. Psoroptfls communis, va,T. equi ... ... ... ... ... 125 74. P.>^oroptescommuni.i, var, equi ... ... ... ... ... 126 75. Psoroptes communis, \AT. equi ... ... ... ... ... 127 76. P.-ioroptes communis, v&T. equi ... .. ... ... ... 127 77. Symbiotes communis, v&T. equi ... ... ... ... ... 128 78. Symbiotes communis, \ax. equi ... ... ... ... ... 128 79. Symbiotes communis, y AT. equi ... ... ... ... .129 80. Symbiotes auricularum of the Dog. (Railliet)... ... ... ... 129 81. Symbiotes anriculai-H77i of the Dog. (Raillii-t) ... ... ... ... 130 82. Sarcopt of Man ... '... ... ... ... ... ... 137 83. Egg of the !ei, in various stages of development ... ... 138 84. Anterior e.xtreniity of the i)emocZex/o//jc?t/orK/H of the Dog ... ... 213 85. Evolution of the /->e»«0(/ca:/o//tc((/onim of the Dog. (Ruillitt) ... ... 214 86. Z)emo. Merjnhiia asfernalis oi the Figeon ... ... ... ... ... 237 96. Falciger rosti'atus oi the Figeon. (RaUAitt) ... ... ... ... 239 97. Epicler77wptes bilobaf ii.'i o{ the Fowl ... ... ... ... ... 242 98. Epidermopte-^ bilobatus o( the Fowl ... ... ... ... ... 242 99. Cytodites 7mdH.'< of the Fowl. (liailHet) ... ... ... ... 243 100. Cytoditen 7mdm of the Fowl. (Railliet) ... ... ... ... 244 101. Symplectoptes cysticola of the Fowl. {Railliet) ... ... ... ... 245 102. Symplectopte'i cydi cola of the Fowl. {Railliet) ... ... ... 245 103. Sarcoptes mntawi of the Fowl ... ... ... ... ... 247 104. Sarcopte-'i mutaurs of the Fowl. (Railliet) ... ... ... ... 247 105. The foot of a Fowl affected with Scabies ... ... ... ... 248 106. Sarcoptes lawis, var. i/alUno'.. (Railliet) ... ... ... ... 251 107. Sarcoptes loivis, y2i,x. (jallina'. (Railliet) ... ... ... ... 252 108. Sarcopte.'i lan'is, var. (/allinw : la-rva,. (Railliet) ... ... ... 252 109. Filaria of hiemorrhagic tumours. (Condamine) ... ... ... ... 255 110. Granular Dermitis in the Horse. (Railliet) ... ... ... ... 258 111. Diagram of vegetation of Dermatophytes. (Ralzer) .. ... ... 272 112. Trichophyton tonsurans of the Horse ... ... ... ... ... 282 113. Horse's tail invaded by the 7'rk-Ao;j'»//o/t /o/(.s7(ra«.s ... ... ... 283 114. Head and neck of a Fowl affected with generalized Favus ... ... 303 115. ^cAorjo/t 5cAo«/e«H/(' of the Favus of Poultry ... ... ... ... 304 116. Diagram of the organization of a Trematode. [Van Benedcii) ... ... 319 117. Anatomy of the Ascaride of the Pig. (Delafoitd) ... ... ... 321 118. Digestive tube of a female of the .S'c/e>-os?o7na P7(//>i««i. (Dehifoinl) ... 322 119. Sexual apparatus of the female Megalocephalous Ascaride. (l)elafond) ... 322 120. Caudal extremity of the male of the Ascaride of the Pig. (Delii/oitd) ... 324 121. Spiculse of Megalocephalous Ascaride. (Dckifond) ... ... ... 324 122. Oral sucker and denticules of the Leech. (Carlef) ... ... ... 328 123. (xenital apparatus of the Leech. (Oarlrl) ... ... ... ... 328 124. ir/o^ia/«ca^a, (Railliet) ... ... ... 395 167. Titnia plicata. (Railliet) ... ... ... ... ... ... 395 168. Ga.strodi'icus Son.-a«sa ... ... ... 413 187. Cephalic extremity of the ToEHJa a^6a ... ... ... ... 414 188. Anterior extremity of the Ascaride of the Calf ... ... ... ... 415 189. Caudal extremity of the male i'/rowf/y^M.s i-e?t-mta. {Railliet) ... ... ... ... 439 212. Hooks of the 7'ceKJa .verra to. (Railliet) ... .. ... ... 439 213. Ttenia serrata ... ... ... ... •• •• ■•• ^-40 214. Mature segment or joint of the ytr-ma serrato. (Railliet) ... ... 440 215. Ova, oi Tctnia serrata. (Railliet) ... ... ... ... ... 440 216. Tfenia marginata ... ... . . ... ... •• •■• 441 217. Hooks oi the Tienia marginata ... ... ... ... ... 441 218. Toinia C(£nuruH ... ... ... ... ... •■■ ■•• 44;> 219. Iloo]is o{ the Ti.stort((i ec■At««^(^//l of the Duck. (Ercolani) ... 459 237. Ascaris mystax ot the Ca.t. (Railliet)... ... ... ... ... 460 238. Uncinaria or Dochmius trigonocephalus ... ... ... ■■ 162 239. Cephalic extremity of the Z>oc/»«Aate.s. (Railliet) ... ... 462 240. Caudal pouch of the DocA7ntK.s- -0Jir/i!/;«.s .«' ve-/a rejvv'/ia Caudal extremity of the female Filaria cerrina Mesentery of Rabbit with CyslicercuH pisiformis. (RaiUiet) Section of completely developed Gy^ticercux pixiformis. {Moiiiei) Phrorercoide.i. (Leuckart) Liuf/uatu/a dentindattun. (RaiUiet) ... Head of Dog, hhowmg Linguatula tanioides, (Colin) Vfing of (Extrux ovis. (RaiUiet) (iVrjw of the Sheep Ova of the Sheep CEstrus Opened p\ipa of the Sheep rE.strus LIST OF ILLUSTKATIONS. XvU KIU. I'AliK 304. Larvie of (Kstrus in f I Diital sinuses of Sheep. (Joly) ... ... ... 571 305. Stroiigylu.s Jilaria ... ... ... ... ... ... ... 58I 306. StrongyluH Jilaria. [Ddafond) ... ... ... ... ... 531 307. Strongylus rvfesctns. (Raillkt) ... ... ... ... ... 533 308. Strongijlus ru/e.icens. {Railliet) ... ... ... ... ... 533 309. Ova and embryos of .S'0-o».7////(x >•(//( Are«<. (RuiUkt) ... ... ... 585 310. Strongi/lu-'f micruriii. (Raillief) ... ... ... ... ... 593 311. Caudal extremity of male .SVro?(23. Caudal extremity of male /7/a>*ta m??i«7/-s. {Raillief) ... ... ... 640 324. Kmhryofi of Filaria inmiit is. {Railliet) ... ... ... ... 640 325. Strougylus rasoriuii. {Railliet) ... ... ... ... ... 645 326. Cwnunis serialis. (Railliet) ... ... ... ... ... ... 651 327. Distome of the muscles of the Pig. {Leuckart) ... ... ... 654 328. Spiroptera reticulata ; rnaXn. (Railliet) .. .. ... ... 656 329. Spiropttra reticulata : lemalti. (Railliet) ... ... ... .. 656 ■ViO. Spiro/jtei-a 7-eticiilata ; ipoTtion of femdile. (Railliet) ... ... ... 657 331. Ov& oi the Spiro2itera reticulata. {Railliet) ... ... ... ... 657 332. Embryos of the (S)'/>(>o^j/rtH/« f/j.7a«(a/((a ,7(V/a«g. {Railliet) 70ft 707 728 746 749 751 763 76.S CONTENTS. PACK Translator AND Editor's Preface ... ... ... ... ... vii List OF Illustrations ... ... ... ... ... ... ... xi Introduction.— The Parasitic Diseases in General ... ... ... ... 1 Vegetable Parasites ... ... ... ... ... ... ... 2 Animal Parasites ... ... ... ... ... ... ... 3 Habitat of the Parasites ... ... .. ... ... ... 6 Degrees and Mode of Parasitism ... ... ... ... ... 6 Etiology of Parasitic Di.seases ... ... ... ... ... ... 9 ~ Symptoms and Lesions ... ... ... .. ... ... 13 Diagnosis ... ... ... ... ... ..■ ... 16 Nomenclature of Parasitic Diseases ... ... ... ... ••• 17 Prognosis ... ... ... ... ... ... ... •■• 18 Prophylaxis ... ... ... ... ... ... .•• 18 Treatment ... ... ... ... ... ... ... .■• 20 BOOK I. PARASITES OF THE SKIN. Oenkral Considerations ... ... ... ... ... ... 21 CHAPTER I.— Dipterous Parasites in the Perfect Insect State ... ... 24 CHAPTER II.— Dipterous Parasites of the Skin in the Larval State ... ... 40 CHAPTER III.— The Fleas 58 CHAPTER IV.— Phthiriases ... ... ... ... ... ... 65 CHAPTER v.— Acariases ... ... ... ... ... ... 92 A.— AC A JilASES OF THE DOMESTICATED ANIMALS 95 Article I. — Non-psoric Acariases ... ... ... ... ... 95 Article II. — Psoric Acariases ... ... ... ... ... 112 1. Sarcoptiniiic Scabies ... ... ... ... .. ... 112 A. Scabies of the Equidse ... ... ... ... ... 136 1. Sarcoptic Scabi&s ... ... ... ... ... 136 2 Psoroptic Scabies ... ... ... ... ... 151 3. S3Tnbiotic Scabies ... ... ... ... ... 155 B. Scabies of Bovine Animals ... ... ... ... 157 1. Sarcoptic Scabies ... ... ... ... ... 158 2. Psoroptic Scabies ... .. ... ... ... 158 3. Symbiotic Scabies ... ... ... ... ... 162 C Scabies of the Sheep ... ... ... ... ... 163 1. Sarcoptic Scabies ... ... ... ... ... 164 2. Psoroptic Scabies ... ... ... ... ... 167 3. Symbiotic Scabies ... ... ... ... ... 191 CONTKNTS. BOOK I. (coudiitiHl). D. Scabies of the Goat 1 . Sarcoptic Scabies 2. Symbiotic Scabies K. Scabies of the Pig F. Sarcoptic Scabies of the Rabbit ... Vt. Scabies of the Dromedary and Camel H. Sarcoptic Scabies of the Dog I. Sarcoptic Scabies of the Cat J. Sarcoptic Scabies of the Ferret 2. Dtmodecic Scabiex A. Demodecic Scabies of the Dog B. Demodecic Scabies of the Pig C. Demodecic Scabies of the Coat D. Demodecic Scabies of the Ox B. —A CA HIASES OF DOMES TIC A TED BIRDS AKTICLK I. — XON-PSORIC ACARIASE-S Article II. — Psoric Aoariasks 1. Scahief of the Leff 2. Scabies of the Body, Depluming ScabieK CHAPTER VI.— Cutaneous Helminthiases Article I. — Pahamtic ])ermatorkha(:e Article II. — Summer Sores of Horses Article III.— Draconti.asis (Filaria oi- Medina) Article IV.— Ixdigenols Cutaneous Filariasis of the Dog Article v.— Verminous Foot-bot OF Sheep ... CHAPTER VII.— Cutaneous Psorospermosis CHAPTER VIII. Dermatomycoses Article I. — Tinea Tonsurans Article II. — Favus Article III. — Onichomycosis of the Equid.e ... BOOK II. PARASITES OF THE DIGESTIVE APPARATUS. GeNER.\L CONSlDER.\TIONS CHAPTER I.— Parasites of the Mouth and Pharynx .-VRTICLK I. — H.EMOl'IS Article II.— Thrush Article III.— (iuTTUROMYCosis OF Et^uiD.E Article IV.— Diphtheria OF Fowls ... CHAPTER II.— Parasites of the (Esophagus and Stomach ... Article I.— Parasites of the (Esophagus and Stomach of Equid.e .Vrticle II.— Parasites of the CEsoph.vgcs and Stom.\ch of Ruminants Article III.— Parasites OF the Stomach OF the Pig ... Article IV.— Parasites of the (-Esophagus and Stomach of the Dog Article v.— Parasites OF the Stom.ach OF the Cat Article VI. — Parasites of the Stomach of the Rabbit Abtiolk VII.— Parasites of the (Esophagus and Stomach of Birds BOOK II. [contitiued). PAOR CHAPTER III.— Parasites of the Intestines ... ... ... ... 378 A.— DOMESTICATED MAMMALIA 392 Article I.— P.\UASiTEs OK THE Intestines OF THE Eql'id.e ... ... 392 Article II.— Par.\site8 of the Intestines of the Ox ... ... ... 411 Article III.— Parasites OF THE Intestines OF THE Sheep ... ... 418 Article IV.— Parasites OF THE Intestinfs of the Goat ... ... 429 Article v.— Parasites OF the Intestines OF THE Pic ... ... ... 429 Article VI. —Parasites of the Intestines OF THE Dof; ... 436 Article VII.— Parasites OF THE Intestines OF THE C.\T ... ... 4t37 Article VIII.— Par.\sites of the Inte.stines of the Rabbit ... ... 472 Article IX.— Parasites OF THE Intestines OF the (iuiNEA-i'K; ... ... 475 Article X.— Parasites of the Stoii.\ch and Inte.stinf.s of the Elefhant 475 -&.— DOMESTICATED BIRD-! 476 Article I.— P.\RAf>iTEs of THE Intestines OF Poultry ... ... ... 476 Article II.— Parasites of the Intestines of the Tlrkey, (iriNKA-FOWL, Peacock, and Pheasant ... ... .. ... 484 Article III.— Par.\sites OF the Intestines OF the Pigeon ... ... 485 Article IV.— Parasites OF THE Intestines OF THE Duck ... ... 487 Article v.— Par.\sites OF the Intestines OF the GoosK .. ... 491 Article VI.— Parasites OF THE Intestines OF THE Swan ... ... 494 CHAPTER IV.— Parasites of the Liver ... ... ... ... ... 495 Article I.— Cocciniosis OF THE Liver ... ... •• •'01 Article II.— Echinococcosis OF THE Liver ... ••• ■• ;*06 Article III. — DisTOMATOsis OF THE Liver 1. Dlstomatosls of Herbh-ora 2. Dixtomato.-iis of Caniiiwa CHAPTER v.— Parasites of the Pancreas and Spleen ... ... 546 BOOK III. PARASITES OF THE SEROUS MEMBRANES. 516 517 544 547 550 551 Equidae Ruminants Pig Rabbit Dog and Cat . . . BOOK IV. PARASITES OF THE RESPIRATORY APPARATUS. General Considerations A.-DOMESTICA TED MA MM A LI A •'^58 CHAPTER L— Parasites of the Nasal Cavities and Larynx .. ... 558 Article I.— Linguatul-e ... ... ••• ••• •• ■ ^^f Article II.— Larv-e OF the CEstrus ... ... ... •• ... 567 CHAPTER II.— Parasites of the Trachea, Bronchi and Lungs ... ... 57o Article I.— Pulmonary Echinococcosis ... ■• ' ^.l^ Article IL— Pulmonary DisTOM.^TOsis ... ... ••• ... .^79 Article III. —Bronchial and Pulmonary Strongyloses ... ... 580 1. Verminous Broncho-pneumonia of the Shcfip and Goat ... ■■■ o83 2. Verminous Bronchitis of Boviue.s ... ... ••■ •• ■ -'^l BOOK IV. icontinwd). PAdK 3. Verminoux Bro)ichitiii of the Camel ... ... ... ... 594 4. Vcrminoit-'i Ih-oiir/ii(it of Equiiicfi ... ... ... ... ... 595 5. Verminou>t lironchith of the Puj ... ... ... ... ... 596 6. Verminous Bronchitis of Ike Domedicaled Rabbit ... ... ... 598 Article IV.— Hklminthiasks of the Trachea, Bronchi anh Lungs of the Dor. ... ... ... ... ... ... 598 Article V. — Hf.lminthiases ok the Trachea, Bronchi anh Lungs ok the Cat... ... ... ... ... ... ... tiO'2 ■&.— DOMESTICATED BIRDS 605 CHAPTER I.— Verminous Tracheo-Bronchitis (Syngamosis).. ... ... 606 CHAPTER IL— Mycosis of the Air-Passages ... ... ... ... 612 BOOK V. PARASITES OF THE CIRCULATORY APPARATUS. General Considerations CHAPTER I.— Haematozoa of the Horse .. Article I.— Infusoria Article II.—Xem.\todk.s CHAPTER II.— Hsematozoa of Ruminants CHAPTER III.- Haematozoa of Rodents CHAPTER IV.— Haematozoa of the Dog . . Article I. — H.icmatozoa of Lewis Article II.— H.kmatic Filariosis Article III.— .Strongylosis ok Blood-ve.ss Article IV.— Spiroptera Sanguinolknta CHAPTER v.— Haematozoa of Birds 618 619 619 6-2-2 6n.^ 6:56 636 6:i9 64 » 640 648 BOOK VI. PARASITES OF THE MUSCLES, CONNECTIVE TISSUE AND BONES General Considerations Ccenurus Cerebralis Ccenunis Seriali.s Echinococci ... Distoma Hepaticum Uistoma of the Muscloa of the Pig Nematodes Spiroptera Reticulata ... CHAPTER I. — Psorospermosis of the Muscles and Connective Tissue Article I.— Muscular Psorospermosis Article II.— Connective-Tissue Psorospermosis CHAPTER IL -Measles Article I. — Measles of the Pig Article 1 1. — Measles of the Dog Article III.— Measles OF THE Ox Article IV. — A'arious Meastes CHAPTER III.— Trichinosis CHAPTER IV.— Parasites of the Bones (Echinococci) 650 650 651 652 654 fi54 655 6.56 667 668 688 697 699 724 CONTENTS. xxiii BOOK VII. PABASITES OF THE NEBVE CENTRES AND ORGANS OF SENSE. I'AOB CHAPTER I.— Parasites of the Nerve Centres ... ... ... ... 726 Article L— Wandering Helminths ... .. 726 Article II.— Hydatido cephalus or *Gid' .. 727 .\rticle III.— Larv.e of the CEstrid.k .. 741 CHAPTER II.— Parasites of the Organs of Sense . .. 743 Article I.— Parasitk-s OF THE Ear .. 743 1. Psoroptl'. Otarariaxe^ .. 745 A.— Psoroptic Otacariasis of the Rabbit .. 745 B.— Psoroptic Otacariasis of the Goat . . .. 748 •-'. Symbiotic Otacariasis ... .. 748 A.— Symbiotic Otacariasis of the Dog .. .. 748 B. —Symbiotic Otacariasis of the Cat . . .. 753 C. — Symbiotic Otacariasis of the Ferret .. 754 .\kti(le II.— P.\R.\siTE.s OF THE Eye ... .. 754 1. Ocular Cystlcf.rcosis and Echinococcosis .. 756 2. Intra-ocular Filariosia ... .. 756 :;. Erf ra- ocular Filar iosis ... .. 759 BOOK VIII. PARASITES OF THE GENITO-URINARY ORGANS. CHAPTER I.— Parasites of the Urinary Organs ... ... ... .761 A.-Fungi 7t!l B.— Coccidia ... .. 761 C— Cestodes ... .. 762 D. — Trematodes .. 763 E.— Nematodes .. 764 F.— Acari .. 770 G.— Larvie of the (Estridae .. 770 CHAPTER 11.— Parasites of the Genital Organs .. 771 Mammalia . 771 Birds .. 772 Alphabetical Index of the Authorities (jcoted .. .. 774 Alphabetical Index of Contents . . 782 Errata KT Addenda .. 798 V ^ A TREATISE ON THE NON-MICROBIC PARASITIC DISEASES OF THE DOMESTICATED ANIMALS. INTRODUCTION TO THE PARASITIC DISEASES IN GENERAL. Among the diseases which are engendered in the external media surrounding animals, a large number are due to inferior organisms contained in these media — organisms in various stages of develop- ment, from the egg to the perfect individual The recent and un- interrupted progress of science daily increases the domain of this section of pathology, and incessantly tends to include disorders which, until lately, were ascribed to purely physical causes. Hence has arisen a kind of special science. Parasitology , which has a distinct object and methods, and possesses a particularly suggestive interest. In the immense laboratory of living matter representing the organic world, the conditions of nutrition are so framed for animals, and also for non-chlorophyllous plants, that their aliment is exclusively com- posed of organic substances. The majority of these organisms subsist on lifeless matter ; but there are many which prefer deriving their nourishment from living beings, and so obtain it during a part, or even the whole period of then- existence. When the relations between size and strength are such that the consumer is inferior to its victim, the former becomes the parasite of the latter. Parasitism is, therefore, only a particular instance of Symbiosis (De Bary); and the various forms of life in common of different organisms are so named, there being distinguished mutualism, com- mensalism, and parasitism (P. J. Van Beneden). In mutualism, or mutualistic symbiosis, the two beings in contact form a real association or union. In conwiensalism one of the two alone profits by this union, in which it finds a refuge, and also, without ff Z TREATISE ON PARASITIC DISEASES. injuring its co-symbiot, more favourable, if only contingent, conditions for existence. In parasitism, or antagonistic symbiosis, only one of the organisms, again, gains by the union, \Yhich affords it an assured shelter and subsistence — sometimes only the latter — most frequently at the expense of its co-symbiot, which in this case becomes its host (or hearer). It is in this sense that we adopt the word ' parasite,' and so give it an extension which will be at least justified by the aim of this work. The Parasites {■7rapd(riTo<;, eating beside or with another, from Trapd, beside, and o-iro?, food) which live on the domesticated animals (Mammals and Birds) belong to the vegetable or animal kingdoms. All the vegetable parasites {Phytoparasites) are fungi ; all the animal parasites {Zooparasites) belong to the Invertebrata. Vegetable Parasites. — The majority of the parasitic Fungi of the domesticated animals are included in the group — order or family — of Scliizomycetes, Bacteria or Bacteriaccce. They are formed of a single cell destitute of nucleus, the homogeneous protoplasm of which is generally colourless, and is enveloped in a thin membrane. Their essential mode of multiplication is by division, nearly always trans- versal, and rarely in two, or even three directions. Among them are found the most minute organisms. If, indeed, some of them (Lepto- thrix. Spirochete, Spirillum Volutans, etc.) may measure two to ten millimetres in length (200 /x), there are many that reach the limit of the highest magnifying powers of the best microscopes. All the inferior organisms which are now popularly designated Microbes, belong to the Schizomycetes. The considerable part they play in the general economy of Nature is every day rendered more evident by the progress of science, and there is a particular tendency to give them a more and more preponderating influence in the etiology of infectious and con- tagious maladies — such as Bacteridian Anthrax, Symptomatic Anthrax, Fowl cholera. Swine-plague, Tuberculosis, Typhoid Fever, etc. These p)athogenic microbes, as they are called, are now considered the virulent agents proper to each of these affections ; and their multiplication by cellular division in the body of an animal, affords an explanation of all the characteristic processes noted in these diseases. Their rdle in pathology, the special nature of the disorders they occasion, their biological physiognomy, the special and delicate methods their study demand, and the different points of view from which they may be considered, separate them distinctly from the other parasites. It is for this reason that they are not comprised in this work, which is devoted only to parasites relatively gigantic for the most part, localized in one or more organs or tissues, never intimately mixed up in the fluids, and the pathogenic action of which rarely implies the intervention or knowledge pertaining to sanitary police. But it must INTBODUCTION. 3 be stated that there are between these two large groups of parasites some intermediate ones : Schizomycetes, such as the Sarcinae ; the Micrococcus of the funinculus ; the Actinomyces bovis, etc., which very closely localize themselves ; and macroparasites which, at certain phases of their development, invade the circulating fluid — as the embryos of the hasmatozoa. Notwithstanding these few exceptions, there are rather advantages than inconveniences in separating these two groups of parasites, in order to study them. Only a small number of para- sitic fungi will, consequently, be referred to in this work. These are : 1. The Dermatophytes {Tricopliyton tonsurans and Achorion Schoen- leinii), which live on the skin, and may be likened to the Mucorinee ; they will be studied when dealing with the parasitic dermatoses. 2. The Saccharomycetes, such as the Sacclmromyccs {Oiclium) albicans, which infest the upper digestive passages and produce ' thrush '; and the Saccharomyces guttulatus, found in the stomach and intestines of various herbivorous animals. 3. The Haplococcus rcticulaius, a muscle parasite of the Pig, and which resembles the Vampyrellse. 4. Lastly, several kinds of Aspergillus, ' moulds ' belonging to the family of Perisporiacse, which may develop in the respiratory ap- paratus of Birds and some Mammals. These groups of fungi are distinctly separated from each other by the seat of the alterations they produce, and it is therefore preferable to refer what has to be said about them to each of the chapters devoted to the organs or tissues they invade. Animal Parasites. — Three sections only of the animal kingdom contain the parasites of the domesticated animals ; these are the Pro- tozoa, Worms, and Artliropodes. A. The Protozoa are very small, often microscopic creatures, formed of a single and more or less complex cell, and possessing neither differential organs nor tissues. Their reproduction never requires the intervention of male or female sexual elements (spermatozoids and ova), but takes place by fission, budding, and sporulation ; at most, it may sometimes be preceded by the definitive or transient fusion of two or more individuals {conjugation). They are divided into five classes : Monera, Amoeba, Ehizopoda, Sporozoa, and Infusoria ; only three of these classes {Amoeba, Sporozoa, Infusoria) contain parasites of the domesticated animals. a. The Amoeba are nucleated Protozoa, destitute of cilia and flagellum in the adult state, and only showing pseudopodes, i.e., variable pro- longations which may be withdrawn into the body, and are here ordinarily broad, obtuse, and well defined. The only parasite certainly belonging to this class is the Amoeba parasitica, discovered by E. von Lendenfeld in ulcers of the lips and feet of Sheep. 1—2 4 TREATISE ON PARASITIC DISEASES. h. The Sporozoa are parasitic Protozoa provided with a nucleus, and generally limited to the adult age by a hairless cuticle which has no flagellum or suckers. They are reproduced by spores, resulting from segmentation of their protoplasm or sarcode. They are often designated PsorospermicB. Balbiani has arranged them in five orders : G-regarines, Coccidia {Psorospicrmia' oviformes), Sarcosporidice (Psoro- spermia' iitriculiformes), Myxosporidkc {Psorospcrinmof Fish), and Micro- sporidiw {Psorospcrmiiv of the Arthropodcs). The Psorospermiae which concern us are the Coccidia and Sarcosporidias. The first chiefly in- habit the digestive apparatus, the second are found exclusively in the muscles. c. The Infusoria are Protozoa provided with a nucleus, and, generally, a cuticle bearing cilia, flagella, or suckers. They are divided into three sub-classes according to the nature of their appendages : 1. The Flagel- lata, which never have cilia, but are always furnished with one or more flagellata, and sometimes wuth an undulating membrane ; 2. The Ciliata, covered at all ages wath vibratile cilia over the whole sur- face or only partially ; 3. The Tcntaciilifcra, which, in the adult state, have only suckers in the form of tentacula. Infusoria are more par- ticularly found in the digestive apparatus, or its dependencies, of the domesticated animals : they belong to the Flagellata or Ciliata. B. The Worms are Invertebrate, with a soft contractile body, which is symmetrically bilateral and non-articulated, or is markedly divided into a linear series of similar (homonymous) rings, is always destitute of articulated limbs, and is provided with a system of excretory organs in pairs (aquiferous vessels) opening externally. This section contains a vast collection — the Helminths (eA/[/.u's, worm) — which do not form a very natural zoological class ; but from our point of view it is useful to bring them into one group, because of the analogies in their habitat, and their customs and actions. These are the Worms which are generally parasitic; they are cylindrical or flattened, are always destitute of a ventral chain of nerve-ganglia, and have no rotatory apparatus for locomotion. All those we treat of belong to this group, with the exception of a small number which pertain to the Annehdce. The Annelidce have the body cylindrical or flattened, are distinctly ringed, and have always a ventral chain of nerve-ganglia, an a:sophageal collar, a cerebroid ganglion, and a blood-vascular system. The Ilievwpis — parasites of the mouth and pharynx — are the only Annelides that enter into our study. The Ilehninths demand a more detailed description. Simple in their organization, they are — especially as parasites — unprovided with sen- sory organs, and their feeble respiration is always carried on through the integuments. Designated in many works as Eniozoa, intestinal Worms, etc., although they may be found in ^various organs, they are INTRODUCTION. divided into two classes : the Plathclminths, with bodies generally flat ; and Nemathelniinths, whose bodies are nearly cylindrical. The Plathelminths or Platodes [TrXarvs, wide, flat) comprise three orders : Cestodes, Trematodcs, and Turbellaries. The first two only are limited to a parasitic existence. Nearly all the species are herma- phrodites. a. The Cestodes or Ccstoldes (K-eo-ros, band, and dSos, form) are Plathelminths whose bodies are nude in the adult condition, ribbon- shaped, nearly always segmented, and provided at one extremity with organs of fixation — suckers or hooks ; they have no digestive apparatus. In the adult state, they live in the intestines of the higher animals ; but before that period they undergo a certain number of metamor- phoses and migrations, which are often effected in the most diverse organs of different hosts. b. The Trematodcs (T/)>//xaTw6r/s, perforated) are Plathelminths, the bodies of which are nude, soft, and non-segmented, generally fohaceous, and furnished with one or more suckers ; they have a digestive canal having a single opening and no anus. Those which concern us live as parasites in the interior of the body of their host (endoparasites), and belong to the sub-order of Distomata, which is characterized by the presence of two suckers at most, of which the anterior is oral. The Nemathelminths (vv//xa, thread) or round Worms, in which the sexes are nearly always separate, comprise two orders : AcantJwcepliali and Nematodes. c. The Acantlwcephall have no digestive canal, and have a protractile proboscis armed with hooks. They include only the Echinorhijmhus, which, in the adult state, lives in the digestive canal of Vertebrates. d. The Nematodes or Nematoidcs have a digestive canal, generally complete, wdth two openings. They are elongated, frequently slender, and even fihform. Their number is considerable, and they are found in all the organs of the domesticated animals, with the exception of the bones and the nervous system. C. The Arthropodes are Invertebrates, symmetrically bilateral, formed of dissimilar rings (heteronymous), and always provided with articulated limbs. There are four classes : Crustacea, Arachnida, Myriapodes, and Insects. The Arachnidas and Insects alone contain species which are parasitic in the domesticated animals. a. The Arachnidce are air-breathing Arthropodes, respiration being effected by a trachea and lungs, or by the cutaneous surface ; the head is usually fixed to the thorax (cephalothorax) ; there are two pairs of masticatory appendages (gnathites), four pairs of feet, no wings, and an apodous abdomen. Of the ten orders into which they are divided, two alone include parasites of warm-blooded Vertebrates : these are theLliujuatuke and the Acari. The first live, when adults, in the air- passages, but in the larval state they infest the internal organs. The 6 TREATISE ON TAKASITIC DISEASES. parasitic Acari almost exclusively inhabit the surface or the substance of the skin. b. The Insects are air-breathing Arthropodes, with a trachea, having their bodies divided into three distinct parts (head, thorax, and abdomen), the head carrying a pair of antennae, the thorax three pairs of feet, and most frequently two pairs of wings. There are seven or eight orders, only two of which— the DqAcra and Hcmii)tcra—contQ.m parasitic species, nearly all of which live— at least in the adult state —on the surface or in the substance of the skin. More extensive zoological details on the various groups of parasites (orders, families, tribes, etc.) will be given when studying the affec- tions to which they give rise. Habitat of the Parasites.— Parasites live on the surface of the skin or in organs. The first are named ectoimrasites, and the second ciuloijarasites. The ectoparasites are vegetable or animal. The first are called (lcrmatoi)hytes, and the others einzoa or cntozoa. The two last names are generally, however, more particularly applied to the apterous Insects known as FedicnlidcB, and which include Lice and Ricinida, The other animal ectoparasites are the Acari and Insects. The vegetable endoparasites comprise all the phytoparasites other than the dermatophytes. The animal endoparasites are the Sporozoa, the Infusoria, and the Worms; there are also a certain number of larviTo of Insects, and notably those of several CEstridse. The term Entozoa, which is quite suitable, is also applied almost exclusively to Helminths. Degrees and Mode of Parasitism. — Parasitism occurs in various degrees. It may he facultative or obligatory. Facultative or occasional parasitism (Leuckart) is rarely met with beyond the Fungi, and particu- larly the Schizomycetes, a large number of which may develop indiffer- ently in lifeless media, in organic matter undergoing decomposition, or in living bodies. Nearly all the parasites embraced in our study pre- sent obligatory or constant imrasitisni (Leuckart); their development necessarily admits of it, at least during a portion of their existence. From this point of view, parasitism is transitory or i)ermanent. It is transitory for the creatures which, during a portion of their lives, may be nourished external to an animal organism; and sometimes it may take place only during early age — as in the case of the O^stridae, only the larvae of which are parasites ; at other times, it is only at adult age — such are the Ankylostomes, the Ixodes, and the Chigoe (or Chigre). Permanent parasitism extends from the hatching of the egg and hberation of the embryo, to reproduction in the adult. The majority of the Entozoa undergo permanent parasitism. INTRODUCTION. 7 Parasites may also be fixed or erratic, according as they have a narrowly defined habitat and cannot pass from one host to another (Helminths, Linguatulae, larvae of the (Estridae), or enjoy a more extensive domain (Lice, Ticks, psoric Acari, Fleas, Bugs, Gnats, Leeches, etc.). For the latter — obligatory and erratic parasites — parasitic life may be essentially intermittent, that is, when they only visit their host to obtain nourishment, leaving immediately afterwards. Such are the adult Diptera (Stomoxes, Haematobia, Tabanidae, Simulidae, Gnats, etc.), which, when they are gorged with blood, forsake their enter- tainer and fly to other occupations. Parasitism is continuous for those which remain permanently on the surface of their host for genera- tions : Lice, Ticks, and psoric Acari. Bemittent parasitism is an intermediate form between intermittence and continuity, and examples are furnished by the erratic parasites which breed away from their hosts, and are not so closely attached to them — such are the Lice, Hippoboscidae, Haemopis. The mode of reproduction is, in fact, one of the principal factors that determines the conditions in which parasitism shall take place ; and in proof of this, there is the profusion with which the germs are produced — this tending to compensate for the multitudinous causes of destruction to which they are exposed. With regard to intermittent and remittent parasites, reproduction is independent of the host, copulation usually occurring far from the latter, and ovulation always. Transient parasitism often commences at ovulation and terminates at adult age (larvae of the Q3stridae). Independently of the cases mentioned above (continuous parasitism), in which generations succeed each other indefinitely in the same host, there are others in which eggs, deposited in the body of the entertainer, are soon expelled, and must remain external until they reach the maturity indispensable for their hatching. The latter may take place either in an external medium, or in a new host into which the eggs may have penetrated by various channels. The Helminths offer in this respect extremely varied types, of which we shall only notice those relating to the parasites of the domesticated animals, or to neighbouring and better known species. Sometimes complete evolution of the species only requires one host, sometimes it demands two, successive and, in general, specifically difi"erent hosts. Parasites may therefore be termed monoxenous {fj.6vo ^^]^^^^^ and watering-places, and in beds of reeds. It makes a ijgj./ loud buzzing noise, which is easily recognised again when it has once been heard. If Bruce is to be believed, the buzzing of the Tse-tse is " a mixture of dull and sharp sound, which is somewhat dis- cordant. This buzzing causes more terror and disorder among men and animals than the monsters of the countries they inhabit could produce, if they were twice as numerous." ' Many travellers — among others, Livingstone and Oswald — have stated that this Fly is one of the most redoubtable scourges of the African torrid zone ; nevertheless, the descriptions published with regard to it have, it appears to us, something of a legendary character. Like the Stomoxes, the Tse-tse attacks Man and animals. It darts on the latter, say the travellers, with the rapidity of an arrow, and prefers biting them inside the thighs or beneath the belly, and a tumour soon forms at the part attacked. ' It has been said that this insect prefers the uncovered parts of the body ; that the action of its bite on Man is no more dangerous than that of the Gnat ; that the domesticated animals, on the contrary — with the exception of the Ass, the Elephant, and the Goat — begin to waste away immediately, and soon succumb ; that Dogs resist the bites when they are fed on venison, but perish when they receive milk ; that Calves nourished on milk, on the contrary, are exempt from injury, etc. On autopsy, the heart, lungs, and liver are found more or less affected. ' The majority of these descriptions of the older travellers have been contradicted by more recent observations. Thus, a Belgian expedition has lost several Elephants ; P. Baur has witnessed several of his Asses perish as a result of the stings of this Fly, and he asserts that, instead of preferring uncovered parts, the Tsd-tsr usually gets underneath the clothing and up the sleeves of men, and below the tail of animals. Others have observed that those bitten generally succumb as a conse- quence of the gradually-increasing weakness, which may continue for several weeks, and even months. Finally, the most careful autopsies have not revealed any lesion of the spleen, liver, lungs, or brain. ' All these contradictory statements show that the action of the Tsd- tsc punctures is extremely variable, and that, consequently, they ought not to be venomous. Besides, ^Socard and myself have introduced, ' A. Laboulbene. Sur uiie Mouche Tse-ti^ de I'Afriqne auslrak. Bull. Acad, de Med., 3rd series, XIX., 1888, p. 721. 3—2 36 TREATISE ON PAKASITIC DISEASES. without any result, beneath the skin of the thigh of a Sheep, the head and proboscis of a Ts4-ts^, brought from Zanzibar a short time before by Paul Leroy. ' In reality, the Tsi-ts^ coxv merely be regarded as a carrier of virus, and its bite is only dangerous when its proboscis has been previously in- fected. "With regard to the virus that it habitually inoculates, it is difficult, in the present state of our knowledge, to say what it actually is ; but contrary to what Megnin has advanced, it is impossible to say it is that of anthrax — at least, in the majority of instances. We have already given the opinion that it might well be the virus of various maladies, and, perhaps, even of affections peculiar to Central Africa. This manner of looking at it appears the only way by which to explain the diversity of statements given by travellei-s.' Kay Lees has attributed to the Tsd-ts^, but without sufficient proof, the mortality occurring among Horses and Mules of the English army in Northern India. ^ The small family of Pupipara, or Hippoboseidse, naturally con- cludes this hst, for the Insects composing it live exclusively as para- sites, either on Mammals or on Birds. The name has been given to it by Latreille, as the family does not lay eggs, but pupae or nymphse. In reality, according to Leuckart, the eggs developed in the ovaries undergo, in a dilatation of the vagina, the evolution which leads to the formation of larvae ; the latter remain in this organ, where they are nourished on the secretions of the glandular appendages of the uterus, undergoing several moultings, and acquiring their development before expulsion. Immediately after this hatching, they are transformed into pupae. Therefore, the term ' Pupipara ' is not quite exact. (In the pupa state, the insect is in the form of an egg, nearly as large as the abdomen of the mother, this region being covered by a continuous membrane, without distinct rings, and capable of great dilatation — a structure necessary in the female, from the peculiar manner in which she brings forth her progeny. When the pupa case is expelled it quickly becomes hard, and suddenly enlarges to a greater size than the abdomen itself in which it was contained. The larger end has a sort of hood, which the insect scales off as soon as it is ready to make its escape.) These Insects have a flat wide body of a leathery consistency. The rostrum comprises only a sucker, formed of an extensive tube contained in a setiform, horny sheath, which is in its turn protected by two velvety valves. The antennae are rudimentary, and usually reduced to scarcely apparent knobs. The legs are strong, and terminate in den- tated hooks. The wings may be absent, and the insect is then a per- manent parasite, like the Lice. Only two species of Pupipara interest us. One is the Melophagus of the Sheep, and is apterous — consequently a permanent parasite, and does not enter the group now under consideration. The other is the ' Kay Lees. Olossiiia Morsilaiis, or Tue-tse Fly. The Veterinary Journal, XXVI., 1888, p. 79. DIPTEROUS PARASITES IN THE PERFECT INSECT STATE. 37 Hippoboscus of the Horse {Hippohosca equina Linn.), which lives in intimate relation with the domesticated animals, but being provided with wings, easily quits its host, and therefore belongs to the group of remittent parasites. The Hippoboscus of the Horse, Spider Fly (Keaumur), or Flat Fly, is about 8 mm. in length. The head is yellow, has a brown spot at the summit, and is salient and distinct from the thorax ; the eyes are dark. The thorax is brown, with three yellow spots, one at each anterior angle, the other median, posterior and triangular ; the scu- tellum is white, margined with brown. The abdo- men is yellowish-brown. The legs are deep yellow, with some brown bands, and the tarsal hooks are bifid. The wings are oblong, rounded, fuliginous, and have nervules only in their antero-external third. The body is covered with short stiff hairs at inter- Fig. 9. — Hippoboscus vals. According to Leuckart, the transformation ^ S^^two° dfaSrs' from the pupa into the perfect insect requires about _!Raimet. ^^^^ ^"' a month. This Insect is very common in summer, and sometimes attacks Cattle and Dogs, but it more particularly selects Horses, fixing itself on their flanks, and especially on smooth parts — as around the anus and vulva, and on the perinaeum and inner aspect of the thighs. It runs with rapidity on the body of its host, and certain animals which are par- ticularly sensitive to its presence, kick furiously at the contact of a single Hippoboscus. Habit, in the course of time, overcomes this irritability, and Horses learn to endure swarms of these insects without ■disturbance. They are very difficult to drive away, always obstinately returning, and their coriaceous integument resists a moderate degree of pressure intended to crush them. When animals are badly groomed, the Hippoboscus only leaves them at long intervals. Eondani has separated into three species the different forms which the Hippohoaca equina may present. Thus he distinguishes : H. caimia, which attacks various Mammals, but more particularly the Dog ; E. equina, which torments Horses, Cattle, Dogs, and other animals ; and H. taurina, found on the Ox.^ Preventive and Curative Measures against the Action of the Diptera. — The various Diptera, generally designated by the name of Flies, cause different degrees of injury to the health of animals. At least, they prevent them resting in their habitations, and they increase their fatigue during work by the superfluous movements and incon- venient attitudes they compel them to assume. It is, therefore, useful to endeavour to prevent their approach. What is most necessary is to keep them away from the interior of habitations, or, at any rate, to destroy them there. The first object to ' C. Rondani. HippoboticUa italka in Ja7nilias et genera dhtribiUa. Bull, della Soc. Entom. Italiana, XI., 1879, p. 3. 38 TREATISE ON PARASITIC DISEASES, be attained is keeping these in comparative darkness ; but curtains, blinds, and shutters interfere more or less with the ventilation. A pro- cedure indicated by Spence as resorted to in Italy, and which avoids this inconvenience, ' consists in providing the windows externally with a simple net, the meshes of which may be wide enough to allow several Flies to pass through at a time. If the light enters at only one side of the building, the Insects will not venture to traverse the net ; but if, on the contrary, there is a window in the opposite wall which admits the light, they will not hesitate to enter ' (Railliet). When Flies have entered the dwellings, it is somewhat inconvenient^ to endeavour to expel them by means of certain odorous substances, and it is preferable to impregnate certain parts of the bodies of the animals themselves with a solution of bitter, nauseous materials, such as those mentioned below. In some countries, while the animals are out of doors, it is customary to burn the dry leaves of the pumkin, the acrid smoke of which immediately drives out or kills the Flies. In other countries, small bundles of heather, broom, willow, or ferns, are suspended from the ceiling or walls, and in these the Flies take refuge during the night, and while they are asleep the wisps are shaken over a fire and the Insects in this way destroyed. During work or while at pasture, animals can be protected by means of covers and linen sheets. The garniture most employed with this ob- ject, is the net that is spread over thebodiesof Horses and working Oxen, and which is bordered by a fringe of twine, the continual movement of which keep away Insects. Sometimes this fringe, fastened to the reins on each side, constitutes all the caparison ; and only too frequently the protection for the Ox is reduced to merely a bit of cloth covering the face, and which defends the eyes and muffe. The abdomen is some- times protected by a kind of linen apron. The bonnet or liood which envelops the ears, neck and face, prevents the entrance of Flies to the ears. Much employed in the east of France and in Germany, this is made of net or, better, of linen. These contrivances are often re- placed by twigs and branches of trees, which, tied to the saddlery, by their continual movement drive away the Insects. Finally, the bodies of animals may be dressed with odorous, bitter, or nauseous substances. In many countries, use is frequently made of a decoction of walnut-tree leaves, or of a maceration of them in vinegar. This need only be applied to the skin once a week. Sometimes it is sufficient to merely rub the animals with the walnut-tree leaves. There have also been recommended weak decoctions of tobacco (3 oz. to the quart of water), aloes (3 drams to the quart), and assafoctida (2 oz. in 5 oz. of vinegar and 8 oz. of water). Substances should be avoided — such as empyreumatic oils— which soil the harness and the coats of the animals, and are not superior in their effects to those just men- tioned. The lotions and frictions need rarely be generally applied, but DIPTEKOUS PARASITES IN THE PERFECT INSECT STATE. S9 should rather be localized on the regions of the body which are most- sensitive, or which the Insects prefer. There are no particular indications to offer with regard to the acci- dents that may sometimes be occasioned by the dipterous parasites ; and attention has only to be directed to the local or general phenomena which present themselves. Usually cold affusions, douches, and local or general bathing, cause the disappearance of the tumefaction and pruritis that are manifested, and it is only these that appear to demand therapeutic intervention. CHAPTER II. DIPTEKOUS PARASITES OP THE SKIN IN THE LAKVAL STATE. A CERTAIN number of Diptera pass their larval phase either in wounds on the surface of the body, or in the substance of the skin itself. Sometimes this sojourn is only accidental for them, and at other times it is absolutely necessary. Parasitism is, therefore, less complete for the former than it is for the latter, which only comprise the larvae of the (Estridae, and which are, for this reason, named cuticoles. All these larvae are acephalous ; the anterior extremity is destitute of eyes and antennae, and has, at most, two horny hooks ; food is introduced into the mouth by suction. On transformation into nymphee, the skin be- comes hardened and assumes the form of a small barrel {barrelled impa), in the interior of which is the real pupa. The perfect Insect makes its escape by raising a more or less rounded valve. The term Myiasis (Hope) {iwla, fly) desig- nating every disturbance due to the larvae of Diptera, it is naturally only a question here of Cutaneojis Myiasis. This is caused by the larvae of the Muscidea or Qj^stridae — sub- order of Brachycera. ■ LARViB OF THE MusciD^. — The latter be- long to the genera Sarcophagus, Lucilia, and Ochromyia; for it is not proved that the blue fllesh-Fly {CallipJwra vomitaria Dav.), which contributes so largely to changes in meat, nor the Carnivorous Sarcophagus {Sarcophaga carnaria Meig.), or gray carnivorous Fly, really deposit, even accidentally, their eggs and their larvae on wounds. On the contrary, it is now known — thanks to Portchinskyi — that the majority of larvae which are found in Europe |l<'^ J. Portchinsky. Kranhheiten, wdche in Mohileic'schen Oouvernemcnt von den Lar- ven der Sarcophila Wohlfarli entstehen, und deren Biologie. Horae Societatis Entomo- logicae RussicEe, XI. Saint-Petersburg, 1875-76. Fig. 10.— Head of the Blue or Flesh Fly, highly magnified.— Delafond. a, antennae ; p, maxillary palps ; t, proboscis. DIPTEROUS PARASITES OF THE SKIN IN THE LARVAL STATE. 41 on the wounds of Man or animals, are those of the magnificent Sarco- phagus (S. magnifica Schiner, Sarcophila Wohlfarti Portch.), which, according to Laboulbene, has the following description : Length 10 mm. to 33 mm. General colour ash-gray ; face and sides of head white ; antennae and palpi black ; thorax ash-gray, with three black longitudinal hnes ; abdomen light-gray, with three black spots on each segment. Wings hyaline, base yellow. Legs black. Like all the Sarcophagi, this one is viviparous ; the females deposit their larvae in wounds on Man and animals. These larvae are fusiform, with very distinct segments, and destitute of spines ; the buccal extremity is furnished with two hooks ; the posterior extremity shows two stigmata (or spiracles) — openings of the respiratory apparatus. Fia. 11. — Blue Flesh-fly, natural Fig. 12. — Sarcophaga magnifica, male. — size. — Railliet. Laboulbfene. ' This Diptera,' says Portchinsky, ' is entirely rural, and is never seen in houses. In the perfect state, it is difficult to find, and it can only be procured by hatching the nymphse obtained from the larvae gathered on animals' wounds. It is one of the finest of the Sarcopliila, a,nd it is not only very annoying to Man, but also to animals, in the Government of Mohilew. In fact, I have obtained the Sarcophila Wohlfarti exclusively from different larvae derived from Cattle, Horses, Pigs, Sheep, Dogs, and even domestic Birds — chiefly Geese. In certain years, the infection of Cattle by the larvse of Flies extends to two- thirds, or to at least one-half of a herd. An insignificant wound is suddenly invaded by these larvae, and it soon becomes considerable. This species prefers the mucous membranes, but more particularly the inguinal region of Cows, where the larvae cause extremely serious sores ; this occurrence is frequent here. With Dogs, the same larvae are often met with in the ears, and it is not rare to see them at the same time punctured by legions of Stomoxys calcitrans and covered with blood.' Megnin mentioned having found the larvae of this Fly not only in wounds of the domesticated animals, but also in the depressions or folds of skin where the sebaceous secretion is always in a state of more or less ammoniacal fermentation — such as the lacuna of the frog of the Horse's foot, the cavity of the prepuce, or hollow of the pastern 42 TREATISE ON PARASITIC DISEASES. of that animal. In these places the larvae finish by inducing ulcera- tion of the skin, and they may even sometimes penetrate beneath it, causing more or less considerable disturbance. After their transformation into nymphoe, Megnin has, by hatching them, always obtained the same Fly— the Sarcophaga magnifica. He is of opinion that it is these larvae which are most frequently found in wounds in Man, and that if they are mistaken for those of the Calli- phora vomitaria, Sarcophaga carnaria, and Lucilia Ccesar, it is only because they all resemble each other so much that they cannot be distinguished from each other, except by hatching the perfect Insect — which is i-arely successful. The genus Lucilia (Macq.) contains Flies with a soft proboscis ; the epistoma — the superior border of the buccal cavity — is not salient ; the antennae to the third article are quadruple the size of the second, and the stylet is very plumose ; abdomen short and round, wings wide apart. These characters, joined to the bright metallic colours, constitute a fades which distinguishes this genus from all the others. The Lucilia Caesar (Linn.) is the type ; it is of a fine golden-green colour, is widely extended, and deposits its eggs on decomposing organic matter. It lays them also on the wounds of Man or animals. The Lucilia sericata (Meig.) much resembles it. It is smaller and of a greenish-blue tint. The epistoma and face are white, while the first is of a pale red in the Lucilia Caesar. The first ring of the abdomen alone is black, while in the other species the second ring, in addition, has a black dorsal Hne. In Holland, the Lucilia sericata often causes an affection of a certain gravity in Sheep, which the breeders designate the ' worm sickness ' (Worm-ziekte). It was first studied by Bouman and by Gerlach, then by Jennes and Van Laev.^ The larvae are found chiefly in young Sheep, and especiall}^ those suffer- ing from diarrhoea ; adult Sheep being seldom troubled by them unless they are badly kept. Attracted by the faecal matters about the hind- quarters of the animals, the flies there deposit their eggs, and from these issue small cream-coloured larvae, formed of ten to twelve rings, with points on their borders. The head has two hooks, and the posterior extremity, more voluminous, shows three stigmata. These larvae attack the skin and cause itching, which compels the animal to keep its tail continually in motion, and to bite and rub itself against surrounding objects. The wool is then very closely matted and in hard 1 Bouman, translated by Demarbaix. Annales de Med. Vet., 1863, p. 78. — Gerlach. AUgerneine Therapie d. liausthierkrankheiten, cited by Zurn. — Jennes et van Laer. Dermatof^e ParasUciire chez leu Moutona produite pai- (es larvts de la Lticilia sericata. Journal de Med. Vet. et de I'EltJve du Betail, 1864 ; et Aunales de Med. Vet., Bruxelles, 1867. DIPTEKOUS PABASITP^S OF THE SKIN IN THE LAKVAL STATE. 43 patches, beneath which the skin is perforated by small openings or is largely abraded, and a thick viscid fluid of an unpleasant odour is discharged from it. When exposed, the larvte are greatly disturbed, run away in every direction, and try to conceal themselves beneath the derma. They are sometimes found towards the croup. If the disease persists, it complicates the diarrhoea, and contributes to bring about marasmus in the young animals.^ (This condition is observed among lambs in the United Kingdom, which are said by the shepherds to be affected with the ' fly ' or ' maggot.') Another better-known species is the Lucilia macellaria (Fabr.), more frequently designated the L. hominivorax (Coquerel) and L. an- throjjoj^haga (Conil.). It measures 9 mm. to 10 mm., and is recognised by its blue thorax streaked with three darker blue bands of a purple tint ; the pads are black, and the wings brown at the base. The larva measures 14 mm. to 15 mm. This fly is met with over a great portion of America, from the north of the United States to the- Argentine Eepublic ; but more particularly in the warm regions. It is redoubt- able because of its larviE.- It deposits its eggs in the wounds of the domesticated animals and Man, and even introduces them into the natural cavities. By means of their two buccal hooks, the larvce attack the tissues and rapidly produce serious disorder, with loss of substance and mutilation. The facts published with regard to this too interesting insect are chiefly con- cerning Man. Liguistiu-' has, nevertheless, observed extremely grave complications caused by the larvai of this Lucilia in wounds, and more particularly in the ulcerations (crevasses, cracks or fissures) from which the Horses and Mules suffered during the (French) expedition to Mexico. The last species of this group of parasites is the Ochromyia anthropophaga (Blanchard). Eailliet,'* who has particularly studied it, thus describes it : ' A fly of a grayish-yellow tint, measuring 8 mm. to 19 mm. long. The head is testaceous and covered with small black hairs ; the style of the antennte is plutoose. The thorax has, in front, two black longitudinal bands ; the wings are slightly smoky. The abdomen is covered with somewhat large black spots, particularly behind. * It is a Senegal Fly, met with principally in the Province of Cayor — hence the designation of Cayor Fly by which it is generally known. It has been seen sometimes to hover over animals (Notaris) ; never- theless, it appears to deposit its eggs in the sand. In any case, it is observed that the larvte, known by the improper name of Cayor worms, * We do not know if an analogous afifection to the Worm-ziekte, which has been observed in Sheep by Austrny, veterinary surgeon at Cajarc (Lot), should be attributed to the L. sericata. It differs from it so far, that the animals attacked were previoinly in perfect health, and that the larvae are scattered over different parts of the body — princi- pally the loins, sides, and shoulders. Emaciation was rapid, and death soon ensued. ^ (In Paraguay, foals are sinl to die in large numbers from the effects of larvcc which hatch out of eggs depo.-ited ou the navel before it has dried up. ) * Lignistin. Jnurnal de Med. Veterinaire Militaire, ill., 1865, p. 663. * Eailliet. La Mouche de Cayor. Bull, de la Soc. Cent, de Med. Vet., 1884.— Lt-noir. Mouche et Ver du Cayor. Archives V^terinaiies, 1884. 44 TREATISE ON PAKASITIC DISEASES. develop beneath the skin in Man and various animals — Dog, Cat and Goat. With the Dog, which is more particularly affected, a small inflammatory tumour is seen, which increases rapidly, and is covered by a brown crust. In about six or seven days the larva has completed its evo- lution, and leaves this tumour in order to be transformed into a pupa, cicatriza- tion of the wound being spontaneously _ effected. Fic;. 13.-The Cayor Fly, magnified ' When the parasites are few in two diameters.— Railliet. number, they occupy the tail by pre- ference, as well as the paws and ears — parts in contact with the ground. But if, on the contrary, they are numerous, they are found on all parts of the body. Young animals are oftenest attacked, but adults may be so seriously invaded as to succumb. What is remarkable is that this parasite abounds at Mount Pal, twenty miles from St. Louis, while it has never been seen at the latter place; and what i§ more, Dogs which enter St. Louis covered with larvte are free from them in about two days.' E. Blanchard considers the Cayor Fly as belonging to the family of CEstridae, and allied to the Hypodermae and Dermatobia (see p. 46). Prophylaxis and Therapeutics. — The prophylactic measure to be opposed to myiasis, consists in preventing the approach of the flies, and has been sufficiently indicated in the preceding chapter. In the case of wounds, and in view of their usually small dimensions, it is advan- tageous to apply some empyreumatic oil — such as parafiin — around them : its strong and persistent odour allows of its employment in very small quantities. It is evident that dressings carefully performed, and sufiiciently fre- quent, will prevent the invasion of wounds by larvas ; and thorough cleans- ing will expel them from the parts (prepuce, frog, pasterns) where they have taken up their abode. Keeping the wool of the Sheep clean will prevent the visits of the Lucilia sericata ; and as for the Cayor Fly, the prophylactic measure, says Lenoir, is preventing dogs from lying on the sand, or, better still, keeping them away altogether from the usual haunts of that insect. The curative treatment is very simple, for the larvae are very sensitive to an infinity of agents that cause but little irritation to the wounds that harbour these pests, which otherwise are easily killed or expelled. So that they may either be removed immediately, or the parts may be dressed with ether, chloroform, benzine, petroleum, tincture of camphor, etc. Larv^ of THE (EsTRiD^.i— Although the larvae of the CEstrida ' Numan. Mini, sur les Larves d'CEstres qui sijournent ilans I'estomac du Cheval, 1834. Translated by Verheyen, Biblioth. V^terinaire, vol. I., I'aris, 1849.— Joly. Jie- r.herches mir les (E.strideK. Annales de la Soc. Roy, d'Agriculture de Lyon, 1846.— Brauer. Monographic dtr (Estriden, Verhandl. d. K. Zool. -botanik Gesellsch. in Wien. XII., 1863. DIPTEROUS PARASITES OF THE SKIN IN THE LARVAL STATE. 45 cuticolcs infest the subcutaneous connective tissue, their study natur- ally comes in here, for their presence is associated with perforations of the skin. An essential characteristic of the CTlstridaB, is the necessary parasitism of their larvae. Guided by a special instinct, the female lays her eggs on the bodies of Mammalia, choosing the species to which their future development is subordinate. In order to be hatched, the larva employs various means to reach the organ or region most suitable. Sometimes it is the subcutaneous connective tissue, as for that which is about to be described ; and in other instances it is the frontal sinuses or pharynx, the stomach or intestines. It remains in its special habitat for a variable period, generally from the summer until the following spring ; when it contrives to leave it by a mode of procedure appropriate to each type, and buries itself in the ground, conceals itself beneath a stone, or seeks the shelter of some place which is a little damp, where it may become transformed into a nympha or pupa, before appearing in its perfect state. The latter is generally somewhat rare to find. The (Estridae are recognised by the following zoological characters : Body usually hairy ; head somewhat voluminous and hemispherical ; two facetted eyes, usually separated by a wide forehead which bears three ocelli ; antenna very short, fixed near the forehead, and folding into two corresponding cavities which are completely or incompletely separated. Of their three articles, the last, which is almost globular, has a dorsal bristle or stylet, inserted near the base, and usually single. Proboscis generally very small, or scarcely visible ; two palpi some- times distinct, sometimes rudimentary ; thorax large, elevated, and prothorax very marked ; wings large ; abdomen formed of six apparent rings, the extremity being rounded in the males, and terminated by a very extensible oviscapt in the females. Certain species are viviparous, bringiug forth the larvae already hatched ; others are oviparous, laying eggs of different shapes, with a resisting shell sometimes operculated, which always present at its pos- terior pole an appendage that serves to attach the egg to the skin or to the hair of the host. The number f larvae or eggs which each female deposits is always considerable. The bodies of the larvae are composed of twelve segments, the first two of which — cephalic segments — are not always very distinct from each other. Between these two first segments are two very small respiratory stigmata — anterior stigmata — in the form of points, nodules, or minute slits; these are sometimes concealed in a depression in the integument. The last segment has also two stigmata — the posterior — consisting of openings into which the tracheae may project, or in large peritremes pierced with a variable number of openings. At their birth the larvae have external buccal organs, formed chiefly of two hooks, which are sometimes per- sistent, or disappear as development progresses. Above these buccal organs are seen two small horny or cutaneous projections, which repre- sent the antennae. The anus is very small, and is situated below the 46 TREATISE ON PARASITIC DISEASES. Btigmatic plates of the last ring. During their parasitic existence, the larvae undergo two moultings, which divide this period into three When the larva has quitted its host and reached a place favourable to its nj'mphosis, its skin becomes hai-dened, and is detached from the body of the nympha, the covering of which is supple, and to which it sometimes remains united by four trachece. The shell, more volumi- nous than the insect which has to leave it, is distended at its posterior part by fluid that afterwards escapes. The nymphal state continues from three to eight weeks, and even longer if the weather is cold. When hatched, the Insect, by means of a vesicle which is developed on its forehead, makes such pressure on the inner surface of the shell as to cause this to rupture at the cephalic extremity, and in the direction of the sutures of its arches. The wings of the newly-hatched creature are extended in ten to fifteen minutes. In this perfect state, with their mouth atrophied, the Q^stridse appear to be no longer able to take food; they may live, nevertheless, for several weeks on the fat accumulated in their bodies. Quiescent until their reproductive organs have attained their maturity, they then ex- hibit an extreme vivacity, particularly if atmospherical conditions are favourable. They fly chiefly during the warmest and finest days of summer, and during the middle of the day, and they generally frequent pastures in the vicinity of woods. According to the particular habitat of the larvae, the latter and the species to which they belong are distinguished, since the time of Bracy Clark, as gastricoles or chylivor- ous — gastric or intestinal ; cavi- coles or lyvq^hivorous — those frequenting the cavities of the face; and cuticoles or inirivores — those which are subcutaneous. Fig. 14.— Wing of the Ox Hypoderma, Brauer, whose works on the magnified five diameters. (EstridiE constitute him an au- thority, has arranged all the species into thirteen genera, only four of which — HyjMclerma, Dermatobia, Cnterebra, and CEstromyia — are cuti- cole larvae. Of these four genera, the first two alone develop their larvae beneath the skin of the domesticated animals, in Europe or other parts of the world, and are consequently only those which will be noticed here. From a zoological point of view, they belong to the group whose wings have a terminal transverse nervure (Fig. 14). Hypodermse. — The European cuticole CEstrae belong to the genus Hypoderma (Latr.). In the perfect state, the body of these Insects is hairy ; the head is generally larger than the anterior part of the thorax ; the antennae are very short, and the stylet nude and deeply buried in two separate de- pressions. The proboscis is quite rudimentary ; the thorax is almost spherical, and generally larger than the abdomen. In the female, the DIPTEKOUS PARASITES OF THE SKIN IN THE LARVAL STATE. 47 ovipositor (Fig, 16) is long, consists of four articles, and is continuous with the fifth segment ; the segments composing it pass within each other in a telescopic fashion. When it is extended it projects backwards and slightly upwards, and at the end of the last article are three horny appendages, a little curved inwards toward each other like pincers, between which the eggs pass out. The wings, most frequently fuligin- ous, are small, divergent, and inclined outwards. In the first stage, the larvae are free in the subcutaneous connective tissue, in the panniculous carnosus, and in the superficial muscles. The skin covering them does not show any perforation, this being obHterated after giving passage tp the young larvge. The duration of this period appears to be several months. At the end of this time the larva is about 13 mm. long ; it is nearly cylindrical in shape, and only about 2-2 mm. thick. The mouth, which is altogether anterior, has^ above, a salient stylet, completed on each by a hook curved almost at a right angle. These hooks can be brought together so as to become parallel to the median stylet, and thus form a point well adapted to bore through the tissues, while by their separation they are opposed to withdrawal and facihtabe progression. It is doubtless by this mechanism that the newly-hatched larva can penetrate beneath the skin. This larva is formed of eleven rings; it is white except at the mouth, pharynx, and posterior stigmata, where it is brown. The stig- mata consist of thin, porous plates of chitin, which do not yet perfectly fulfil their role of respiratory openings. This function must be accom- plished partly by the skin — which is thin, almost transparent, and nude — if it is not carried out in the infundibuHforrn depression of the mouth and on the border of the lower lip, where there are two microscopical spines. In the second stage, which occupies about two months, the larva increases in dimensions in every direction, but preserves its white colour except at the inferior surface, where there are three black spots formed by agglomerations of microscopical spines. The upper surface is nude, with the exception of the first two or three rings. The mouth is V-shaped and circumscribed by plates of chitin; the stylet and hooks have disappeared. The plates of the posterior stigmata are reni- form and have large alveoli. The posterior extremity is thin, the anterior expanded and vesiculous. The third stage lasts two to three months. The larva becomes thick, pyriform, and almost spherical in a state of contraction ; it has the shape of a boat when elongated, being convex below and plane above. Soft, flexible, and very contractile, it becomes yellow, then brown, and finally black. The buccal fossette is infundibuliform, with the rudi- mentary antennas above it. At the upper surface of the cephahc extremity, is a slight horseshoe-shaped furrow that extends to the fourth ring. This furrow encloses the part which, at the termination of nym- phosis, is detached by the Insect in the form of an operculum. Each ring, from the second to the ninth, carries three pairs of lateral ridges ranged beside each other and garnished with spines, the disposition'^of which varies according to the species ; the last ring is hemispherical or cylindrical. Three kinds of Hypodermaj whose larvae are parasitic in the 48 TREATISE ON PARASITIC DISEASES. domesticated animals, are actually known : the Striped Hypoderma, the Beindcer Hypoderma, and the Bovine Hypoderina. The latter belongs more particularly to this country, and has been the longest recognised. The Striped Hypoderma {H. lincata Villers) is black, very hairy, 12 mm. or 13 mm. long, and derives its name from the gray, longitudinal bands on the upper surface of the thorax. It has been found in England, Norway, Germany, Italy, Southern Russia, and in Kentucky, America. Brauer supposes that its larva lives beneath the skiu of the Ox, and that it must be included among the larvae of the OEstridae which have been several times observed in Germany beneath the skin of Sheep recently clipped. The Beindeer Hypoderma forms the sub-genus (Edemagena (Latr.), which is only distinguished from the Hypoderma^ by the latter having no palpi, and the spines on the surface of the larvae being fewer on the lower than on the upper surface ; while in the (Edemagena the palpi — small and globular — are present, and the two surfaces of the larvae are equally spinous. The Hypoderma of the Eeindeer {H. {(Ed.) Tarandi Linn.) is black and very hairy. The female — larger than the male — is 16 mm. long. The thorax is covered with yellow hair, and has a wide, black, trans- verse band. The first segment of the abdomen is covered with pale- yellow hairs, the other segments with short hairs. The thighs are black : legs and tarsi grayish-yellow. The larva is in every way larger than that of the Ox Hypoderma, which it much resembles in other respects. This species is found in Lapland and North America. Linnaeus states that it inspires so much fear in the Reindeer, that ten of the Insects will alarm a herd of more than five hundred. As soon as they appear, the Eeindeer tremble, run about, snort, bellow, and stamp their feet. He also mentions that the female — as with the other Hypodermae— only deposits its eggs on the skin of these animals. Once hatched, the larva penetrates beneath the skin of its victim, and is there nourished after the manner of the Hypodermae. The Insect deposits its eggs early in July, when the Reindeer has shed its coat. It prefers to attack young animals, though it does not spare the old ; it pursues them in the valleys, among precipices, and even on the icy mountain-tops. In their agitation, the Reindeer can scarcely settle down to feed, and it is not uncommon to see them lying down all the day before the hut of their owner, without attempting to eat, in order that the thick smoke issuing from the habitation may preserve them from the attacks of the (Edemagena. The larva) are, however, not numerous on the same animal, being six to eight on young deer ; but their presence causes much emaciation, and sometimes they are blamed for destroying as many as one-third of these (N. Joly). The Ox Hypoderma {II. bo vis Degeer) is by far the most interesting of the cuticole species, for it is abundant in this country, and extends from Scandinavia and North America to the south of Europe, and to Asia and Africa. It has the following characters (Fig. 15) : Black, very hairy. Face gray, with white or yellow hairs. Similar hairs on anterior half of the upper surface of the thorax, black on the DIPTEBOUS PARASITES OF THE SKIN IN THE LAEVAL STATE. 49 posterior half, and marked by wide longitudinal bands of shining black, close together. Abdomen black, covered with white or yellow hairs at Fig. 15. — Hypoderma of the Ox. A, Female, natural size. B, Larva making its exit from a tumour. — Reaumur. its base, black in the middle, reddish-orange in its posterior third. Legs black at the base, yellow in their terminal moiety ; wings some- what brown. Length, exclusive of the ovipositor, 13 mm. to 15 mm. In its perfect state, this insect lives during the months of July and August, and may even be met with in the first days of September. It B ^AAAAa A/'aaaA A^AaVaaAAAAA A A A A A aAA^'^^^V^ ^A AAAAAAA ^A AAA AAA f\ aaAa aaA^ AAAA AA :^^%, Fig. 16. — HjT)oderma of the Ox. A, Extended ovipositor, magnified.— Reaumur. B, End of this ovipositor, highly magnified : e, spines which cover the outside of the second-last tube of the ovipositor ; V, vulvar tentaculae ; c, middle piece of 4;he spoon. — N. Joly. is particularly well known, from the fact that it can be artificially hatched when the larva is extracted from the Ox's skin and kept in favourable conditions. The female is provided with a soft, short, black, 4 50 TREATISE ON PARASITIC DISEASES. cylindrical oviscapt, which is folded beneath when the Insect is resting, and which serves to deposit its eggs on the skin of bovines while they are out of doors. It prefers the upper parts of the body— the shoulders, back, loins, croup, sides and flanks. Its flight is rapid and accom- panied by a buzzing sound. When it is about to lay its eggs, it flutters above the back of the Ox for a minute or two, then suddenly drops, deposits an egg on the skin, rises in the air, again flutters, descends with the like rapidity as before, and drops another egg. This manoeuvre is repeated ten or twelve times in a quarter or half hour. It is a widespread belief — which the majority of authorities have subscribed to — that the approach of the female Hypoderma causes great terror among cattle : they are restless, become more and more agitated, and finally start off in a frantic manner, with tail horizontal, until beyond the sound of their enemy. Sometimes they plunge into water to shelter themselves from the dreaded pursuit ; and in this way accidents may occur. This fear is contagious, and one Hypoderma will put to flight a whole herd ; it is even sufficient, it is said, to closely imitate the buzzing of the Insect to realize the same moral effect, and to this trick is often attributed the panics among Cattle which occur at fairs. Virgil is considered the first writer who has described the fear that the G5strus inspires in herds (' Georgicorum,' lib. iii.) ; but it is more than doubtful that the Insect which he mentions belonged to the family of OEstridae ; and, on the other hand, doubt has been thrown upon the correctness of the popular behef which, from the time of Virgil, has been transmitted to our own day. It is really founded on the dread the Ox may experience, of the puncture the female CEstrus makes on inplanting each egg in the skin. But it is well established that the oviscapt (ovipositor) of the CEstrus is not adapted in any way for boring, and is merely a depositing apparatus ; consequently, egg-laying does not cause any pain to the host. Bracy Clark first, and Hertwig afterwards, remarked on this fact ; and, besides, Goudot, who has personally experienced the effects of the larvae of the Dermatobia, asserts that he never heard or saw the Flies, much less felt them deposit their eggs on the uncovered parts of his body, and is inclined to attribute the fear of animals on the approach of the Dermatobia, to an instinctive prevision of the future trouble that awaits them. On the other hand, it may be asked if the share the Hypoderma have in causing fear among Cattle is well founded, or if it is not rather due to their not being able to discriminate between the buzzing made by the Insect and that of the Gadflies, Breeze-flies, Wasps, and other Diptera which torment animals under the same circumstances — that is, in hot and stormy weather. Although Brauer, who is responsible for the statement, says that two females of the Hypodcrvia Actaon have been seen depositing their eggs on the backs of Deer without these appearing DIPTEROUS PARASITES OF THE SKIN IN THE LARVAL STATf. 51 to notice them, yet he is careful not to draw an inference from one species to another. On the contrary, he brings forward a document to prove that here, also, popular observation cannot be relied upon with- out an imposing array of facts to support it. It is a letter from Schleicher, an intelligent farmer of Gresten, Austria, who had seen the perturbation caused by the Hypoderma, and was able to capture the Insect in the act of laying, forwarding it to Brauer, who recognised it as the female of the Hypoderma bovis, with an egg still between the pincers of its oviscapt. It is probable that the ova are deposited on the skin itself, or at the hair-roots ; but no one has seen them there. Those who have described the eggs have obtained them directly from the female, by slight pressure on the abdomen. Fig. 17.— Hypoderma of the Ox. A, Genital apparatus of the female : ov, ovaries : pc, copulative pouch ; do, oviduct ; 6iip, a louse) has been given to the cutaneous affection due to the presence of Lice on the surface of the skin. It is also named the Pedicular disease and Lousiness. In its ordinary sense, the term Louse comprises all the apterous parasites which do not jump like Fleas, and only by accident quit their host. With the exception of the Melophagus of the Sheep and some doubtful species, all belong to the sub-order of Hemipterous parasites, Bhynchotes parasites, and the Pediculince. of Piaget. These are small-sized — only a few milhmetres in length — apterous insects, of a dull- white colour, and the mouths of which are adapted either for pricking or masticating. The head bears two simple eyes, or ocelli, often but little distinct; and two antennas, composed of three, four, or five articles. The three thoracic segments are more or less confounded with each other. The abdomen is usually composed of nine segments. The legs are ordinarily short and strong ; the tarsi are formed of two articles, the last of which has two nails, or booklets, by which the insect can creep. The eggs, called nits, are pyriform, have an oper- culum at one end, and are fixed very solidly to the hairs or feathers by a glutinous substance. The young — which leave the eggs by the operculum — have quite the shape of the adults, and do not undei-go any metamorphoses, though they only acquire their definitive colour and consistency after several moultings. The male and female differ from each other, in the former being a little smaller than the latter, frequently by peculiarities in the antennae, by the last abdominal segment being often divided in the female and rounded in the male, which has also, on the middle line, a copulating apparatus of a brownish colour, and digitform or lancet- shaped. The males are usually much less numerous than the females. The Hemipterous parasites are divided into two families — the Pedicu- lidce and the Bicinidce. 1 Piaget. Les Pedirulines, Leyden, 1880 ; SuppUment, Leyden, 1885. — Taschenberg. Die Malhphaijen. Nova Acta des Kls. Leop.-Carol.-Deutsch. Acad., XLIV., Halle, 1882. - Railliet. Art. Phthiriase, Porix. Nouv. Diet. Prat, de Med., de Chir. et d'Hygicne Vetcriiiaires, XVII., 1889. 5 66 TREATISE ON PARASITIC DISEASES. The PediculidcB, or Lice properly called, have the mouth arranged as a sucker at the anterior border of the head ; the tarsi always terminate in a single claw, with the exception of the Hccmatomyzus, which has two. The Bicinida, Ricitii, or Mallophagcs, have the buccal apparatus formed for mastication ; they are pcllivorous — that is, they live on epidermic productions, hairs {pilevorous\ or feathers {pennivorous) ; the pieces constituting the mouth are placed at the inferior surface of the head, and the tarsi terminate in one or two claws. PEDICULID.^. — These have a movable proboscis, formed of the upper and lower lips, and armed in front with one or two verticilli of small spines. In this canal are four channels, arranged two and two, the juxtaposition of which form an internal tube, or sucker, narrower and longer than the canal. The insect projects this sucker beyond the sheath to bury it in the skin, and uses it to aspirate the blood. The booklets, or spines of the sheath, fix the aspiratory apparatus, and so prevent access of air. The thorax is small, but usually larger and shorter than the head, and shows scarcely any traces of its division into three segments. The abdomen is generally elliptical in outline, and has its last segment rounded in the male, with an opening which the penis can pass through ; in the female this segment is notched or bilobate, with two small terminal appendages. All the known species live on the Mammalia. The Lice infesting Man — the head Louse {Pediculus capitis), body Louse {Pcdiciilus corporis), and pubic Louse or Morpion {Pediculus pubis) — belong to this family : genera Pedicidus and Phthirius. The species which are found on the domesticated animals are all included in the genus Hcematopinus (Leach). Haematopinus. — The Insects in this genus are not very distinct from the genus Pediculus, the species of which are comparatively few, Fig. 25.— Magnified posterior extremity of the Haematopinus of the Pig.— Delafond. A, Male dorsal surface. B, Female ventral surface. and live, two on Man and a third on a Monkey. The Haematopinus are characterized by their head being inserted directly on the thorax, without any constriction like a neck ; by their antenntc of five articles, their abdomen of eight or nine segments, their tarsi with a single claw, and their legs without a distinct appendage at the internal angle of their tarsal extremity (Figs. 25, 26, 28, 29, 34, 36, 37, 40). The Haematopinus are found on all the domesticated Mammalia, with the exception of the Sheep, Cat, and Guinea-pig. PHTHIKIASES. 67 RICINID^. — These Insects are often distinguished at first sight from the PedicuHdae by their head, which is always larger than their thorax, and the shape of which is determined by a system of dark horny bands, to which particular names are given. The most important are : 1. The antenncal hands, which are marginal, and border the head in front, from the insertion of the antennae, joining or not joining each other in the middle line ; 2. The occipital bands, which extend — one on each side — from the occiput, or posterior border, to the base of the mandibles or orbit. The mouthpieces are situated on the inferior surface, and are principally constituted by the mandibles, in the form of short hooks, and by the jaws. The thorax generally has its prothorax distinct, but its other two segments are usually joined as one, which receives the name of meta- thorax. The first seven abdominal segments have their borders strengthened by a lateral baiid, and most frequently have transverse spots. The masticatory apparatus of the Eicines allows them to subsist on epidermic productions, and fragments of hairs or feathers. They do not suck the blood of their hosts like the Pediculidae ; so that they might be considered not as true parasites, but as commensuals which free the skin from its scurf. But it must not be concluded that they are really advantageous to the animal infested by them. Not only do they soil the skin by then- dejections, their ' nits,' their exuviae, and their dead bodies, but it is certain that their contact is felt by the creatures on which they live, and on which they produce disagreeable itching, accompanied by sharp bitings. Birds invaded by these vermin are often in bad health. The Eicines are divided into two sub-families : 1. The PhiloptermcB, which have the antennae composed of three or five articles, and have no maxillary palpi ; 2. The LiotheincB, whose antennae have four articles, and which are provided with quadri-articulated maxillary palpi pro- jecting beyond the anterior border of the head. Philopterinae. — Independently of the above characters, it is neces- sary to note in these Insects the frequently important development of the anterior part of the head, which is named the clypeus, and is some- times distinctly separated from the posterior part by a suture. The antenneal sinus is a more or less deep notch on each side of the middle line of the head, and at the bottom of it is a small protuberance that carries the antennae. The Philopterinae are divided into eleven genera, only six of which are of interest to us. These are : the Trichodectes, which live exclu- sively on Mammalia ; the Ornithobia, Lipeures, Gonoides, Goniocotes, and the Docoplwres, which are parasitic on Birds. The Trichodectes (Nitzsch) are characterized by their three-articled antennae, these having five in all the other genera. They are limited to Mammalia, the other genera being special to Birds (Figs. 27, 30, 31, 35, 38, 39). The Ornithobia (Ornithobius Denny — Fig. 49) and the Lipeures {Lipeurus Nitzsch — Fig. 46) have a narrow, elongated body, the sides 5—2 68 TKEATISE ON PARASITIC DISEASES. being nearly parallel. The antennae are different in the two sexes ; besides, iu the Lipcurus the third article in the male has an appendage which is absent in the Ornithohius. The latter has the abdomen bordered on each side by two parallel bands, while there is only one on the Lipcurus. The Ornithobia are special to the Swan. The Goniodes (Nitzsch — Fig. 43) and Goniocotes (Nitzsch — Figs. 44, 45) have the body flattened, sides rounded, or an elongated oval, and the antennae different in the two sexes, the first article in the male being larger than the others. In the male Goniodes the third article, and sometimes the first, has an appendage which is absent in the Goniocotes ; and the latter always has the abdomen rounded at the end, while in the male Goniodes it sometimes has two points. The Docophores {Docopkorus Nitzsch — Fig. 48) have the antenna) the same in both sexes. They are inserted in the sinuses or excavations at the sides of the head, which has two strong movable trabecular at its anterior angle. The Liotheinse are distinguished from the Philopterinoe by their four- articled antenna) and distinct maxillary palpi. The head is very broad at the temples, and aj)pears to be triangular or ti'ilobate. In front of the temple there is often a notch, called the orbital sinus, in which is found the eye, though this is usually not very distinct. The Liotheina; comprise ten genera, four of which have their repre- sentatives on the domesticated animals. These are Gyropus, Trinoton, Colpocepl ledum, and Mcnopon. The Gyropes {Gyropus Nitzsch — Figs. 41, 42) have only a single claw at the tarsi, wliile there are two in the other nine genera. The head presents, posteriorly, two notches, limiting the very salient temples. They are only met with on the Mammalia, and principally Eodents. The Trinotons {Trinoton Nitzsch) have the head very round in front, the temples sahent and projected backwards ; a wide orbital sinus, having at the bottom a bilobate eye ; and the antennae short and con- cealed. The thorax is divided into three distinct segments, and the tarsi have two claws. This Insect lives exclusively on Palmipeds. The Colpocephales {Colp)Occphalnm Nitzsch) have the head wider than long — somewhat like that of the Trinotons ; but they are distinguished from them by their rarely bilobate eyes, and antennae projected beyond the head. The tarsi have two claws. They live on all kinds of birds except the Coursers {Charadriidct). The Menopons {Mcnopon Nitzsch — Fig. 47) generally have the head like that of the two preceding genera, but the orbital sinus is absent or very shallow at the part occupied by the eye, and often also that where the antennae are fixed ; the latter are always short and indistinct. Living on Birds of all kinds except the Coursers, Piaget has on two occasions found them on Mammals — one of them, the Mcnopon cx- trancuvi, on the Guinea-pig. This summary zoological description being considered sufficient to enable anyone to recognise the genus to which a parasite belongs, it will be easy to determine its species by the following information. PHTHIKIASES. 69 Horse. — The horse harbours the Hcematopinus macrocephalus, the Trichodectes pilosus, and the TricJwdcctcs imhcsccns — the latter less frequently than the other two.^ Haematopinus macrocephalus (Burm. — Fig. 26). — Head elongated and narrow; antennas implanted on a kind of lateral protuberance, behind which is a deep notch, lodging the eye at the bottom. At this part the temples are wide and curve forwards ; then the head contracts, and assumes a triangular form in its posterior moiety. The thorax is much shorter than the head ; the abdomen is oval, with continuous and slightly sinuous borders ; the two stigmates on the margin of each ring are placed in the middle of a lateral protuberance. The head and Fig. 26. — Hci'inatopinus macrocephalus, female, of the Horse ; magnified twenty diameters. — Railliet. Fig. 27. — Trichodectes pilosus, female, of the Horse ; magnified twenty diameters. —Railliet. abdomen are &i a grayish-yellow colour, and the thorax a brown maroon. The length of the female is 3-6 mm. ; that of the male 2-6 mm. Trichodectes pilosus (Giebel — Fig. 27). — The head is wider than it is long, and is rounded in front — a little widened at the temples ; the antenneal band makes a turn around the forehead. The first seven segments of the abdomen have middle quadrangular spots. The head, thorax, legs, and abdomen are covered with hair on both surfaces, and, in addition, the last abdominal segment on the male has two hairy cushions. The general colour is yellow ; spots and head ferruginous ; baud brown maroon. The length of the female is 1-9 mm. ; that of the male 1-6 mm. Trichodectes pubescens {T. parumpiloms Piaget). — This Insect is much rarer than the preceding ; it is -2 mm. less in length, and differs chiefly in the head, which is hairy only along the borders. Ass. — The Hcematopinus of the Ass belong to the same species as that of the Horse, but Piaget makes it a different variety — Colorata — a little larger than the type, head less hairy, tint darker, and with a quadri- 1 G. Neumann. Sur un pseudo-parasite du Cheval (Trichodectes quadricornis Gay). Revue V^t^rinaire, 1890, p. 78. 70 TREATISE ON PAEASITIC DISEASES. lateral spot on the sternum. The Trichodectes pilostis is also a parasite of the Ass. Ox. — On the Ox there are found the Hcematopinus curysternus, the H. tcmnrostris, and the Tricliodcctcs scalaris. Haematopinus eurysternus (Nitzsch — Fig. 28).— The head is rounded in front, slightly elongated — more in the male than the female. It is, besides, cbietly distinguished from the H. macroccphahis by its oval and very large abdomen, having on each segment a slightly-coloured lateral tubercle. The head and thorax are fawn-coloured, the latter being darkest ; the abdomen is yellow or grayish ; the genital spot is dark. The female is 3 mm. long, and the male 2-5 mm. Hsematopinus tenuirostris (Burm.— Fig. 29).— Rarer than the pre- ceding, the head is elongated and somewhat buried in the thorax ; the latterls as broad as it is long, and the abdomen is narrow — scarcely wider at the sixth segment — the largest — than at the first. The general tint is a deep chestnut, brighter on the forehead, legs, and the lateral band of the abdomen. The female is 3 mm., and the male 2-5 mm. long. It is probably this species that Linnaeus found on sucking calves, and named Pedicuhis vituli. It also infests adults, perhaps as much as C£tlv6S. Trichodectes scalaris (Nitzsch— Fig. 30).— The head is scarcely so wide as it is long, is almost parabolic in shape, and is very hairy. Fig. 28. — Hoematophius euryster- 'FiG.29.—Ha;7iiatoi>i>nu^ Fig. 30. — Tricho- nm, female, of the Ox ; magnified tenuirostris, female, of dectes scalaris, fe- twenty diameters. the Ox; magnified male, of the Ox; twenty diameters. magnified twenty diameters. — Rail- liet. It resembles Tr. 2yilosiis, but it has not the hairy cushions on the last abdominal segment, and the median spots are larger. The general colour is white, the spots ferruginous, the bands being darker. The length of the female is 1-5 mm. PHTHIEIASES. 71 Sheep. — The Pediculincz are only represented on the Sheep by the Trichodectes sphserocephalus (Nitzsch — Fig. 31). It has the head as broad as long, rounded in front, the antenneal band turning round the forehead, which has long hairs at the sides. The antennae are hairy and sHghtly longer in the male than in the female ; the median spots on the abdomen are sub-quadrangular. The general colour is white, spots and head ferruginous. The length of the female is 1-7 mm., and of the male 1-4 mm. The phthiriasis of the Sheep is usually due to the Melophagus ovinus (Lat.), which belongs to the Pupiparous Diptera (see p. 36), but which, being apterous, does not quit its host, and multiplies in its fleece ; it is nourished on the grease (yolk) of the wool, the debris of hair, and the blood that it causes to flow by its bites ; consequently, it lives Uke the Pediculinae. Macquart formulates its characteristics as follows : ' Head disengaged from the thorax. Palpi elongated, fluffy, and inclined downwards. Antennae nude and in the form of tubercles. Eyes very small and close ; no ocelli. Thorax somewhat narrow ; abdomen oval. Feet downy ; tarsal claws bi-dentated. "Wings null.' The general colour is ferruginous ; abdomen grayish-brown, and irregularly spotted. Length of body, 3 mm. to 5 mm. Goat. — The Haematopinus of the Goat is the Haematopinus stenops {H. stenopsis Burm.— Fig. 34). Fig. Z\.— Trichodectes sphcerocephalus, fe- male, of the Sheep ; magnified twenty diameters. Fig. 33.— Proboscis of the Melo- phagus ; much magnified. — L. Dufour.* Fig. 32. — Melophagus of the Sheep; magnified. The line on the left indicates the natural length. * a, Proboscis ; b, its free extremity ; c, basilar enlargement, with the muscles inserted into it ; d, horny spines, also furnished with muscles. The head is elongated, narrow, conical, round in front, notched later- ally, and widened at the temples, in the form of a gourd, acuminated in the thorax, which is scarcely concave on the abdomen ; the latter is an elon- gated oval in shape, bearing two terminal appendages; stigmates nearly 72 TREATISE ON PARASITIC DISEASES. marginal. Colour straw-yellow, gray for the abdomen. Length of female 2 mm., male 1*5 mm. Several species of Trichodcctes have been described as living on the Goat, but only one, the Scaly Trichodectes {Tr. climax Nitzsch — Fig. 35), is well established. The head is scarcely as wide as it is long, and is quadrilateral, having in front a broad but shallow notch, at which the two antenneal bands stop ; the antennce are longer in the male than in the female, the first article being thicker and shorter than the others, and the second longer than the third. The abdomen has median spots, which diminish in breadth as the length increases ; the last segment in the male has two hairy cushions. The head and thorax are reddish-brown in colour, and the bands dark. The female is 1-8 mm., and the male 1-3 mm. long. This species lives on the common as well as the Angora Goat. The Pic. 34. — Hcnmatop'mns -fenopsis, female, of the Goat ; magnified twenty diameters. Fig. 35. — Trichodectes cUmar, female, of the Goat; magni- fied twenty diameters. Fig. 36. — Hannatopinua uriiis, female, of the Pig; magnified about nine dia- meters. — Delaf end. Insect that Gervais figures and describes as the Tr. Umhatiis is evidently the Tr. climax, though Piaget appears to identify it with his Tr. climax var. major, found also on the Angora Goat, and the female only of which differs slightly from the type, scarcely in dimensions. With regard to the form vaguely described and figured by Gervais as Tr. climax, it appears to us to correspond to none of the known species. According to Taschenberg, Tr. caprce (Gurlt) and Tr. solidus (Endow) of the Guinea Goat, and probably Tr. mambricus (Rudow) of the Levant Goat, are identical with Tr. climax. Taschenberg has also recognised that Tr. crassipcs (Rudow) of the Angora Goat is none other than Tr. penicillatus (Piag.), found by Piaget on a Kangaroo [Macropus penicil- latus). But this might be a case of wandering parasites on an abnormal host. Camel. — The Haematopinus of the Camel {H. cameli Redi), which has only been seen by Redi, much resembles that of the Pig. PHTHIRIASES. 73 Pig. — The Pig nourishes only the Hsematopinus urius (Nitzsch, H. suis Linn. — Fig. 36). This species is the largest known amongst the Pediculinge. The head is very long and narrow, rounded and conical in front, with five hairs on each side, and towards the sucker three other long hairs. The temple has a very salient sharp horn on the first article of the antenna, and it gradually contracts to the occiput, which is rounded to its thoracic suture. The abdomen is an elongated oval, very developed, with continuous borders ; the stigmates are on a prominent lateral pro- tuberance. The head and abdomen are yellowish-gray in colour, the stigmatic spots and thorax a maroon-brown, and legs fawn-tinted. The female is 5 mm., and male 4 mm. long. Dog. — The Dog has one Hsematopinus and one Trichodect. Fig. 37. — Hcematopimis pUi- ftrus, male, of the Dog ; magnified twenty dia- meters. YiG. 3S.—Trichodectesla(u.% Fig. 39. — Trichodectes male,of the Dog; magnified sttbrof:tratus, female, of twenty diameters. — Rail- the Cat; magnified liet. twenty-five diameters. Hsematopinus piliferus (Burm.— Fig. 37). The head is short and almost as wide as long ; it is salient in the thorax to which it is exactly applied ; the third and fourth articles of the antennaj are alike. The abdomen is very developed in the female, and is a long oval in shape ; it has nine rounded segments, which are often sahent at the sides ; stig- mates distinct and marginal ; the first seven segments have two rows of short bristles. The general tint is yellowish- white, the head and thorax being a little darker. The female is 2 mm. long, and the male 1"5 mm. Trichodectes latus (Nitzsch — Fig. 38).— The head is sub-quad- rangular and much wider than it is long, being truncated in front ; the antenmr! are hairy, and different in the two sexes, the first article in the male being much thicker, and occupying a moiety of the length of the organ. The abdomen is broad and more rounded in the female, with lateral, but no median spots. The colour is bright yellow, spots darker ; the bands on the head are blackish-brown. Length of the female 1'5 mm., of the male 1-4 mm. Ferret. — There is sometimes met with on the Ferret, and in great numbers, the Hsematopinus piliferus, which lives on the Dog. 74 TREATISE ON PABASITIC DISEASES. Rabbit. — The only Louse found on the Eabbit is the Hsematopinus ventricosus (Denny— Fig, 40). It is rare. The head is subuHform, broader than long, coMstricted behind the antennce, widened at the temples, where it is rounded. The thorax is wider than the head, and is concave on the abdomen ; the latter is oval, as broad as long, bulging, rough, and hairy. The head, thorax, and legs are of a bright chestnut colour ; the abdomen is of a dirty- white. The length of the female is 1-3 mm. and of the male 1-2 mm. Guinea-pig. — The Lice of the Guinea-pig belong to two species of Gyropes (Figs. 41, 42). Gyropus gracilis (Nitzsch). — This is recognised by its long, narrow- abdomen, especially in the male ; by its head, made, as it were, trilobate Fig. 40. — Ha'matopimis ven- tricosus, male, of the Rab- bit ; magnified twenty-five diameteris. Fig. 41. — Gyropus gracilis, female, of the Guinea-pig; magnified twenty-five diameters. Fig. 42. — Gyropus ovalis, male, of the Guinea-pig ; magnified twenty -five diameters. in front of the antennae ; by the notch at the temples ; and by its antennae, the fourth article of which is globular, and rests on the third as an elongated peduncle. The general colour varies from dirty-white to ochre-yellow. The length of the female is 1-2 mm., and of the male 1 mm. Oval Gyropus {G. ovalis Giebel). — This differs by its large, oval ab- domen, crenulated on the borders, and garnished with two rows of hairs on each segment. The head is shorter and wider. The general colour is white ; the spots, tarsal bands, and claws are dark. It is of the same length as the Gyroi^us gracilis. To these must be added the Menopon extraneum (Piag.), found once by Piaget, and of which mention has been already made (p. 68). Birds maintain a larger number of Pediculi than the Mammalia, and these parasites all belong to the family of Eicinidae (see p. 67). Each species of Eicinus is not strictly localized on a particular host, but many are common to several kinds of Birds. On the other hand, the promiscuousness of the poultry-yards, and, above all, of the markets, may lead to erratic parasites passing to a Fowl from a specifically different host. Fowls. — The parasites found on Fowls belong to the four genera of Goniodes, Goniocotes, Lipeurus, and Menopon. PHTHIKIASES. 75 Goniodes dissimilis (Nitzsch— Fig. 43).— The head is wider than it is long, and rounded in front ; it is smaller in the male. The antennce of the male — double those of the female — has the first article most I IG. 43. — Goniodes dissimilia, male, of the Fo wl ; magnified twenty diameters. — Piaget. Fig. 44. — Goniocotes holo- Fig. 45. — Goniocotea gi- gaster, male, of the Fowl ; gas, female, of the Fowl; magnified forty diameters. magnified ten diameters. developed, and has a long hair at the inner side. The temporal angles are salient, especially in the female, but do not form horns. The antenneal band is very strong, and wide in front, with a series of distinct fissures for the implantation of hairs. There are five bristles at the posterior border of the metathorax. There are also two median bristles, and three or four at the angles of each abdominal segment, with an arched marginal spot ; at the ven- tral surface of the abdomen of the female, there are two little bands in Fig. 46. — Lipeurus variabilis, male, of Fig. 47. — JUenopon pallidum, female, of the Fowl ; magnified twenty diameters. the Fowl ; magnified twenty diameters. — Railliet. the form of a T laid sideways. The general colour is a dirty- white, the spots darker, and the bands fawn-tinted. The length of the female is 2-5 mm., and of the male 2 mm. This is one of the most frequent parasites. 76 TREATISE ON PARASITIC DISEASES. Packard has observed on the Fowl a Goniode of Burnett {Gd. Burnetii Pk.), which is probably allied to Goniodes dissimilis. Goniocotes hologaster (Nitzsch — Fig. 44). — The head is as wide as it is long, the anterior border rounded and slightly convex, the an- tenneal band being wider in front. The abdomen has unicoloured quad- rangular lateral bands, curved and broader towards the suture, and wider on the ventral than the dorsal surface ; the transverse patches are faint, but distinct ; the sutures are only visible between the first three segments. The general tint is a dirty-yellow, deeper at the thorax ; the bands are brownish. The female is 1-3 mm., and the male -8 to -9 mm. long. Taschenberg has noticed a variety (var. maculata). Goniocotes gigas (Tasch. — Fig. 45). — This is recognisable by its round and very large abdomen, marked on each segment by long, trans- verse, tongue-shaped spots, coloured only on their border. It has, besides, proportions which are quite exceptional in this genus. The general colour is yellow ; the abdomen and metathorax are brighter coloured, and the bands and outline of the spots are dark. The female is 4 mm., and the male 3 mm. long. Lipeurus variabilis (Nitzsch — Fig. 46). — The head is round in front, and in the male is wider in its anterior portion, at the temples in the female ; it is margined in front by the uninterrupted antenneal band. The first article of the male antennae is longer than the other four put together, and has a strong obtuse excrescence. There is a middle spot beneath the thorax ; the female has a genital, lance-shaped spot, and the last ring of the abdomen is bilobate. The general colour is a pale yellow, the spots being a deep fawn-tint and the bands black. The female is 2'2 mm., and the male 1*9 mm. long. Lipeurus heterographas (Nitzsch). — The head is parabolic in front, very wide behind the eye, and limited anteriorly by the uninterrupted antenneal band. The metathorax is as long as the prothorax. The abdomen is an elongated oval, slightly larger in the female, with six short bristles implanted in tubercles on each segment in the male, and median spots on each ring and bristles on their borders. The general tint is pale yellow, spots fawn-coloured, bands black. The female is 2 mm. long, the male being 1-8 mm. Menopon pallidum (Nitzsch — Fig. 47). — The head is slightly angular in front and somewhat crescent-shaped, the temples being bent down- wards ; the latter are short and rounded, with four bristles and some hairs ; there is no appendage to the second article of the antennae. The thorax is longer than the head in the female ; they are equal in size in the male. The pads are strong and hairy. The abdomen is an elon- gated oval in the female, narrower and longer in the male, with a single series of bristles on each segment. The general tint is a dirty-yellow, the spots on the abdomen being a bright fawn-colour. The female is 1-7 mm. long, and the male 1-8 mm. Menopon biseriatum (Piaget). — This is rendered distinct from the other by its head, which is markedly parabolic in front, by the presence of two series of bristles on each ring of the abdomen, and by the eighth segment, which is, in the male, elongated and narrow. It has the same tints as the preceding. The female is 2-7 mm. in length, the male 2-9 mm. This Insect lives also on the Turkey, Pheasant, and Pigeon. Turkey. — The parasites of the Turkey belong to the genera Goniodes, Lipeurus, and Menopon. PHTHIRIASES. 77 Goniodes sty lifer (Nitzsch). — The head is as wide as it is loDg; it is quadrangular, especially in the male ; the temporal angle forms a long horn, acuminated behind and terminated by a bristle. The metathorax has divergent sides, acuminated on the abdomen, and bearing iive bristles on the posterior border. The seven first segments of the abdomen show linguiform spots on the sides, and which cover the transverse third of the segment ; in the middle of each there is a bright Bpot occupied by the stigmate ; there are numerous hairs on both surfaces. The general colour is dirty-white, the spots are fawn-coloured, and the bands brown and black. The length of the female is 3 mm., that of the male 3-2 mm. Lipeurus polytrapezius (Nitzsch). — The head is relatively short — it is strongest in the female — scarcely so wide at the temples, and very rounded in front, where it is bordered by the uninterrupted antenneal band. The first article of the male antennae is thick, fusiform, a little longer than the other four collectively, and is provided with a strong excrescence at its base. Beneath the thorax there are two median spots, the second of which extends for a short distance on the abdomen. The female has an acuminated genital spot posteriorly, and the last abdominal segment is deeply notched. The general colour is yellow, spots fawn-tinted, and bands black. The length of the female is 3 mm. to 3-7 mm., and of the male 2-8 mm. to 3-7 mm. The Menopon of the Turkey is the M. biscriatum, which lives also on the Fowl. It is probably the same as the M. stramineum (Nitzsch). GuiNEA-FowL. — A Goniode, a Goniocote, and a Menopon live on the Guinea-fowl. Guinea-fowl Goniodes {Gd. numidianus Denny). — The head is longer than it is wide ; the antennaB of the male are somewhat long, and have the third article curved and acute, carrying the succeeding two beyond its axis ; the eye is salient, and occiput a little suppressed. The meta- thorax is wider than the head and acuminated on the abdomen, with a black band at the posterior border ; the legs are strong. The abdomen is oval, with the spots twice interrupted. Its length is 1-7 mm. It has been found by Denny on the Guinea-fowl. There has also been found on this Bird the Goniodes stylifcr. Goniocotes rectangulatUS (Nitzsch). — This differs from Gouioc. Jiolo- gastcr of the Fowl chiefly in the lateral bands of the abdomen, which are wide on the ventral surface in this Insect. The segmental sutures are only distinct between the three first. The length of the female is 1 mm., and of the male -8 mm. This insect was found on a Guinea- fowl by Taschenberg, but it is rather a parasite of the Peacock. Lipeurus of the Guinea-fowl {L. numidcc Denny). — The head is large, subpanduriform, rounded in front where it is bordered by the antenneal band, and wide behind the eye ; the female antennai have the second article very long. The metathorax is nearly as wide as the prothorax. The abdomen is oval, the first seven segments showing a double series of spots, which form two interrupted dorsal bands. The colour is livid yellow, and the bands and spots black. The length is 21 mm. This insect was found on the Guinea-fowl by Denny, who considered it a Nirmus [Nirinus monida) — he probably had not seen the female. (Eailliet.) 78 TEEATISE ON PAKASITIC DISEASES. Menopon of the Guinea-fowl {M. numidce Gieb.). — The head is semilunar, and the orbital sinuses distinct. The prothorax is large, with three sharp points at each angle ; the metathorax is large and trapeziform. The abdomen is also large, with festooned borders garnished with bristles and dark spots. The general colour is red. Length 1 mm. Peacock. — The parasites of the Peacock, like those of the Guinea- fowl, belong to the genera Goniodes, Goniocotes, and Menopon, Goniodes falcicornis (Nitzsch). — The head is nearly square, and curved somewhat downwards in front, especially in the male ; the antenneal band is narrow anteriorly and has parallel borders ; the temples are angular, and do not form a horn behind ; the occiput is scarcely depressed ; the first article of the male antennae is very thick, is nearly as long as the other four, and has a strong appendage on the inner side ; the third article has a long curved appendage ; the other two are thin, and rest on a protuberance from the third. The meta- thorax is not so large as the head in the female, but in the male it is as large, or larger, than the prothorax. The abdomen is very large, and on the sides has very dark-coloured languiform spots. The genital apparatus of the male is very large, and ascends to the third segment. The general colour is yellowish- white, the spots being a deep-fawn hue. The female is 3-3 mm., and the male 3 mm. long. This is a common para- site. Small-headed Goniodes {Gd. i)arviceps Piaget). — This differs from the preceding principally in the head, which is more regularly quad- rangular ; in its metathorax, which is larger than the head ; in its abdomen, which is scarcely so large as the metathorax ; and in the dimensions of the male and female, which are 2 mm. long. Goniocotes rectangulatus (Nitzsch). — This is the same as those which are found on the Guinea-fowl. Black-mouthed Menopon {M. plueostomum Nitzsch).— The head is elongated, contracted, and rounded in front, very wide at its posterior border, and the temples narrowed and bent downwards. There is no appendage to the second article of the antenna. The thorax is longer than the head, and the metathorax a little rounded on the abdomen ; the latter is a long oval in the female and larger than in the male, with a single series of bristles on each ring. The general tint is yellow, brightest in the male ; the spots are fawn-coloured. The female is 1-6 mm., and the male 1-3 mm. long. Pheasant. — The common parasites of the Pheasant are the Goniodes, Goniocotes, Lipeures, and the Menopons. Goniodes of the Pheasant {Gd. colchicus Denny). — This differs from the G. disswdlis of the Fowl chiefly in the presence of a small tooth at the inner side of the antenna of the male, of only two bristles at the posterior border of the metathorax, and in numerous median bristles on each segment. The dimensions are about the same. Goniodes truncatus (Giebel). — The head is large and parabolically rounded in front ; the temples are not excavated, nor prolonged pos- teriorly as horns ; the occiput is convex, and the occipital angles acute. The abdomen is an elongated oval, that of the male is truncated behind ; PHTHIRIASES. 79 the lateral bands are arched, and because of this a short appendage on them is pushed into the preceding segment. The colour is white, with dark bands. The female is 3 mm., and the male 2-4 mm. long. Gonicotes chrysocephalus (Giebel). — This differs chiefly from Gc. rectangulatus of the Guinea-fowl and Pheasant, in having the sutures between the eight first segments of the abdomen visible. The colour is yellow, particularly at the head and thorax. The female is 1-2 mm., and the male "8 mm. long. Lipeurus variabilis. — This parasite of the Fowl has also been found on the common Pheasant by Taschenberg and Railliet. Long Menopon (3/. productum Piaget). — This differs from M. palli- dmn of the Fowl principally in having the temples less excavated, and the body being elliptical and constricted to the sixth segment in the female, and nearly as short as broad in the male, with the ninth segment short and like a reversed ogive. The general tint is ochre-yellow, fawn-coloured on the sides of the abdomen. The female is 1-8 mm., and the male 1-5 mm. long. Biseriated Menopon. — This is the same as that found on the Fowl and Turkey. Among the parasites found on the Silver Pheasant, are placed the Goniocotes chrysocephalus of the common Pheasant, and a variety of the Menopon phceostomum, the type of which lives on the Peacock, The Golden Pheasant offers, amongst others, the Lipeurus hetero- graphus — described for the Fowl, and the Menopon prodiLctum of the common Pheasant. Pigeon. — On the domestic Pigeon there have been found : a Goniode, Goniocote, Lipeurus, Colpocephalus, and two Menopons. Dwarf Goniode {Gd. minor Piaget). — All the species have the abdomen oval and broad, but this is distinguished by the antennae of the male, the last two articles of which are very reduced and scarcely visible ; and by its metathorax, which is rounded on the abdomen. The colouris yellow, and the female is 1-7 mm. long, the male being 1-4. mm. Companion Gonicote {Gc. compar Nitzsch). — The length of the head is a little less than its width at the posterior border ; the anterior border is convex, and the antenneal band linear. The abdomen is oval and rounded in the female, truncated posteriorly in the male, and has coloured spots only on the border of each segment ; each margin of the abdomen has two parallel bands. Colour a dirty-yellow. The female is 1-4 mm., and the male 1 mm. long. Rod-shaped Lipeurus {L. baculus Nitzsch). — The head is elongated and very narrow, the anterior part — clypeus — being round and separated from the other portion by a constriction ; it is not bordered in front by the antenneal band, and is garnished by six fine hairs and two claviform appendages. The first article of the male antenna is much thicker than the others, and has an enlargement at its base, but has no appendage ; the third article has a strong lateral appendage. The prothorax is quadrangular, and one-third shorter than the meta- thorax. The colour is dirty-white, with bright yellow spots and brown bands. The female is 2-1 mm. to 2-3 mm., and the male 1-8 mm. to 2 3 mm. long. Long-tailed Colpocephalus (C. longicaudatus Nitzsch). — The occi- 80 TREATISE ON PAKASITIC DISEASES. pital bands are not distinct. The abdomen of the female is conical, and bordered by narrow dark bands ; the first segments are the longest, and the ninth is elongated and constricted at its posterior moiety, as well as fringed with long and fine hairs ; in the male the abdomen is an elongated oval, and the last segment is rounded and garnished with numerous long bristles. The insect is white, with fawn-coloured spots. The female is 1-6 mm., and the male 1-3 mm. long. Broad Menopon {M. latum Piaget). — The head is parabolic, and nearly angular in front. There is an appendage to the second article of the antenna) in the two sexes. The thorax is longer than the head in the female, shorter in the male ; the metathorax is not so broad as the head, and is rounded on the abdomen. The latter is large, oval, and rounded in the female, and oval and elongated in the male, with salient angles. The colour is yellow, with bright, fawn-coloured spots. The female is 8 mm., and the male 1-5 mm. long. GoosE. — The parasites of the domestic Goose belong to the genera Docophorus, Lipeurus, and Trinoton. Bilious Docophorus (-D. icterodes Nitzsch). — The head is as wide as it is long ; the clypeus is semicircular, with a triangle on each side, and at the lower surface a constricted elongated spot. The prothorax is not so wide as the metathorax. The abdomen is bordered on each side by a uni- formly white band ; the first segment has an inter- rupted transverse band on the median line ; the others have a wide lateral band, leaving free the middle third ; the last is simply notched in the female. The colour is brown. Length of female 1-8 mm., and male 1-3 mm. It is frequent on Ducks and relatively rare on Geese, on which it constitutes, according to Piaget, a mere variety that Nitzsch has named Docophorus adustus. Lipeurus jejunus (Nitzsch). — The head is Fig. 48.— Docophorus elongated, and the clypeus is colourless, rounded, Drck^'^^naiTified Separated by a constriction and a suture, not twenty-iivo dia- bordered in front by an antenneal band, and gar- meters, nished by six fine and two spreading hairs at the suture. The prothorax is subtrapezoidal, and has a spot at the posterior angle, which projects laterally ; the metathorax is twice as long, with a large tubercle at the posterior angle, on which are implanted four short bristles. The colour is dirty- white, spots dark fawn, and bands black. The female is 3 mm., and the male 2-5 mm. long. Lipeurus anseris (Gurlt). — The head is elongated and conical, rounded in front, with the clypeus analogous to that of the preceding species. The metathorax is double the size of the prothorax, and is constricted at the sides. The colour is white, with dark spots. The dimensions are the same. Trinoton conspurcatum (Nitzsch). — This is a very large species. The head is as long as it is wide, and is exceeded in front by the last two articles of the palpi, showing on each side two enlargements," the posterior of which — the temple — has five bristles. The thorax is longer than the head, and rounded on the abdomen. The legs PHTHIBIASES. 81 long, and garnished with hairs and bristles. The abdomen is oval, not so wide at the base as the metathorax, and the angles are salient ; the first eight segments have a series of bristles fixed in colourless tubercles. The colour is white, the spots brown maroon, bands black, thorax dark, head bright-fawn tint. The female is 6-3 mm., and the male 5*8 mm. long. This parasite was found by Denny on the Goose, but it is more frequent on the Swan. Trinoton continuum (Piaget). — This insect has four bristles at the temples, the abdomen has slightly salient angles, and is more downy on its two surfaces, while there are fewer hairs on the legs. The dimensions are also less, being for the female 6 mm., and for the male 56 mm. long. It is, probably, only a variety of the preceding species, and is more common. Duck. — A Docophorus, Lipeurus, Trinoton, and a Menopon have been found upon the domestic Duck. The Docophorus icterodes, described as infesting the Goose, is very common on the Duck. Lipeurus squalidus (Nitzsch). — The head is narrow, elongated in front of the antennae, and suddenly constricted at the suture of the clypeus ; the latter has a spot — signature — parallel to the border, and rounded posteriorly. There are six hairs on the forehead, two of which are on the clypeus, the second being very flat ; in front of the mandibles there is a round and small fossa ; the temple is round, and has one bristle and a spine ; the antenneal bands stop at the suture of the clypeus, and do not go beyond it in front. The metathorax is not so wide at the head, is slightly longer than it is broad, and is a little concave on the abdomen. The latter has a narrow, uniformly wide, black band on each side ; the transverse fawn-coloured spots are more or less apparent. The general colour is fawn yellow. The female is 2-8 mm., and the male 2-5 mm. long. This parasite is very common, and Taschenberg has found it on the Barbary Duck. Pale Trinoton (T. luridum Nitzsch). — This more especially differs from the T. conspurcatuvi of the Goose, by the presence of only four bristles at the temples ; the metathorax is concave on the abdomen, the latter having segments rounded at the sides ; narrow transverse spots^ interrupted in the middle on the first two segments, and surrounding a colourless circle on the side ; and the bristles not having a wide base. The colour is white, with maroon spots and black bands. The length of the female is 5-4 mm., and of the male 4-7 mm. Dark Menopon {M. ohscurum Piaget). — The head is crescent- shaped and strong, with the temples broad and turned downwards, and the lateral borders nearly as long as the thorax. The abdomen has dark, narrow, lateral bands without appendages. The colour is dark fawn. The length is 1-4 mm. to 1-5 mm.^ Swan. — Independently of the Trinoton conspurcatuvi, which lives on the Goose, the domestic Swan — Cygyms olor — has an Ornithobius. Ornithobius bucephalus (Giebel). — The head is massive, nearly as ^ Piaget only gives one host for this speciea, the Anas radjah, but we have found it in abundance on a domestic Duck. 6 82 TREATISE ON PARASITIC DISEASES. broad as it is lonf;, irregularly quadrangular, and shaped anteriorly like a pair of closed forceps ; the antennic are strong and carried forward ; the posterior part of the head is divided into three portions by the two occipital bands, which, at first parallel, converge forwards towards the root of the mandibles. The thorax is narrower, and a little shorter than the head. The abdomen is oval, and nude except at the angles ; the lateral bands are very narrow. The colour is white, with pearly transparent bands. The length of the two sexes is 35 mm. to 4-5 mm. Symptoms.^— Phthiriasis is mani- fested in all animals by signs of itching, the intensity of which is sub- ordinate to the numbei of parasites, and the group to which these belong. The Haematopinus, the rostrum of which is formed for pricking, and which attacks the substance of the skin to feast on the blood and humours exuded as a result of this pricking, causes a much more intense pruritis than that occasioned by the Eicinus. The locality of the pruritis naturally indicates that of the para- sites, which are also betrayed by their eggs — these being less deeply situated among the hair or feathers — and like- wise by the cUbris the insects leave after moulting. „.„,,.,,,., , , , Horse and Ass. — The haeraatopinic tiG. 49. — Ornitnobius bucephalus, msXe, , , , __ -, . ^ of the Swan ; magnified fifteen dia- phthinaSlS of the Horse and Ass has "^***'^"- its principal seat at the mane and I'orelock, but more especially at the root of the tail, or in the neighbourhood of these parts. The animal seeks to rub itself against everything within its reach, gently bites its neighbours, and allows itself to be bitten and rubbed by them. On entering a stable, it is easy to recognise animals so affected, by the erectness and matting of the hairs, especially at the root of the tail ; and a careful examination will readily reveal the presence of the HtTcmatopinus and its eggs, along with numerous epidermic pellicles — constituting true pityriasis. When grooming has not been carried out for some days, the dead dried bodies of parasites, and the exuviae of their moultings, increase the general aspect of uncleanliness. The papules which some authors have described are rarely observed, but only various excoriations due to rubbing. Eaillet has seen an old mare ' which showed on the back little tumours caused by elevation of the epidermis, beneath which were numerous masses of Haematopinus.' ^ M^gnin. Les Parasites et les Maladies Paradtaires, Paris, 1830. PHTHIKIASES. 83 Trichodectic phthiriasis is less common, and not so prm-iginous ; but with this exception, it resembles the preceding, from which it is dis- tinguished by examining the parasite. The Trichodectes are not often found on the upper parts of the body, but the two phthiriases may, though rarely they do, co-exist on the same Horse. Ox. — The same symptomatic differences are remarked between the hffimatopinic and trichodectic phthiriases of the Ox ; but, contrary to what is observed in the Horse, the latter appears to be the most fre- quent. The Trichodectes are spread over the whole body, while the Haematopinus prefers the ears, back of the head, upper border of the neck, and middle of the back and loins. The prmitis impels the animal to rub itself against trees, posts, or salient parts of its dwell- ing, and with its rough tongue it scratches the skin ; consequently, there are large hairless patches, and often an abundant epidermic secretion with — though very exceptionally — thickening of the skin, which may mislead as to the true nature of the malady. Sheep. — The Sheep Lice are concealed at the bottom of the fleece. The presence of the Melophages is indicated by the pupae, which are attached to the indi^ddual fibres, and appear as shining oval bodies, not unlike the small pip of an apple in colour and shape. In separat- ing the wool, the parasites are found close to the skin, and when they are numerous the fleece is entangled, and some- times absent in places. These insects attract the attention of Starhngs and Wagtails, which hover about flocks of sheep, and perch familiarly on their backs in order to feed on the-'^'^*^- ^^ parasites. Pupa of the Melophagus of the Sheep, at- The Melophages often emi- '^^'^^"^ *° *^^ Fig. 51. — Magnified pupa of the Sheep Melopha- gus, seen on its dorsal surface, and showing two series of seven umbilicated points. end of a lock of grate from suckling ewes to the wool. lambs, which they sometimes torment so much as to cause serious emaciation. If the fleece is short, in order to avoid the teeth of their victims, the parasites take refuge in front of the shoulders, on the neck, and particularly about the ears and horns. By their biting they produce great itching which makes the sheep gnaw themselves, scratch their bodies with their hind-feet, and rub against anything within reach. At the places where the Insects have been biting, on separating the wool, a red patch the size of a lentil is seen, in the centre of which is a darker spot. The Trichodectes are less frequently observed than the Melophages, perhaps because of their smaller size. They may in certain cases seriously alter the wool ; for its shedding appears to be due to the 6—2 84 TBEATISE ON PARASITIC DISEASES. cutting they effect by their mandibles at the root of the fibres, accord- ing to the observations of Railliet.^ The Trichodectes induce severe itching, and the wool is more or less altered, broken, and matted in places. There also are seen bright red spots from 8 mm. to 10 mm. in diameter, covered by thin furfuraceous scales, formed of epidermic ddhris and dried serosity. The Tricho- dectes are easily found, hanging on by means of their claws and jaws to the wool fibres on and around these places. According to Delafond,^ these parasites are much more common on lean, debilitated, or badly nourished Sheep than on vigorous and well-fed ones. Pig. — This animal is greatly incommoded when invaded by the Haematopinus. The species infesting it is the largest of all the family, and causes a pruritis proportionate to its size. The skin is marked by red papules of various dimensions, and is often excoriated. The itching is most severe at night, and the animal rubs itself eagerly against its sty or trough, rolls in the litter, or even demolishes its habitation. Sequens'^ relates that of 140 porcelets, 40 — aged from one to two weeks — succumbed to an intense phthiriasis affecting all the pigs. The disease lasted four or five days. At the autopsies, besides signs of anaemia, there were found numerous excoriations and ulcerations on various parts of the body, the knees and hocks were inflamed, and even the capsular ligaments were involved — all the result of the pruritis which had killed these young pigs. The disease ceased when parasiticide and disinfecting agents were had recourse to. Viborg was a witness to similar occurrences, which led him to declare that the Haematopinus may pass to beneath the skin, and make its exit by the nose, mouth, and eyes. This, so manifest an exaggeration, shows to what an extent these parasites may crowd on the same animal. Dog. — Lousy Dogs do not appear to be much inconvenienced by their numerous parasites. The Hsematopinus torments them more than the Trichodectes, and sometimes to a high degree. Both kinds of parasites are encountered on all parts of the body, but the Haema- topinus is more particularly seen about the throat. Goat. — According to Delafond,"* Lice may live in very great numbers on the Goat, especially in winter. The skin becomes irritated, and the hair falls off, leaving bare places covered with flaky, sometimes thick crusts, beneath which the integument is red and frequently ulcerated. The Haematopinus produces these troubles ; but with Angora Goats the Trichodectes cause great depreciation in the value of the hair. Camel, Cat, Ferret, Babbit, and G-uinea-pig. — The phthiriases of these animals have scarcely received any attention up to the present time, ^ Railliet. Sur le Trichodecte du Mouton. Bull, et Mem. Soc. Cent, de Med. ■V«?t^rinaire, 1883, p. 105. 2 Delafond et Bourguignon. Traitc jwatique de la Pnore. Paris, 1862, p. 488. ^ Sequens, Jahresber. u. d. Veterinarwesen in Ungarn, 1889, p. 100. * Delafond et Bourguignon. Loc. cit.,]). 406. PHTHIBIASES. 85 and their trifling importance or rarity justifies the silence maintained with regard to them. The Trichodectes of the Cat are seen most frequently on young animals debilitated by scabies. The majority of the Guinea-pigs affected have numerous Gyropes concealed in their fur ; their presence is revealed by a yellowish dust at the ends of the hairs twenty-four hours after the death of their host. The oval Gyrops is much less abundant than the small Gyrops, and prefers to localize itself on the head. Birds.^ — Phthiriasis has a much greater importance for Poultry than for the domesticated Mammaha ; as the first are nearly always attacked in a variable degree, and the multiplication of their parasites becomes a real nuisance, causing them to lose their rest, become emaciated, and frequently compromises the rearing of their offspring. Their parasites are found all over the body, though less on the thighs, neck, and head than on the trunk, and especially beneath the wings. It is sometimes the reverse, however; for it at times happens that the head, and chiefly the neck — which cannot be reached by the beak — are particularly frequented by the Lice. Each species of Fowl being capable of nourishing several kinds of parasites, these may be found collectively on the same individual. And as several of the Ricinidae attack very different species, it may be remarked that, by the cohabitation of Fowls, Turkeys, Guinea-fowls, etc., one kind of parasite may be accidentally met with on an illegitimate host. So that here is an affair of erratic parasites, which signifies that they are not multipUable, as they are not accompanied by their ' nits.' Diagnosis. — The diagnosis of the disease is easy, if the size of the parasites is known. It is well, nevertheless, so far as the Mammalia — and especially the Horse and Sheep — are concerned, to be careful not to attribute to Lice affections of the skin which are sometimes coincident with phthiriasis, but are of quite another nature. Such is scabies, the gravity of which is otherwise serious, and which has been occasionally overlooked for some time, because the pruritis — of psoric origin — was ascribed to the Lice. Prognosis. — This is rarely serious, considering the efficaciousness of the numerous remedies we possess. Nevertheless, in certain cases the malady induced is particularly obstinate to cure, especially when ag- glomerations of young or debihtated animals have to be dealt with. Budelot^ relates the history of one enzooty of haematopinic phthiriasis, affecting 119 Horses of a regiment of Artillery, and which prevailed for nearly five months, notwithstanding the parasiticide treatment em- ployed. It is true that, in reading this account, and in estimating the gravity of the cutaneous troubles he observed, one is incUned to ques- tion whether it was not one of those coincidences of scabies and phthiriasis the possibility of which has already been referred to. ^ Ziirn. Die Krankheiten des HamgeMgeh. Weimar, 1882. - Budelot. Journal de M^d. Veter. Militaire, IX., 1871, p. 88. 80 TREATISE ON PARASITIC DISEASES. The troublesomeness of phthiriasis is dependent upon the pruritis which accompanies it. It may happen — at least with cattle — that the loss of hair will temporarily depreciate the value of the animals. Such depilation is damaging to Sheep ; the disease has been known to persist for six years in one flock, and the wool to fall off to such an extent that the animals looked as if just clipped. Birds, and especially Pigeons, sometimes suffer much from the in- vasion of parasites. There are poultry-yards and dovecots where these insects are perpetuated, in spite of all the efforts made to destroy them. Young creatures, particularly young Pigeons, at times succumb to phthiriasis, and breeding is then rendered somewhat risky. When the nests are infested with insects, the Pigeons neglect hatching, and even abandon their young. Etiology. — It is clear that contagion is the primary cause of phthiriasis, and that the multiplication of Lice is due to a succession of prosperous generations, whose origin was due to a contagiferous host of the same species as that now dealt with. It is always possible that two domesticated animals of different species may infect each other — as when the same kind of parasite may live on one or the other, as is the case with the Trichodcctes jpelosus of the Horse and Ass, with the Menopon hiseriatum of the Fowl, Turkey, and Pheasant, with the Goniocotes rectangtdatus of the Guinea-fowl and Peacock, with the Docopliorus icterodes of the Goose and Duck, and with the Trinoton consjmrcatwiji of the Goose and Swan. Beyond these exceptions, the parasites which accidentally venture upon a different species to that of their natural host do not become acclimatized or multiply there, but soon emigrate. Kemmereri has, however, published an observation in which a woman was seized with violent neuralgia of the hairy scalp, and was immediately cured by the ex- traction of an insect fixed in a wound on the head, and which the author recognised as a Trichodect. On another occasion a horse- dealer suffered from erysipelatous inflammation of the arm, and the author found in a small wound a Trichodect, the head of which was buried in the derma (!), the remainder of the body projecting from it. But the symptoms observed were altogether out of proportion to the ascribed cause, and the details furnished do not permit the zoological diagnosis to be accepted. These suspected cases cannot, therefore, be considered of any moment here. Certain conditions favour the extension of the malady, and give to the contagion an unusual activity. Want of cleanliness plays the chief part in this extension. The length of the hair, the abundance of the fleece, is one of the predis- posing circumstances. In addition, debility in the animals gives a ^ Kemmerer, Journ. des Connaissances Medico-Chirurgicales, 1853. PHTHIRIASES. 87 more favourable soil for the parasites, whether this weakness be due to age, breed, temperament, work, food, etc. For example, the Trichodectes appear somewhat more frequently on young Horses, while the Hoematopinus rather favours old ones. Calves are more exposed to Lice than adult cattle, and these insects are rarely found on short-haired dogs, while they are frequent on those which have long frizzly hair. Though two species may live together, the Hcematojjinus ^Ji'Z^/crzfs is more particularly met with on long-haired sporting Dogs, as Spaniels, etc., and the Trichodectes latits on little Lap-dogs with long or frizzly coats, as small Spaniels, King Charles Spaniels, long-haired Terriers, Havana Dogs, etc. It is the anasniic Sheep which are most frequently lousy, and in the instance cited by Eailliet the nursing ewes were more especially at- tacked. According to Villeroy,^ ewes suffer most from the Trichodectes, etc., during the winter, and particularly if it be wet. It is stated, so Stephens asserts, that if lean Sheep are bought to feed on turnips, it is when they commence to fatten that the Melophagus multiplies on them in an astonishing manner. Otherwise it appears to prefer lambs, and on shearing they are sometimes found to be literally covered with the parasite in places at the anterior part of the neck. The Melophages are at times so abundant that they constitute a veritable scourge ; this happens in North America and in Iceland. And yet these parasites are not prolific, for the female only lays one larva at a time, and there are but four or five in the course of the year. These larvae are sacciform, non-segmented, have four lateral surfaces, and measure 3-7 mm. long, 1-9 mm. wide, and 1-6 mm. high. Their buccal parts are alone movable. They become transformed very rapidly into nymphse, even on the body of their host. When the conditions are favourable Lice multiply, on the contrary, at a wonderful rate, the females being very prolific, and growth being rapid. It has been already stated (p. 12) that it has been calculated that the third generation of a Louse of the human head amounts in about twelve weeks to 125,000 individuals, and these calculations do not take into account the numerous causes of destruction which re- strain this multiplication ; they are, nevertheless, instructive in enabling us to understand the cases of excessive phthiriasis. When phthiriasis occurs among Poultry, it is ascribed to feeble nutrition, due to bad or too uniform food, to the influence of damp, dirty, close, dark, and badly-ventilated localities. There are years which are favourable to this disease, and seasons appear to have an influence on its progress, while temperament and breed are not to be ignored. Bechstein, cited by Eivolta and Delprato, states that of two Capuchine Monkeys living in the same conditions, one was invaded by Lice, while they were rare on the other. We have observed the same 1 Villeroy. Recueil de M^cL V^t^rinaire, 1868, p. 9G3. 88 TREATISE ON PARASITIC DIflFAHKS. occurrence in a Bantam Fowl, which was really lousy, while two Gascony Fowls living with it were quite free from parasites. Treatment. — The attention required to be given to animals in cases of phthiriasis, will vary according to whether they are Mammals or Birds. Mammals. — Perfect cleanliness keeps animals clear of phthiriasis. Such cleanhness is easy to realize with short-haired animals, and will rapidly get rid of the few parasites which contagion may convey to them. When phthiriasis is present, a cure will be singularly favoured by removing the hair of the Horse or Ox, as well as of the long-haired Dog, and the wool off the Sheep. With regard to the latter, clipping usually suffices to get rid of the Melophages ; many of these are cut by the shears of the shearer, and those remaining on the skin are soon knocked off by the animal rubbing itself, so that in about two days none are to be seen. Sometimes, however, for them as for other parasites, it is necessary to have recourse to insecticide agents, the number of which is considerable. A. One of the most efficacious and most employed is the decoction of tobacco (2 or 3 ounces to the quart of water). When near a manu- factory of tobacco, the expense is much reduced by obtaining the refuse powder, or the juice, to which ten times the weight of oil is to be added ; though this juice, being rich in ammoniacal matters, has the incon- venience of decomposing rapidly. This treatment answers for all animals. Nevertheless, precautions must be taken ; for the whole body should not be dressed at once, as poisoning may ensue from absorption of the alkaloids of the tobacco. For Sheep the preparation is kept in a bottle, the cork in which is perforated by a quill. As soon as the shep- herd observes a Sheep commencing to scratch itself, he gets hold of it, and seizing its head between his legs, he opens out the wool and pours the fluid on to those places he judges requires it. B. Frictions with fatty bodies, linseed-oil in particular, kill the Lice by asphyxia. Cooking-oil, in which fish have been fried, has been re- commended as especially efficacious. This treatment is more particu- larly applicable to the Pig. G. Mercurial ointment is a certain cure, but its employment is dangerous ; therefore only a small surface should be dressed with it at a time, and it ought not to be used for Dogs, even when they are muzzled, and still less for cattle, which are so sensitive to mercury. Numerous cases of poisoning of animals by means of mercury are re- corded. D. Frictions with a decoction of stavesacre seeds, 2 ounces to the quart of water, and colchicum bulbs in the same proportion. E. Insecticide powder. It is well, beforehand, to damp the skin with soapy water. Then the powder is dusted or blown over the skin ad hoc. The powders of pyrethrum flowers and stavesacre seeds are most generally in use. PHTHIKIASES. 89 F. Frictions with a mixture of 1 part benzine, 6 parts of soft soap, and 20 parts water ; or, better, petroleum 1 part, common oil 10 parts. Employed alone, the benzine, and especially the petroleum, is too active, and may remove the hair. G. Schleg's mixture is recommended in Germany, because of its efficaciousness and harmlessness. It is composed of 1 dram each of arsenious acid and potass, and 3 pints of water, to which 3 pints of vinegar are subsequently added. H. The emulsion of cresyl or creoline— 10 to 15 per cent, water — promises to assume an important place in the treatment of phthiriasis, by reason of its innocuousness and the readiness with which it can be employed. Two or three dressings with it are sufficient. Whatever may be the remedy adopted, it is well to repeat the dressing at intervals of five to eight days, in order to kill the parasites hatched from the eggs, and which have resisted the first dressing. The majority of the eggs are killed by vinegar, and this is the reason why it is so often added to parasiticide decoctions in the proportion of 18 ounces to the quart. For house Dogs, fatty preparations, and in general all those which are hkely to soil furniture or the hair, are to be avoided. For them, frequent baths, and washing with creoline water and carbolized soap, are to be recommended, together with the use of the comb and brush. Lastly, when a number of animals are invaded, independently of the curative measures, disinfection of the dwellings — stables, sheepfolds, pigsties, kennels, etc. — is necessary. Boiling water at first, afterwards limewash, or merely creoline water — 5 per cent. — answers very well. All litter should be destroyed, and dressing of the animals should be performed out of doors if possible. Birds. — There are also numerous means for destroying vermin on Fowls. Flowers of sulphur, or one of the insecticide powders mentioned above, may be used ; they can be blown among the feathers by an instrument ad hoc. As the Fowls in flapping their wings, or the Pigeons in their flight, may shake out the powder, it is a good plan to lubrify the roots of their feathers with soapy water before blowing in the powder of pyrethrum or stavesacre. But individual treatment will not suffice. The floors, ceihngs, walls, perches, and nests are the haunts of parasites, which will soon take the place of those that are destroyed ; and sometimes there is great diffi- culty experienced in finally abolishing them. Schneider^ speaks favour- ably of fumigations with sulphuret of carbon. Small open phials filled with this liquid are placed in the hen-roost or dovecot, at those parts where they are not hkely to be upset, and very quickly all the vermin are destroyed or expelled. This can be repeated whenever a new inva- sion is apprehended. 1 Schneider. Bull, d" Inseetologie Agricole, 1878, p. 56. 90 TREATISE ON PARASITIC DISEASES. Ziirii reproduces an article from'the Dresdener Blatter filr Gcflilgclzucht (No. 39, 1881), in which lime-dust is indicated as a means as simple as it is infallible. In the absence of the Birds, two small handfuls of this is thrown against the roof and walls, so as to produce a cloud of dust. A portion falls into the nests and crevices, and the remainder reaches the ground. The vermin are killed, and in about two minutes the place is carefully swept out, and the sweepings placed on the dung-heap. This measure is analogous to that given in Lc Poussin (1884, p. 86). A peasant took lumps of old plaster from buildings which were being demolished, and placed them on the road, so that the wheels of carriages reduced them to powder : this he threw into the dovecot, where it formed a somewhat thick layer on the floor. The Pigeons scratched and pecked at it, so that they powdered themselves with it and spread it about all parts of the dovecot when they flew. The efi'ect was rapid, for soon there did not remain a single Insect in the dovecot or on the Birds. Besides, the shells of the Pigeons' eggs had acquired more hardness. The procedure which is the most recommended and employed is the following : All the masonry is lime-washed at least twice a year, and everything in the roost is taken out — spars,' perches, nests, etc. — and steeped in water containing 3 drams of carbolic acid to the quart of water. Then with a hand-pump or any similar instrument, throw the water with force upon every part of the interior of the dwelling ; this kills and washes down the insects. After emptying the hen-roost and closing all the apertures, a quantity of powder may be burned therein. .The place should be kept shut up for three days, then opened widely for twenty- four hours before allowing the Fowls into it. The Fowls themselves are advantageously protected against parasites by sand-baths. To form these there should be made in the run, under some kind of shelter, a shallow square hole, which is to be filled with fine sand, cinders, and light soil, with which powdered sulphur is mixed. If the Birds are much troubled with vermin, insecticide powder may be added to this sand-bath. According to the Hausfrauen Zeitung (1889), instead of spreading straw on the floors of the roost, wood wool should be used, or wood chopped up into fine pieces, such as are used for packing. A layer of this is warmer than straw, drives away the vermin by its aromatic odour, does not rot so quickly, and furnishes an almost odourless manure very suitable for clayey, heavy soil. For some time there has been sold an engine named ' Lagrange's Exterminator,' which serves to kill the parasites on the Birds them- selves. This is a wooden box into which the Bird is introduced with its feet tied, its head being kept outside by a special opening. In the box a brimstone match is burned, and five minutes of this vapour bath sufiices to kill all the parasites.^ 1 E. Leroy. L'Eleveur, 1890, p. 358. PHTHIRIASES. 91 Lastlj', it may be mentioned that there is another means, somewhat insufficient, but very often adopted, and which consists in putting into the roosts a branch of alder-tree. The Lice, attracted by the odour, gather upon it, and next morning early the branch is carefully removed and burned outside. This is repeated until there are no para- sites. Independently of the parasites mentioned, and those to be alluded to hereafter, some Insects may accidentally torment Birds, and form part of their vermin. The Fowl, and particularly the Gosling and Duckling, are sometimes attacked by small Dipteras, which pass into their nostrils and ears. They may be protected by some one of the remedies already noticed, or, better, by a de- coction of walnut - leaves — 2 ounces to the quart of water and 5 ounces of vinegar added ; or by assafoetida — 4 ounces to the same quantity of water and vinegar as in the preceding. With this the threatened parts should be impregnated. In unclean roosts and dovecots there are sometimes large numbers of Bugs that belong to a particular species — the Dove-cot Bug {Acanthia columbaria Jenyns) — closely allied to the Bed Bug {Acanthia lectitlaria Linn.), which is so well known. These Bugs exhaust young animals by sucking their blood, and fatigue them by the itching they induce after the bites. According to Eailliet, hens hatch- r u i^ i ing are so tormented by these Insects that ^'^^^.-Bug of the l owl. they finally abandon their eggs, on w^hich are ^^ Natural size. B, Mag- then seen small specks formed by the excre- nified. ments of the Bugs.^ Pigeons also suffer from the larvae of the Eermestes lardarius (Linn.), the Tenebrio molitor (Linn.), and various Neerophores \Necrophorus Fabr.) and Silphes {Silplia Fabr.). These larvie of the Coleoptera, which are at first developed in old manure of the dovecot, finish by attacking the young Pigeons, gnawing the skin of the neck and abdomen — even the superficial muscles — and producing wounds which are often fatal, and in which burrow the larvte of Muscidte. This evil is closely allied to the uncleanhness of habita- tions, and should be remedied. Otherwise, these vermin can be made to disappear by the means already indicated : but in this particular case the floor of the dovecot should be covered with pine sawdust mixed with sand, some of this mixture being also put in the The attention to individuals consists of removing the larvae from the surface of the wounds, and in dressing these with a solution of carbolic acid — 1 to 10. 1 Railliet. Sur une Punaisc qui attaque lea Pouhs. Bull, de la See. de Me'd. V^t^r. Pratique, 1890, p. 99. CHAPTER V. ACAKIASES.^ By the term Acarlasis (Kirby and Spence) is understood every disease caused by Acabina. These form a separate order in the class Arachnida. The Acarina — often designated Acaridce—^hich. were at one time named Acari, Mites, etc. — are generally creatures of small dimensions, with short, thick, non-articulated bodies, and having the head, thorax, and abdomen all in one mass. In some instances, however, the head and thorax are separated by a groove, and it may happen that the thorax is rendered distinct from the abdomen in the same way. The chitinous integument usually shows very fine parallel ridges, and in places varied enlargements with bristles, hairs, prickers, etc., that may be collectively designated trichomce (from Opi^, rptxos, hair). The anterior portion of the cephalo-thorax has a depression named the cavierostoma, because it lodges the buccal parts or rostrum, which is generally formed of distinct pieces arranged for biting or sucking, and comprising from above to below : a pair of chclicerce or mandibles, a pair of jaws or maxilla., each carrying on the sides a maxillary palp or loiuer lip. This rostrum projects beyond the camerostoma, or remains concealed beneath the epistoma — the upper wall of the camerostoma. The four pairs of legs — composed of six, five, or even three articles (or joints) only — have their base either inserted directly into the non-modified integument, or into its skeletal enlargements, which are designated epimercz. They are terminated by hairs or claws, and have often, besides, a kind of vesicular lobe, or membranous caruncle, which, by its power of adhesion, singularly facilitates the progress of the Insect. In the majority of the parasitic species, these ambulacra are consti- tuted by a small pediculated sucker. A large number of terrestrial or aquatic Acari have one or two pairs of stigmata — the external openings (tracheic) of the respiratory appara- tus — pierced in the tegumentary thickenings named pcritrevicB. The stigmata are absent in the majority of permanent parasitic forms, in which the respiration is simply cutaneous. The sexes are separate in all the Acarina. The males are much fewer than the females, and are distinguished from them by their smaller * M^gnin. Les Parasites et les Maladies Parasitaires, Paris, 1890 — P. Gervais. Histoire Natur. des Insectes. Apt&res, III., Paris, 1844 — Ziirn. Die Schmarotzer. r* Theil, Die Thierischen Parasiten, Weimar, 1882 — Railliet. Elements de Zoologie Mtdicale et Ayricole, Paris, 1886. ACAEIASES. 93 size, certain details in conformation, the presence of copulatory organs, etc. They also often lead a different kind of life, and have a different regime. Amongst the males and females in the colonies of Acarina, there are found a larger or smaller number of individuals vs^ho do not present definite sexual characters. These are the larva, which are usually provided with only three pairs of legs (hexapodal larvcs). They under- go a succession of metamorphoses, one of which leaves them with a fourth pair of legs, and the creature is then termed a nympha (or nymph or pupa). Another metamorphosis brings about the development of the genital organs, and the Acarus is now a pmhesccnt male or female (or imago). Finally, a last transformation, proper to the female and con- secutive to copulation, makes her an ovigcrous female. The majority of the Acarina are parasitic — either temporarily or per- manently. Among the first there are some which are merely com- mensal, the presence of which is not accompanied by any particular disturbance, and which only require a host as a means of transport. Others live on epidermic ddbris and natural excretions of the skin ; while others, again, prick the integument in order to suck the blood, or instal themselves in its superficial layers and determine cutaneous affections, which are sometimes very serious. The order of Acarina contains a very great number of forms, and has been divided into families, the arrangement of which varies according to authorities which describe them. We recognise ten, which we classify as follows : Non-ver miform \ Acarina Legs inserted di- rectly into the integu- ment, with- out epi- merse. Legs articulated on distinct epinierae. Legs with 5 articles Legs with 6 articles. With tracheae. provided with hook- lets didactylous or styli- form - - - - •^ Chelicerae. I With no tracheae (marine Acari) Natatorical legs (aquatic Acari) - - - - Chelicerse styliform ; palpi free, antenniform - - - - Ambula- tory Legs. Chelicerae styliform or in claws palpi free, ravisher - - Chelicerae didactylous ; palpi cylindrical or conical, and par tially adherent to the lips - Vermiform Acarina (Legs with 5 articles Legs with 3 articles Oribatidiv. Ixodidoi. Gamasida;. HalacaridcH. Hydrachnida: Bdlidix. Trombidiidce. SarcoptidcE. Phyioptidcu. Demodtr.id(r. Of these ten families, only five concern us : these are the Ixodidce, Gamasida, Trombidiida, Sarcoptidce, and Demodecidce. Each of these may have representatives on the domesticated Mammalia or Birds, with the exception of the Demodecidse, which, so far as is at present 94 TREATISE ON PARASITIC DISEASES. known, are only found on Mammals. The following are the principal characters of these five families : — 1. Ixodidae. — These are relatively voluminous Acarina, and are more or less flat when fasting, globular when replete. The rostrum (Figs. 53, 54) is composed of: 1, two elongated chelifers, terminating in a harpoon-like article with three or four teeth ; 2, an undivided maxillo- labial dart, formed by fusion of the two maxillaa along with the inferior lip and tongue, the dart being furnished beneath, and sometimes on its sides, with several longitudinal rows of teeth, the points being retrograde ; it has, laterally, two quadri-articulated cylindrical or flattened palpi, or they may be channelled on their inner surface, so as to form for the dart, when brought together, a bivalve sheath. The legs have six articles terminating in an ambulacrum, formed by a caruncle plaited like a fan, and having a pair of booklets. The respiration is tracheal, the apparatus terminating in a pair of stigmata situated behind the fourth pair of legs, [and protected by a discoid peritrem pierced like a sieve. Often there are two pairs of eyes. The opening of the sexual organs is situated between the haunches of the first pair of legs. The Insect is oviparous. 2. Gamasidse. — The integument is coriaceous, partially or wholly, and has two chitinous plastrons : a superior, dorsal, and an inferior, ventral, which give attachment to the legs. The rostrum is arranged for pricking or sucking : the chelifers are generally disposed as didac- tylous pincers, and are usually dissimilar in the two sexes ; the maxillae are fused into a perfect tube on the upper surface by the labruna, which is festooned ; the maxillary palpi are simple, free, antenna3-like, composed of five articles, and provided inwardly with galea or secondary palpi. The legs have six articles, terminating by two booklets and a trilobate membranous caruncle. There are two stigmata situated near the posterior legs, and protected by a very long tubular peritrem, lying along and above the haunches, and open- ing in front. There are no eyes. 3. Trombidiidae. — These are nearly always soft x\carina, more or less hairy, generally bright-coloured, their skeleton being composed of epimers. The rostrum is a conical sucker formed of a pair of hooked or styliform chelifers, rarely as didactylous pincers, contained in the tube constituted by the joined maxillas and the lower lip ; the palpi are more or less voluminous, and the second last article is frequently terminated by a booklet, the last being fixed either at its base or, more rarely, at the middle part or summit. The legs have five or six articles, usually terminating in two hooks, and often accompanied by a cirrus or a small caruncle. The respiration is tracheal. There are often two eyes (Figs. 56, 57, 58). 4. Sarcoptidae.^These are the smallest of the Acarina, their size being between -1 mm. and 1 mm. The body is soft, white or reddish, the integument being sustained by epimers. The rostrum is composed of two short didactylous chelifers, gliding on a middle piece, spoon- shaped, and formed by the junction of the two jaws with the lip and tongue ; the maxillary palpi have three cylindrical articles. The legs have five articles disposed in two groups of two pairs each — one near the rostrum, the other near the abdomen. The tarsi are terminated by one or more booklets, which are often accompanied by a cam- ACARIASES. 95 panulated sucker or a vesiculous caruncle. There is no respiratory apparatus, the respiration being cutaneous. There are no eyes. 5. Demodecidae. — These are very small, vermiform, glabrous Acarina, the skeleton of which has epimers for its base. Their bodies are dis- tinctly divided into cephalothorax and abdomen ; the latter being conical and elongated. The legs are short, and have three articles : haunch, thigh and tarsus. The Insect is oviparous. There is only one genus — the Deinodex (Owen). The numerous species of parasites of the domesticated animals which these five families of Acarina contain, are far from producing the same degree of disturbance on or in the skin they inhabit. There are some which are merely commensals, living on the epidermic scales, and the remains of hairs and feathers. Others prick the skin in order to suck the blood, but their action does not extend beyond the points they attack. And a certain number, by their multiplication, the multiplicity of their bites, by the venom they implant, by the galleries they excavate, and by the deep situation in which they locate them- selves, give rise to a disease which is generally grave — psora or scabies. It is necessary, therefore, to distinguish between non-psoric Acariase>i and psoric Acariascs. The latter are produced either by the Acarina forming a special tribe in the Sarcoptidae — the psoric Sarcoptidcn or Sarcuptina, or by the Demodex. The non-psoric Acariases are due to the Gamasidae, the Trombidiidas, the Ixodidae, and the non-psoric Sarcoptidte. On the other hand, it is advantageous for study to consider separately the acariases of domestic Mammalia and those of Birds. On these principles are established the following divisions, in which, under the term ' acariases,' are passed in review all the Acarina — patho- genic or non-pathogenic— which Hve on the domesticated animals.^ A. -ACARIASES OF THE DOMESTICATED MAMMALIA. Article I.— Non-psoric Acariases. These acariases will be studied here in the same order as the famihes which produce them : Ixodidae, Gamasidse, Trombidiidce, and Sarcoptidae. I. Ixodidae. — The Ixodidae (see p. 94) are temporary parasites which may attack all the terrestrial vertebrata, but there is no constant correspondence between the species of host and that of the parasite ; the female nearly always only shows a kind of specific preference, the larvifi, the nymphai and the males being often found on the most diverse animals, differing in orders, and even in classes. P. J. Beneden has included them in his group of ' free parasites in early age.' * It ha"* be°n considered advisable to study auricular acariases when treating of the parasites of the eeutory organs (Book VII.). 96 TREATISE ON PAEASITIC DISEASES. This family only comprises two genera : the Ixodes and the Argas, which have been needlessly constituted two tribes : the IxodhuB and the Argasina. The Ixodes (Latreille) have the rostrum terminal, i.e., inserted in a depression on the anterior surface of the cephalothorax ; it is articulated, consequently, to a shield of variable shape and colour, according to the species, being small in the female, and covering all the upper parts of the body in the male. The maxillary palpi are sometimes thick, in other cases flat, and are generally grooved on their inner surface. The Ixodes are popularly known as Ticks and Wood-mites. They have been recognised for a very long time, as Aristotle speaks of them as Kwopato-TT^s, from which Hermann has derived the generic name CynorhcesUs, signifying * the Dog tormentor.' For it is on Dogs — and particularly sporting Dogs — that these creatures are most frequently found, as they frequent woody places and go amongst underwood and low plants which the Ixodes prefer, and where they live in a vagabond condition. Ac- ™ * cording to Latreille, the Ixodes maintain themselves suspended to plants by their anterior legs, ready to fall upon any animals which pass within their reach. Fig. 53. — Rostrum of the Ixodes ricinus, seen from below ; magnified about fifty- diameters. — Delaf ond. m, chelifers ; p, maxillary palpi ; d, maxillo-labial dart. Fig. 54. — Transverse section of the Egyptian Ixode, magnified fifty diameters. c, chelifers enveloped in the sheath ; p, maxillary palpi ; d, maxillo-labial dart. Propagated more or less distant from their host, they thus attach themselves to him, either to be transported by him, as in the case of the larvae and the males ; to be nourished on the small quantity of pus produced at that point in the skin where their barbed rostrum is implanted, as happens with certain nymphte and also males ; or to feed upon blood only, as occurs with the fecundated females. In order to obtain this living nourishment, the Tick fastens itself firmly on the host with its legs, directs its rostrum perpendicularly towards the skin, and on the selected point thrusts in the terminal hooks of its chelifers. In proportion as these penetrate, the dart ACAEIASES. 97 follows, and the retrograde teeth on the under surface of this organ ensures the stability of the apparatus in the wound. In this way the dart is driven in as far as its base, while the maxillary palpi remain external, and are apphed to the skin' on each side of the wound. The adherence of the rostrum in the derma is so close, that by violent traction on the Insect there is risk of only obtaining its body, the buccal pieces being left in the wound. Otherwise, methodical removal of the parasite nearly always results in tearing away a small shred of skin fixed on the teeth of the dart, and held between the palpi. The aspiratory apparatus consists of a thin membrane, expanded like a bell around the rostrum and the salient borders of the buccal cavity. In gorging themselves with blood, the fecundated females acquire a considerable size — sometimes tenfold their original volame ; but some of this increase is also due to the development of the enormous quantity of eggs contained in the uterus, and which renders this intense alimen- tation necessary. When satiated, and having attained the size of an olive — and even of a nutmeg — the female withdraws her rostrum from the skin of the host, falls to the ground, and — concealed beneath some object — lays an immense number of eggs agglomerated in a mass, and with which she remains for some time in contact. Hatching lasts from fifteen to twenty days. The female Ixode, now empty and shrivelled, and even less than her primitive volume, soon dies. The hexapod larvae that issue from the eggs are very small. They sally out on every side, and are often observed in the fur of wild rodents ; they do not attach themselves by the rostrum, and they pre- serve their primary clear colour. They may live for months without nourishment, and it is probable that they effect their transformation into nymphai in the ground. The latter are distinguished from the larvai by their being somewhat larger, and by the presence of four pairs of legs and respiratory stigmata. They are also distinguished from the adults by the absence of sexual organs ; but they live like the latter, with the rostrum implanted in the skin of their host — pene- trating sometimes beneath it, and causing the formation of purulent tumours. Their size increases and their colour becomes darker. Finally, they leave their host for the ground, where they undergo the change which endows them with sexual organs. The males find the females either on the ground or on an animal that they had located themselves upon, before or after the arrival of their co-mates ; and they all prefer those parts of the body where the skin is fine, and which are inaccessible to the tongue, teeth, limbs, or tail of their host. The Ixodes are found in every country, and are discovered on the most diverse species of Vertebrata ; but the specific determination of the different forms is rendered difficult by the great confusion that prevails. There have often been mistaken for different species the male 7 98 TREATISE ON PARASITIC DISEASES. aud female of the same species, and the same species has received distinct specific names because individuals belonging to it were observed on different hosts. Mention will be made of only the most common species — at least in our climate, and with regard to which there is perfect agreement amongst authorities. Ixodes ricinus (Linn.). — This Insect is very often seen on sporting Dogs. It is the longest known species, and that of which Aristotle speaks. It is named the Common Tick or Dog Tick, and is remarkable for the dissimilarity existing between the two sexes, with regard to the rostrum. When fasting, the body of the female is oval, orange-coloured, not festooned on the posterior border, and measures 4 mm. long and 3 mm. broad. Eeplete and fecundated, it resembles a seed of the castor-oil plant, is of a leaden colour, and is 10 mm. to 11 mm. long, and 6 mm. to 7 mm. broad. The rostrum is short and square, the dart rectangular, and furnished inferiorly and on each side with two longitudinal rows of teeth — eight in each row ; the chelifers terminate in a three-toothed harpoon ; the palpi are wide and short, and in the form of a chopping- FiG. 55. — The Ixodes ricinus of the Dog, a fecundated female after feeding. — Railliet. A, Natural size. B, Knlaroed ventral surface. C, Enlarged dorsal surface. knife. The male is 2-65 mm. long and 1-50 mm. broad, and has the body always fiat, ovo-triangular, angular in front, rounded and non- festooned behind, entirely covered on its upper surface by a dull-brown shield ; it has no eyes. The rostrum — shorter than that of the female — has only a single row of five teeth on the dart ; the chelifers are terminated by a four-toothed harpoon ; the palpi are more squat than in the female. The nympha and larvic have the characters of the species, modified by the attributes of their age (Megnin). This Ixocle is more particularly found upon hunting Dogs, but it has also been discovered by Megnin on \Yallachian Sheep and Sardinian ACARIASES. 99 Oxen. Man himself is sometimes attacked by it. In the larval, and even in the nymphal state, it often inhabits the skin of small wild Mammals — such as the Mole, Dormouse, Squirrel, Hare, Eabbit, etc. It appears to be spread all over France and is found in the majority of European countries. The duration of its life extends, on the average, between the months of May and October. Towards the end of Sep- tember, few are observed which have not attained adult age ; and from the commencement of October they are rarely found, males or females, even at that age. Animals do not appear to notice the presence of these parasites ; the quantity of blood they extract is not sufficient to injure their health, and the wound they leave after they fall off heals quickly and spontaneously. Nevertheless, it is advisable to immediately remove all the Ticks from Dogs which have brought them in from hunting, as the fecundated female, falling on the floor of the kennel, there brings forth a population of parasites which may be very troublesome to get rid of. The Ticks may be removed by gentle, gradually-increasing traction, the pain caused to the Dog being insignificant. When the Tick has been too forcibly withdrawn, it is often ruptured, and the rostrum remains in the wound, but is eliminated therefrom in a few days by a process of suppuration. It is therefore the best plan to compel the parasite to drop off, by touching it with a drop of benzine, petroleum, or oil of turpentine. When the kennel is infested by Ticks, it may be freed from them by washing it with boiling water, which should be applied to every corner, and especially the ceiling, which these Insects prefer. Ixodes reduvius (De Geer). — The rostrum is similar in both sexes ; it is twice as long as it is wide, and the dart is lancet-shaped with a sharp point, and provided on each side with three rows of teeth, two rows of which are on the inferior surface — one of these being internal, smaller, and interrupted — and one on the side, with stronger and sharper teeth. The chelifers are terminated by a live-pronged harpoon; the palpi are like the blade of a razor. The scutellum is black, and the Insect has no eyes. The female is of the same dimensions as the Ixodes ricinus ; it is reddish - yellow in colour when fasting, lead- coloured when replete ; and it is not festooned behind. Its scutellum is oval, has a narrow white border in front, and studded with a few hairs. The male is 3 mm. long, and 2 mm. broad, with tlie body triangular, rounded behind where it is not festooned, and the entire upper surface is covered by the scutellum (Megnin). This Ixode is widely distributed in France, and more especially attacks Sheep and Cattle ; it is also at times frequent on Dogs, and does not absolutely spare Man. Megnin reports having often met with it on Cattle and Horses in Auvergne, and on Sheep in the North of France ; but he has never seen it on Cattle coming from Normandy, or from ths West or East of 7—2 100 TREATISE ON PARASITIC DISEASES. France. It is the females, of course, which live as parasites ; they prefer to attach themselves about the flanks, where the skin is thin and favourable for their implantation. Their punctures are of little importance, for Horses and Cattle do not appear to notice them. When the Insects have filled themselves, they fall to the ground, and all traces of their havin^^ been on the skin soon disappear. ' The nympha of this species,' says Megnin, ' sometimes attacks hunting Horses that pass over land covered with underwood and broom, and cause a more serious condition than the punctures of the adults do. This nympha, which is only 1 mm. to 2 mm. long, has singular habits ; it is not content with planting its beak in the skin ... it lodges itself entirely beneath the integument, and by its presence there soon pro- duces large pustules, which are really small boils, and are accom- panied by intense itching.' Megnin gives an instance of a Horse which had the extremities of all its limbs studded with pustules, and beneath the crusts on these were found the bloated parasites in ques- tion. The Horse was cured by their successive extraction. Megnin has found similar pustules on the ears of Dogs and Hares, which were due, doubtless, to the same species of Ixode that Trillibert obtained in a serous cyst of six months' duration, and which was situated at the end of a Dog's ear.^ The Ixodes reduvius does not appear to cause any particular incon- venience to the Sheep. It fixes itself on parts destitute of wool — such as inside the arms and on the flanks. Ixode of Duges (I- Dugcsi Gerv.). — The rostrum is short and alike in both sexes. The dart is somewhat spatuliform, has the end rounded, and is furnished with four rows of teeth on each side ; the chelifers are terminated by a four-pronged harpoon ; the palpi are shorter than the dart, are slightly valvular, and have four very distinct articles. The fecundated female, when fasting, is (3 mm. long and 2-5 broad ; the body is pale-red in colour, narrow behind, and not festooned. When distended, it is 14 mm. long, 8 mm. broad, and is of a dark leaden hue. Its scutellum is narrow, short, and pentagonal, the sides parallel, and posterior angle rounded; it is of a dark-brown, dull tint, roughened, and has an eye at each of the two external and posterior angles. The viale is 3-5 mm. long and 2-5 mm. broad, and is subtriaugular in shape, the angles and sides being rounded. The scutellum, which covers all the upper surface, is brown, smooth, and shining, festooned at the posterior border, and has an eye on each side, at the second pair of pads (^Megnin). This Ixode is common in the South of France, where Duges discovered it ; it is also found in Italy, Algeria, and Morocco. It attacks Cattle, Sheep, and Dogs. There is nothing particular in its action, and the smallness of its rostrum reduces to a minimum the wounds left when it falls off or is pulled away. We may consider as a variety of this species the Ixodes of Guade- 1 Kecueil de M<5d. V^t^rinaire, 1863, p. 607. ACARIASES. 101 loups, a specimen of which we owe to the goodness of Couzin, the veterinary surgeon at Moule. It is distinguished from the type — such as it has been described by Megnin- — by the total dimensions being less, the colour of the legs — the two first articles of which are brown, the others being brighter — by the tint of the female, which is uniformly a dark maroon, and the smallness of the scutellum, which scarcely measures 1 mm. The French fauna comprises also the Ixode of Fabricius (I. Fabric it And.), the Epauletted Ixode (I. scapnlatus Meg.), the Pincer Ixode (/. chelifcr Meg.), which may be found on the Dog, according to Megnin ; as well as the Great Shield Ixode (I. mcgathyreus Leach), and the Autumn Ixode {I. autumnal is Leach). The first two, and the Marbled Ixode {I. marmoratus Eisso), have been found on Sheep, and the /. scapulatus on Cattle of the South of France (Megnin), But there still prevail great doubts as to the reality of these species, which some have attempted to differentiate by their rostrum and scutellum. Their effects have not been distinguished from those of the preceding species. Nevertheless, serious losses have been reported among Lambs in Kent, by the debility resulting from Ixodes, which had multiplied in an extraordinary manner in 1869. The species was not well deter- mined.^ Ticks have also been reported as very frequent among Cattle in the South-west of France. They more particularly fix themselves at the summit of the head, behind the ears, and render the animal irritable ; so that it is often really difficult to put Oxen in the yoke. A Camel Ixode (I. camelinus G. Fischer) has been described, which has been found on Camels in the steppes of Asia. A very widespread species which infests Cattle in Northern Africa, and which is found on those brought into the European markets from that country, and particularly into the French markets, is the Egyptian Ixode (/. agyptius Linn., I. Savignyi P. Gerv.). The rostrum is alike in the two sexes, and is large, salient, cylin- drical, and distinctly truncated ; the dart is a little spatuliform, and has three rows of teeth on each side of its lower surface ; the chelifers are terminated by a three-pronged harpoon, and the palpi are as long as the dart, but have no valves. The scutellum is black, roughened, and polygonal. The articles of the legs are brown at their base and yellow at the other extremity. The fecundated female, when empty, is 9 mm. long and 7 mm. wide ; it is red in colour, nearly square in form, and the posterior border has eight sUghtly-marked festoons. Its scutellum is nearly one-third of its length, is sub-rhomboideal, and has two eyes — one at each of the lateral angles. The male is 8 mm. long and 4-5 mm. broad, and is irregularly oval, being wider at the posterior border, which is cut into eight deep festoons. The scutellum covers all the upper surface, with the exception of two lateral, narrow borders of a j'-ellowish-white colour, and has an eye on each side, at the second pair of legs (Megnin). Megnin has given the name of Algerian Ixode (I. olgcriensis) to a ^ The Veterinarian, June. 1869. 102 TREATISE ON TABASITIC DISEASES. form which is distinguished from the preceding chiefly by its smaller dimensions, by the quadri-dented harpoon of the mandibles, and by the uniformly brown colour of the articles of the legs. To us this appears to be merely a variety of the Egyptian Ixode, in the company of which ^legnin states he found it in very great numbers on Cattle from Africa. The Egyptian Ixode— the largest known species — is very common in Egypt, in Algeria, and in most parts of Africa. We believe it to bs related to an Ixode we received from Guadeloupe, through Couzin, where it is known as the Tique seiu^galaisc. It has been considered, in fact, as derived from Senegal, whence it must have been imported with Cattle into the countries in which it is now seen. It is stated to be a stranger in Martinique, which, notwithstanding its proximity to Guadeloupe, will doubtless remain exempt from it, as that island does not receive African Cattle. We have the opportunity of meeting with this Ixode in the abattoirs of France, on Algerian Oxen ; and Megnin even affirms that it will eventually become acclimatized in the South of France, in the neighbourhood of Marseilles, by the temporary sojourn of African Cattle in that town and its environs, before their departure for the different markets. He bases this assertion on what he has observed with regard to the Green Lizard of Provence, on which he found a male Ixode that he believes is an Egyptian one. It has been known for a long time that the male of this species often fixes itself upon reptiles — such as the Greek and Mauritanian Tortoise — and on Lizards. The Cattle that Megnin has seen carrying swarms of these Ixodes about tlieir flanks, and the other parts of the abdomen, did not appear to suffer, nor did they try to remove them ; they arrived at Paris in good condition. Nevertheless, in Africa the Algerian Ixodes are not always inoffensive, for Lucas relates having seen, in 1845, in the district of Calle, Algeria, Oxen die from exhaustion through the effects of the parasites, W'hich were incessantly renewed on the surface of their bodies. Each female, in fact, attaining in its full plenitude the size of a hazel nut, it can easily be understood how this great subtraction of blood, repeated so very many times, should operate prejudicially on nutrition, to say nothing of the irritation set up on the skin. And the same effects have been witnessed by Couzin on the Horses, Cattle, and Mules in Guadeloupe. In addition, the wounds resulting from the punctures of these Insects become ulcers under the influence of the climate. According to the opinion of Megnin, it is possible that this ulceration is primarily due to the custom of removing the Ticks by means of hot knives ; the rostrum remaining in the skin causes eliminating suppuration, which leads to obstinate sores. In Guadeloupe, the Ixodes of Senegal are supposed to play an impor- tant part in the development of a serious affection known there as /am/, ^ C. Couzin. Etiuh siir le Farcin de la Guadelou])e. Revue V^tt'iinaire, 1879, p. 401. ACAEIASES. 103 and which is witnessed in Horses, Cattle, and Mules ; the ulcerous wounds just referred to are the starting-point of the disease. Nocard has recently demonstrated that this ' farcy of the Ox ' is a malady of microbic origin ; and it can be conceived that the Ixodes may be the agents of inoculation of the micro-organism that determines such a disease. It may be mentioned that this ' farcy ' is not known at Martinique, where there are no Senegal Ticks. Duges' Ixode, which is also frequent in Guadeloupe, where it is named the ' Creole Tick,' is not implicated in this etiology of farcy, as its puncture does not leave any trace because of the rostrum being so slender. Various parts of Central and South America are much infested by numerous Ixodes belonging to different species, as, for instance, the /. ninericanua (Liinn.), of Surinam, Pennsylvania, etc. ; I. liuinca, of Surinam and Brazil; I. bovis (Kiley), of Texas; I. rotundatus (Koch), of South America, etc. These are popularly designated by such names as Ticks, Prickers, CTCtrapattcs, and Garapatos. But there can be no doubt that under these denominations are confounded Ixodes and Argas. Of six Ixodes we have received from Guatemala (sent by our colleague Soula), four belonged to one species and two to another ; the species are quite distinct, and yet they are often confounded and referred to by the name of the American Ixode (I. americanus Linn.), or the Nigna Ixode. These specimens were collected on the Horse. 'This animal, owing to its being reared on the prairie— /w ire ro — is frequently literally covered with these parasites. They are seen on all parts of its body, but they prefer those regions that the Horse cannot reach — as the sides of the neck and shoulders, and the inner surface of the thighs. Animals do not appear to suffer from their presence.' Kalm, cited by De Geer, relates having seen horses ' which had the under part of the belly and other regions of the body so covered with these Ticks that it was scarcely possible to introduce the point of a knife between them, and they were so deeply buried in the flesh of the animal that it finally succumbed.' Cattle, and even Man himself, are very frequently attacked by these parasites. The Ixode which fixes itself on Cattle in Texas has been named the Ixodes bovis. Megnin mentions, on the authority of J. Sale, that the inhabitants of Central America firmly believe that these Ixodes can be made to fall oft" spontaneously by giving the infested animal salt to eat. The most simple and efficacious means of getting rid of them is to remove them one by one by means of forceps, or, better still, to touch them with benzine, petroleum, tobacco-juice, etc. (What is called the ' scrub Tick ' in Australia, from its frequenting the shrubs on the immense plains of that country, appears, from all accounts, to be a most formidable Insect. Unfortunately, I can obtain no exact description of it, but the latest writer who refers to it is Dr. Bancroft, of Melbourne, a summary of whose paper appeared recently.! He says there are many kinds of Ticks which attach themselves to Man and the Dog, but it is from the ' scrub Tick ' alone that harm arises. The scrub Tick is flat, brown in colour, and about one-eighth of an inch in length and breadth. When distended, it is as large as a pea. The female Tick only, like the mosquito, appears to bite. Ticks attach 1 British JledicalJonnial, May 1(5, 1S91. 104 TREATISE ON PARASITIC DISEASES. themselves by their mouth organs, and never become buried under the skin, as some persons have imagined. The Tick is particularly active in summer, and is found under leaves, ready to drop on any moving object. The poison appears to be absent, or only in a minute quantity, when it first attaches itself. A solution made of eight Ticks and a few drops of water, when injected under the skin of a Dog, produced no eflect, but the same Dog afterwards succumbed to the bite of two Ticks. The Tick sucks blood from the animal to which it has attached itself, and it is presumed that some poison, probably of the nature of a ferment, passes from the Tick into the animal. Most Mammals are susceptible to the attacks of the scrub Tick ; even Horses have been killed by it. Human beings would succumb were the Ticks suffered to remain long enough on the skin ; but by reason of the irritation caused they are discovered a few hours after attaching them- selves, and are invariably removed. The Guinea-pig and Kangaroo- dogs seem to be insusceptible to the poison. Dogs that have recovered from tick-bite become tick-proof. The native Australian animals are tick-proof by heredity. Dogs influenced by tick-poison generally show signs of paralysis on the sixth day, and die about the seventh or eighth. The Tick takes about a fortnight before it is ready to bite again. Providing a Tick be removed from a Dog before the fourth day after attaching itself, no symptoms will arise. To make a Dog tick- proof, proceed in the following manner : Make a slight cut, not sufficient to bring blood, behind the ear of the Dog, and gently press the snout of the Tick into the wound, when it will, as a rule, bite and hold on. Two Ticks should be placed on the Dog ; after they have been on two days, remove them. Grease, turpentine, or kerosene smeared over them will kill them. Allow a week to elapse, and then place two others upon the Dog, and remove them after being on three days ; then allow another week to elapse, place two more Ticks upon the Dog, and remove them before the fifth day. After this the Dog will be tick-proof. Valuable dogs which live in a locality where Ticks abound should be carefully examined every two days.) Argas (Argas Latr.). — In the general form and habits, these Insects greatly resemble the Ixodes, from which they are distinguished by the following characters : The rostrum, instead of being terminal, occupies the inferior face of the cephalo thorax. The maxillary palpi are anteuniform — that is, formed of cylindrical, subequal articles, very movable on each other. The scutellum is altogether absent. Only one species is met with in France : this is the bordered Argas, which lives on Birds. In hot countries, such as in Asia, i\.frica and America, there are several species that attack Man and the domesticated animals. Laboulbene and Megnin^ have described two species of Argas found in Persia, and which are a scourge to travellers. One is the Persian Argas (A. j^crsicus Fischer), chiefly known by the name of the Miana Bug, by reason of the locality which it more particularly infests. The information relating to it does not allude to its action on the domesticated animals. ^ Laboulbfene et M^'gnin. Mem. sur les Argas de Perse. Journal de I'Anat. et de la Physiologie, 1882, p. 317. ACAEIASES. 105 The other species is the Argas of Tholozan (A. Tholozani Lab. et Meg.), the body of which is relatively narrow, its sides parallel, the anterior extremity terminating in a blunt point, the posterior round, and the skin very finely gauffered. The adult females measure 8 mm. to 10 mm. long, and 4 mm. to 5 mm. broad. In a state of repletion their colour is a deep violet. In Persia this species is reputed to be very dangerous to Man. It is named Kcne or Sheep Bug, which leads to the supposition that, besides the human species, it also attacks the domesticated animals, or at least the Sheep. There are no precise details as to the characters and habits of the African Argas. Those of America have often been confounded with the Ixodes, under the name of Garapattes. They are more especially prevalent in Central America. Those of Mexico have been particularly studied by Alfred Duges and by Megnin.i Two species attack Man and the domesticated animals : these are the Argas turicata and the Argas of Mignin. The Argas turicata (Duges), as it is thus popularly named in Mexico, has a sub -rectangular body, nearly square, the anterior border angular and obtuse ; it measures 5 mm. to 6 mm. long. The Turicatas infest the Pigs of Ganajuato, Mexico, fixing themselves on the inside of the forearm, and running somewhat rapidly. Their punctures sometimes cause very serious accidents to Man, and the Pig cannot always sustain them with impunity. ' It often happens,' says Duges, quoted by Megnin, ' that newly-purchased Pigs are put into pigsties where, owing to the carelessness of the owners, the Turicatas abound ; some of the Pigs die during the night, and others are found incapable of getting up ; if compelled to rise, they stagger and tumble about, and cannot maintain themselves. In the dead Pigs, the connective tissue is distended around each puncture with an ecchymotic effusion to an extent of 5 centimetres in diameter. I have never examined further to ascertain if there were any other disoi-ders. Fowls which feed on the Argas, if only for a day, die in about three days, after becoming dull and ceasing to eat.' Duges has given the name of Airjas Megn'mi to a species the body of which is lyriform, the wide end being anterior, slightly angular forward, rounded behind, the female measuring 5 mm. to 6 mm. long and 3 mm. to 3-5 mm. broad. This kind is, according to Duges, very abundant in the State of Ganajuato, and is seen on the Horse, Ass, and Ox, principally in the ears ; but it often fixes itself on other animals, and on Man in particular. Megnin supposes that the numerous Ixodidaj that infest animals in Mexico, and with which the Horses of the French military expedition to that country were so much afflicted, ought to be included with this species, which is, otherwise, more troublesome than the American Ixodes mentioned above, and with which it has been confounded under the designation of ' Garapattes.' II. Gamasidae (see p. 91).— Two of the genera of this family have species living as parasites on the domesticated animals. These are the Gamascs and the Dermanysscs. The Gamases (Gamasus Latr.) have the integument partially or wholly coriaceous; the mandibuh are cheliform, and are similar or but little different in the two sexes. The larvae are hexapodal. ^ Megnin. Les Argas du Mexique. Journal de I'Anat. et de la Physiologic, 1885, p. 460. lOG tkp:atisk ox pakasitic diseases. One species only merits mention here — the Gamasus pteroptoides (Megnin), so named because of its resemblance to the Gamasidue of the genus Pteroptus. It lives in complete and permanent colonies at the bottom of the fur of Field-mice, Moles, and Eabbits, as well as on some Bats. The whole rostrum is salient and uncovered ; the inferior plastron is very small in the two sexes, and united by a membraneous integument to the superior plastron, which covers all the dorsal surface. The legs are nearly altogether of the same size, and similar in the two sexes ; the booklets and caruncle which terminate them are very developed. The nymphic have a short peritreme. The body is squat, oval, and brown-coloured. The length of the female is -55 mm., and the male •45 mm., the width of both being -30 mm. This parasite subsists on the natural exudations of the skin of its host, and perhaps, also, on that which it produces by the bites of its mandibles ; but up to the present time it has not been observed to do any particular harm. It has only been mentioned expressly as related to the Rabbit. Turnbull has found in the ear of an Ox an Acarus that Lddy considered belonged to the genus Gamasus. It will be referred to when treating of the ' Parasites of the Ear.' The Dermanysses (Dermanyssus Duges) may be found on the domes- ticated Mammals— such as the Horse, Ox, Dog and Cat. But they are always accidental, and come from Fowls, which are their natural hosts. They will therefore be considered when dealing with the acariases of Birds. III. Trombidiidse (see p. 94). — This family is divided into numerous sub-families, only two of which interest us. These are the Tromhidiiuc and the Chcijlctuuv.^ The Trombidinye are TrombidiidcC with soft integuments, chelifers terminating in booklets, palpi composed of five articles, the fifth being club-shaped and articulated at the base of the fourth, which is pro- longed beyond the fifth by a sharp hook. The legs have six articles, each leg ending in two hooks and a hairy cirre. The Insect has two eyes. In this sub-family is found the genus Trombidion {Tn>inhi(Jiiu)i Latr.), of which a species — the Trombidium holosericeum (Linn.) — lives as a parasite during its larval condition. Like all the Trombidions, the latter has pedunculated eyes and a skin covered with bristly hairs. Specifically, it is recognised by its scarlet colour, its nearly square body — a little wider in front than ^ In the sub-f;imily of Tetranyddce is placed tlie Birho Colorado, of the Argentine Kepublic and Uruguay, which, according to G. Haller, is only a Tetranychus ( Tttrany- chus moltstis.sbnuH Weyenbergh). This small Acarus, which is of a red colour, lives on the infeiior surface of the leaves of Xanth'mm macrocarpum, in a web that it spins ; but from December to the end of February it throws itself on warm-blooded animals, Man himself not escaping its visitations. The Jiicho Colorado buries its rostrum in the skin, and causes insupportable itching. — A. Railliet. Elantnts lie Zoolotjie Mtdicale et Afjricole, p. lOOfl. ACARIASES. 107 behind, where the terminal border is notched on the middle line ; hairs and cyhndrical papillae cover the body : these are round or obtuse at the summit on the dorsal surface, bristly on the ventral surface and the legs. The length is 1-35 mm., and maximum breadth 1-8 mm. This is a very widespread species— especially in the centre and West of France — abounding from the end of spring on grass-lauds and sandy slopes, and in woods, but rarely in gardens. It is phytophagous, and is often designated— as well as the neighbouring species— the Bed Mite. According to Megnin — whose opinion, however, has been disputed — the larval hexapod of the Trombidimn holosericeum is the parasite long known as the Boiujet, Bed Flea, Harvest Bug, etc., and which the older naturalists described as a species by the name of Leptiis autumualis. The various designations given to it are significative of the period when it is most abundant. The female lays her eggs in July. The larvae are orbicular in shape and orange-red in colour, the body being sprinkled with short, sparse hairs ; they have the eyes and stigmata of the adult, and six long cylindrical legs, each with six articles. The insect attaches itself to any animal that comes in its way, implanting its mandibles in the skin. Its ab- domen gradually becomes distended, and assumes comparatively consid- erable dimensions ; it is then that it attracts attention, and is recognised by the various names given to it. It measures -40 mm. long and -25 mm. broad. The Harvest Bugs attack the small Mammalia by preference, such as Moles and Hares, which are sometimes literally covered with them ; and Man is often invaded by them in the autumn, the Insects creeping rapidly along the limbs and fixing themselves on any part of the body, especially those parts which are clothed. Their punctures are accom- panied by insupportable itching. Among the domesticated animals, sporting Dogs are most exposed to trombidian acariasis. The first mention of the existence of this para- site on the Dog is due to Defrance ; it has since been confirmed by Delafond, Mathieu, Megnin, Friedberger, and other authors.^ 1 Defrance. Cited by C. Dum^ril, Art. Lepte, Diet, des Sc. Natur., XXVI., 1823, p. 61. — Delafond et Bourgiiignon. Trailt Pratique tic. la P^ore, 1862, p. 211. — Megnin, Mathieu. Bull. Soc. Centr. de Mi^d. Vetednaire, October 11, 1886. —Friedberger, Archiv. f. wissensch. und prakt. Thierheilk., 1875, p. 133. (Fleming. Veterinary Journal, 1878, p. 809.) Fig. 56. — Tromhidium holonerktum, fe- male, seen on the dorsal surface ; magni- fied twenty diameters. --Kailliet. 108 TREATISE ON PARASITIC DISEASES. On returning from the field, Dogs often exhibit sjinptoms of great itching around the eyes and nose, and on the paws and belly. A close examination will discover the cause to be the Harvest Bugs, wandering or fixed by their rostrum either in the sudoriparous gland-ducts, or, according to Gruby, at the root of the hair. They are sometimes in groups of ten or a dozen around one hair. Cats which frequent gardens may be affected in the same way, Dela- fond states. Fig. o7. — Harvest Bug, or larva of the Trniiil)idiuin holosericeum, seen from the ventral surface ; magnified one hundred diameters. — Railliet. According to an observation of Moreau (of Saint-Benin d'Azy), and confirmed by Eailliet,i what is known in France as the rafle or feu d'herbe, and described by Chabert, Fromage de Feugre, Lafore, Cruzel, etc., is nothing more than a case of trombidian acariasis. This affec- tion, which appears towards the end of summer, has been ascribed by the older writers to feeding the cows on the grape-stalks or newly- gathered forage. It occupies the inner surface of the limbs, and extends beneath the belly and on the shoulders, neck, and head, and consists of an eruption of pustules or hard pimples, from which exudes a serous or purulent matter that dries into crusts, and finally disappears as dust. In this way the malady disappears of itself. On cows so affected, Moreau has found colonies of this Insect, forming small disseminated patches of one or two square centimetres in extent. On cavalry Horses returning from the manoeuvres after harvest, Blaise has observed an erythematous affection which did not extend above the 1 Railliet. Bull, de la Soc. Cent, de M^d. Vet^r., 1886, p. U98. ACAEIASES. 109 knees or hocks, and which had been mistaken for symbiotic scabies, but was due simply to the Harvest Bugs. Csokor and Eloiro have made a similar observation with regard to Poultry. Otherwise, this affection is not serious. To free animals from the parasites, some frictions with a cloth sprinkled wdth benzine, with benzinated glycerine, or with sulphur ointment, are sufficient. A very dilute solution of carbolic acid (1 or 2 per cent.) is a good preventive, and also a curative agent. Certain warm countries of America are infested by the Leptus of un- determined species, which torment Man and animals, and are named Tlalsahuatc in Mexico, Bete rouge in Guiana, the Antilles, and Hon- duras, Colorado in Cuba, Niaibi in New Granada, Mouqui at Para, etc. The sub-family of Cheyletinae contains the soft-skinned Trombidiidge, with styliform chelicera^, and the palpi composed of three articles, the second of which has one or two booklets that extend beyond the last article. The legs have five articles, usually terminating in two booklets and a cirre. They have no eyes. The Cheyletse {CJicjjIcttis Latr.) are recognised by their enormous maxillary palpi, the second article of which has a single, large, falci- form booklet extending beyond the last article. There is a vagabond species that may be accidentally met with on the bodies of animals ; this is the Cheyletus eruditus (Schrank), so named because it is sometimes found in old books, as well as among rags, mouldy forage, etc. Picaglia has attributed to it a dermatosis observed on a Horse, resembling that produced by the Dcnnanyssus (jalli)ice ; but this opinion rests only on the fact that hay with which the the Horse was fed contained numerous Cheyletes.^ The Cheyletus parasitivorax (Meg.) lives normally on the Eabbit. It is commensal, or, rather, a useful mutualist, if it is true, as Megnin affirms, that it pursues the soft parasites on its host, principally the Listrophorex. The body is an elongated hexagon in shape, and of a pale-yellow colour. The rostrum is large and pentagonal, and equal to a fourth or third of the size of the body, while the palpi are about one- third the volume of the rostrum. The anterior legs are shorter than the posterior. The female is -45 mm., and the male -32 mm. long. IV. Sarcoptidae (see p. 94). — The Acarina comprised in this vast family live in very diverse conditions, which are nearly fixed for each type, and to which their conformation is subordinate. Their division into five tribes or sub-families, as proposed by Megnin, is gener- ally adopted; these are: 1. Sarcoptiche detriticolcs or TyrocjhjphincB ; 2. S. gliricoles or Listroplwrince ; 3. S. cysticoles or Cytoditince ; 4. S. plumicoles or Analgesince ; 5. S. psorica or Sarcoptince. To these may be added a somewhat, as yet, limited tribe, the Sarcoptidce cpider- micoles. ^ L. Picaglia. Sopra vna particofare dermafosi del Cavallo. Atti della Soc. dei Xaturalisti di Modena. Rendiconti delle Adunanze. 3rd Series, II., 1884. no TKEATISE ON PARASITIC DISEASES. The last four of these tribes will not be alluded to here. The Sar- coptidceci/sticoles or Cytoditime, the Sarcoptidce jiluviicoles or Analgcsince, and the Sarcoptidce epidennicolcs, are exclusively peculiar to Bii'ds, the first living in the connective tissue and air-sacs ; the second among the feathers, being nour- ished by the greasy matters excreted by the skin ; the Sarcoptida? epidermicoles con- ceal themselves among the epidermic cells, the formation of which they expedite, and in this way constitute a transition to the psoroptic Sax'coptidae or Sarcoptinaj. The latter are the agents causing the psoroe or scabies, which will be dealt with in the following article, when treating of the psoric acariases of Birds. The Sarcoptidse detriticoles, or Tyroglyphinse, are Acarina which subsist on decomposing animal or vegetable matters. Trouessart and Megnin have provisionally attached them to the Sarcoptidce insccti- coles, which have been studied by Berlese, and which resemble that tribe more than any other. The Tyroglyphince are only exceptionally met with on the domesticated animals, and then as foreign bodies. They correspond to the following description : Body covered with a smooth, even, sometimes nodular integument, having silky, plumose, or palmate hairs. Legs alike, similar in each anterior and posterior group, and in the two sexes. The abdominal extremicy also rounded in the two sexes (Mt'gnin). Yui. 58. — Chfyhtus jmrasitivorax, ovigerous female, ventral surface ; magnified one hundred diameters. These characters, compared with those of the other Sarcoptidge, always permit the Tyroglyphinai to be eliminated as simply acci- dental errant insects when they are found on a domesticated animal. We shall, therefore, limit ourselves to an enumeration of the five genera in this tribe : Tjiroglyplms, Carpogbjphus, Gli/cipJiagii.s, Capopliagus, and Scrrator. It is probably the Glyciphagus cursor (Gerv.) that Hering discovered on a Horse's foot affected with ' canker ' ; the horse had recently died. He regarded it as special to the disease, and consequently designated it Sarcoptcs hippopodos. The Listrophorinse have been designated Sarcoptidce gliricolcs, for the reason that they have been considered as peculiar to Eodents ACARIASES. Ill (Glires); they are also found, however, on other Mammals, They live at the bottom of the fur, and cause not the slightest irritation, the greasy matter of the skin suf- ficing for their nourishment. They are divided into two genera — Ltstro- j)horus and Myocoptes — only the first of which will be noticed. The Listrophores {ListropJiorus Pagenst.) have the body ovoid, com- pressed laterally, a large cephalo- thoracic plastron, the lip trans- formed into a kind of elongated pincers adapted to seize the hair. The Diale is provided with two copulatory suckers, and its posterior extremity is more or less notched. The female has the vulva between two groups of legs, and the posterior extremity is not notched. Listrophorus gibbus (Pagenst.). — The cephalo-thoracic plastron is simply notched above. The posterior extremity of the male has a flat, bifid prolongation. The length of both sexes is about -50 mm. It abounds in the fur of wild and domesticated Eabbits and Hares, on which it is seen twenty-four to forty-eight hours after the death of its host. Listrophorus mustelae (Me- gnin.). — The cephalo-thoracic plas- tron is divided into two pieces, which are movable on each other. The posterior extremity of the body of Fi.;. Tyroiili/ph us loiKjior Fi;;. 60. — Listrophorn'< gibbu-s, male, of tli< Rabbit, ventral surface ; magnified on hundred diameters. Fig. 61. — Listrophorus ijibbus, female, of the Rabbit, seen in proBle ; magnified one hundred diameters. the male is simply notched. The length of the male is -40 mm. to -44 mm. ; of the female, -45 mm. to -54 mm. It lives among the hair of the muzzle and anterior part of the body of the Ferret and Pole-cat. 112 TREATISE ON PARASITIC DISEASES, Article II.— Psoric Acariases.^ Psoric acariases, scabies, or j^sone, are caused by Acarina belonging to the tribe of Sarcoptinae or Demodecidoe. Their common features are their gravity, their greater or less difficulty to cure, the multiplication of the parasites, and the more or less serious alterations in the skin. They differ by the zoological nature of the Acarina producing them, and by the location of these — the psoric Sarcoptiduc living at various depths in the epidermis, the Demodecidic locating themselves almost exclusively in the sebaceous follicles. It is advantageous to study separately the scabies due to the Sarcoptinae — sarcoptinitic scabies — and that caused by the Demodex — demodcctic scabies. 1. Sakcoptinitic Scabies. Sarcoptinitic scabies possess a high degree of interest, as they com- prise nearly all the itches or psoras of Man and animals. The scabies or j'sora was designated by the Greeks ipojpa (from i/w, I rub), and by the Eomans as scabies (from scabere, to scratch). It is known as scabbia, rogna, raspa, in Italy; sarna, rom, in Spain; itch, scald, yuch {mange), in England; [jale in France; and Krdtzc, Krdtzausschlag, in Germany. History. — The history of scabies in animals is closely allied to that of the same disease in Man. It was nevertheless in the former that it was first mentioned in the Bible (Lev. xxii. 22). Moses excluded mangy animals from being ol!'ered at sacrifices. Polybius speaks of an epidemic itch [limopsoron) which affected the whole of the people and horses of Cisalpine Gaul, and which Hannibal attributed to privations (' History,' Book III. 87). The Greeks, and particularly the Koman agriculturists, were aware of the contagiousness of scabies, and the disasters that turpis scabies produced in the flocks. The Eomans applied the word scabies to various affections of the skin, so that we cannot conclude from what they have written that they were really acquainted with the parasitic disease ; but what proves that there was no confusion in the mind of Celsus, at least, with regard to it, is that he extends to Sheep-scabies several of his remarks on contagion, and indicates the course and treat- n.ent of the malady. It is not until we arrive at the time of the Arab physicians that we find the first precise notions on itch, and learn that there was then an idea of its parasitic nature. Avenzoar (Ibn-Zohr), who lived in the twelfth century (1072 — 1161), makes the first mention of it, and indi- cates the existence of a disease caused by the presence of a little creature, popularly known as soab. He says : ' Oriuntur aliqui in ^ Chabert. Traits de la Gale et des Dartres des Anmianx, Paris, 1873. — Furstenberg, Die Krdtzmilben der Mennchen und Thiere, Leipzig, 1861. — Delafond et Bouryuignon. Trailt Pratique d'Entornoloijie et de Patholof/ie Comparees de la Pisore ou Oak, Paris, 1862.— S. Verheyen.— Art. (Jale, Nouv. Diet. Prat, de M^d., de Chir. et d'Hyg. V^t^r., VII. Paris, 1862. ACAEIASES. 113 corpora suh ciiti extcrius pcdicuU parvunculi qui, cum excoriatur cutis, exeunt animalia viva tarn parvuncula quod vix possunt videri.' Al- though the term pediculi is employed, there can be no doubt, from the mention of the seat of disease and the minuteness of the animal- culae, that he had seen the Sarcoptes. But he was content with alluding to the fact, and did not seek to realize its great importance ; for, like his contemporaries, he only saw in scabies the result of an alteration in the humours. According to Fiirstenberg, we find in the PJu/sica Sancti Hildigardis (A.D. 1200) — the writer of which was the abbess of a convent on the Euppertsberg, near Bingen^an indication of the remedies against the animalcule of the itch. This is named sureii — a term popularly in use, and which shows that a knowledge of the parasite of psora had become vulgarized in the North as well as in the South ; the denomination was retained until the end of the seventeenth century. After the time of Abenzoar, the notion as to the animalcule of itch was perpetuated in traditions, in teachings, and in publications, but with alternations of eclat and obscurity which allowed it to remain somewhat of a doubtful matter. A number of authorities of the thirteenth and following centuries speak of it. In Ambrose Pare (1664) is to be found this passage : ' The flesh-worms (cirons) are little animals concealed in the skin, in which they burrow, crawl, and gnaw bit by bit, causing a troublesome and scratching itchiness. . . . These flesh- worms should be extracted by means of pins and needles.' The year 1634 is an important date in this history, because of the appearance of the book of Thomas Moufet (Iiiscctorujii sou minitnoruiu animalium theatruin, London). For the first time, it clearly indicates the precise point where the sarcopt of human itch was to be found ; for he expressly mentions that it was not to be sought for in the vesicles, but at the side of them : ' Hoc Iwhitcr ohservandum, syrones istos noil in i2)sis jpustulis, sed prope Jiabitare.' About the same period, Hauptmann consecrated one of the first applications which had been made of the microscope — discovered in 1619 — to an examination of the acarus, though he only gave a very imperfect drawing of it (1657). A book on Horses (Pferdeschatz) appeared at Frankfort nearly at this time, and in it mention is made of the Acari as Mo'iben, which live among the hairs of the tail, mane, and forelock of the Horse ; but according to Gerlach, the writer mis- took epidermic scales for animalcula^. Wedel, in 1672, pointed out that acari were the cause of itch in the Cat. The attempts of Haupt- mann were subsequently repeated by other observers, and notably by Michael Ettmiiller, who published a more exact representation of the Insect. In 1687, Cosimo Bonomo, in a letter addressed to Eedi, gives a.. remarkably exact description of itch and the acari, after the inves- tigations he had personally made, in common with the pharmacist,, Diacinto Cestoni, of Livorna. He speaks of the form of the acari,. and even mentions that he saw one of these animalcuhe lay an egg at the moment when he placed it under the magnifying glass, so that he was able to make a drawing of it. Along with Cestoni, he arrived at the conclusion that the acarus is alone the cause of itch ; that the disease is not engendered by perverted humours ; that the con- tagiousness of the malady is perfectly explained by the passage of the creature from one person to another ; and that internal remedies are 8 114 TKEATISE ON PARASITIC DISEASES. useless in the cure of the disease, treatment being limited to external applications that would kill the parasite. These exact notions, however, did not penetrate the mass of medical men. But in 1734, Linnaeus recognised the insect of itch {Acarus humcnum subciitcntetis), though he committed the grave error of con- sidering it as belonging to the same species as the cheese-mite, of which he thought it was only a variety. The dissertation of Nyander, a pupil of LinnaBus {Exantliemata viva), which appeared in 1757, raised a hot discussion ; Nyander clearly proving that the acarus should be sought for in the furrows and not in the pustules ; while Avelin — another pupil of Liunajus — attributed the itch of the Sheep, as well as that of Man, to the presence of an acarus, w^hich he had perhaps not seen. So that the physicians remained divided between the humoral and the parasitic theories of psora. In 1763, Sauvages wrote {Nosologic) : 'The illustrious Linnaeus has observed an itch on Cattle, which lias much resemblance to leprosy in the thickness and hardness of its tubercles ; it was caused and main- tained by insects that w^ere found located in these tubercles.' In 1778, De Geer personally observed the Sarcopt, and gave the first exact figure of it, indicating, at the same time, the characters that serve to distinguish it from the cheese-mite. In 1786, a great observer — the Hanoverian physician, Wichmann — published an important memoir {^tiologic dcr Kriitzc), in which, by new facts, he magisterially and decisively established the parasitic doctrine of scabies almost as it is known to-day ; and in a second edition of his work (1791), he success- fully combated the objections raised against his views, with regard to metastases, repercussions, etc. He also published the hypothesis that the scabies of Sheep is likewise due to an acarus, and that the wool ]ilays an important part in its propagation. Abilgaard, professor at the Copenhagen Veterinary School, wrote to him in 1787, to the effect that the treatment justified his theory, as by the exclusive employment of local applications he had cured a large number of mangy animals. Unfortunately, Wichmann had left a loophole for the old prejudice in favour of psoric repercussions, as he admitted that these might be the possible consequence of the absorption of the excrementitial matters of the acarus ; so that doubts and denials persisted. Kersting, the first director of the Hanover Veterinary School, had plainly seen the animalculse on mangy Horses ; but he did not consider them the cause of the disease, as he could not succeed in producing it on a healthy Horse, by sprinkling the dust from the skin of an affected animal on it for fourteen consecutive days. It is true that in Germany, Viedebantt, who was entrusted with the task of studying itch in the Sheep — the disease was then prevailing in a disastrous manner among flocks — attributed it, in 1790, to insects which were in the air and on the pastures, and succeeded in trans- mitting the affection from one Sheep to another. But this assertion is accompanied by so many errors on all points, that it is very evident that Viedebantt had not seen that of which he spoke, and that his statement is nothing more than a hasty and chance generalization with regard to what Wichmann had so well established, in reference to the itch of Man. To Walz belongs the honour of the real discovery of the Sheep acarus in 1809. Soon after (1812), Gohier collected the parasites on mangy Horses, and Saint-Didier gave an illustrated description of them. ACARIASES. 115 Gohier mentions Dorfeuille, sen., as the veterinary surgeon who, in 1813, discovered the acarus of the Ox ; and he himself observed it during the following year on Hungarian cattle which had accompanied the Austrian army to Lyons. He adds that, by means of a magnifying- glass, he had seen the acarus of the Sheep, Dog, and Rabbit. Notwithstanding the observations of Wichmann, Walz, Gohier, and numerous naturalists, the existence and action of the psoric acarus were generally unknown or disregarded in medicine ; for, forgetful of the past recommendations, it was sought for in the vesicle, but could not be found, and therefore the conclusion was arrived at that it did not exist. Discussions on the opinions of the Ancients with regard to the animalcule continued until 1812, when Gales, pharmacist to the Saint- Louis Hospital at Paris, published a dissertation on the itch, and announced that he had constantly found in the 'pustules the creature so much sought after, and of which he gave a sketch. This work attracted considerable attention, and according to Alibert, Gales ap- peared to have established the reign of the Sarcopt. But nobody else could discover the mysterious flesh-worm, and it was still sought for in the vesicles, on the indications of Pinel, who had assigned it that loca- tion. During more than fifteen years, the figure published by Gales was reproduced in every book on the subject, as an exact representa- tion of the itch parasite. He had communicated the disease to himself by the transfer of an acarus, and he had experimentally transmitted it to children. Nevertheless, it was asserted that his pretended discovery was a gross error, if not an imposture. Easpail, who, like so many others, acting on the directions of Gales, had unsuccessfully attempted to find the parasite in the vesicles, in 1829 demonstrated that the animalcule represented by Gales was only the checsc-mite. After these unfortunate attempts, incredulity resumed its sway, and was extended even to the writing of the older observers. The inscrut- able animalcule was all but renounced when, in 1834, a Corsican — Francis Renucci, studying medicine at Paris — hearing the existence of the acarus denied at the Saint-Louis Hospital, proposed to show it forthwith; he imitated the procedure of the poor women in his country, in extirpating the Sarcopt at the point of a needle carried to the ex- tremity of the irregular furrow leaving each vesicle. Prom that moment the nature of scabies was definitely recognised, and the correctness of the observations of Moufet, Nyander, Wichmann, and so many other previous observers, was fully acknowledged. The most recent investigations have had for their principal object the anatomy and physiology of the acarus, as well as the scientific treat- ment of scabies based on the teachings of natural history. The excel- lent thesis of Renucci (1835) is evidence of this ; also the work of Albin Gras (1831), who, from a therapeutical point of view, studied the action of certain agents on the Sarcopt ; that of Aube (1836), in which the l)arasite is represented as a noctambulous creature ; and the memoirs of Raspail, Eichstedt, Lanquetin, Robin, etc. With regard to scabies in animals, we have already mentioned the first allusion made to the acarus of the Cat by Wedel in 1672, then to its real discovery on the Sheep and Fox by Walz in 1809, and on the Horse, Ox, Dog, and Rabbit by Gohier in 1812 and 1814. It should also be mentioned that, at the commencement of this century, Have- Tuann, quoted by Ziirn, knew the itch acarus of the Horse, and gave a passable drawing of it. Tbe itch parasite of the Pig and Wild Boar 8—2 116 TREATISE ON TAKASITIC DISEASES. was found by Spinola in 1846. But our knowledge of the various species of Acarina of scabies has been more especially extended by the classical works of Gurlt and Hei'twig {Verglciclicude Untcrsncliiingcn iihcr die Hatit (les McnscJien uiid iibcr Krdtz iind liiiudemilhcn, Berlin, 1844), of Gerlach {Krdtze nnd Rciude, Berhn, 1857), of Fiirstenberg {Die Krdtz- milben dcr Menschen nnd Thieve, Leipzig, 1861), of Ch. Eobiu {Mcinoires aur diverscs espcccs d'Acaricns de la famille des Sarcoptidcs, Moscow, 1869), and of Delafondand Bourguignon [Traitc pratique d'entomologic ct de 2)atJiologie comparees de la psore, Paris, 1862). The name of Megnin should also be honourably associated with these, because of the numer- ous memoirs he has contributed on the various groups of Acarina, and especially those of psora. General Characters of the Psoric Sarcoptidse.— The body of these is oval or orbicular, obtuse at both ends, convex above, flat below, marked by fine, symmetrical, and sinuous streaks, except at those parts where there are the thickenings named plastrons. It has, besides, at dif- ferent points, trichomic — pricking bristles or hairs. There is a conical, mobile rostrum in front ; the maxillo-labial spoon, situated at the inferior surface, com- prises two lateral pieces or maxillaB joined to a posterior middle piece or chin, and is united, in the opening of the angle thus formed, by a thin membrane or lip. The floor of the mouth is constituted by the lan- guette, a single lancet-shaped piece. The cheliceric are placed longitudi- nally on the upper surface of the lip and languette, but does not adhere to them ; they are flat on their inner surface, by which they come into con- tact, and so limit the supero-lateral walls of the mouth, which is a prismatic cavity with three surfaces. J'jRch of them is formed of two articles, one of which, the shortest, is articulated on the other, which is the entire length of the organ ; from this results a kind of pincer, with dentated branches. The maxillary palpi are cylindrical or conical, and situated on nearly the same plane as the chelicera3 ; they curve round these, their convexity being external ; of their three articles, the basilar, which is very large, articulates wdth the corresponding maxilla, or with the latter and the chin. Finally, outside the palpi there are sometimes transparent, cariniform, mem- branous expansions which Ch. Kobin terms checks, and which, leaving the margin of the anterior part of the cephaloihorax (cavierostoma), are applied to the palpi, the curvature of which they follow. The legs have lor base the epimcrce, skeletal pieces that strengthen the integument. Each of the five articles (or joints) composing them — and which are, passing from the base to the distal extremity, the Fii;. t)2.— Kostiuiii iind let; ol ir of the Sarcojit'-a .scabic-i, magnified 300 diameters. — Kailliet. r, cheliceriE or mandibiili ; mx, max illifi ; la, languette ; li, lower lip ; / cheeks ; 2', maxillary palpi ; .s, sttrninii 1, 2, 3, 4, f), articles (or joints) of tli( le" : a, .sucker ambulacrum. ACARIASES. 117 haunch {coxa), trochanter, thi(ih [or femora), sJiaiik (or tibia), and tarsus — comprises a solid piece and varied appendages, hairs, or bristles. The tarsus is terminated by a long bristle, or by an ambulacrum composed of a transparent pedicle of one or three pieces, and a campanulated ex- pansion or ambulacrous sucker, which ensures adhesion to the smoothest surfaces. The digestive apparatus, with rare exceptions, is only observable at its two orifices. The anus is a longitudinal, median slit, usually situated at the posterior border, but sometimes on the upper surface, and only at a tangent to the posterior border. Fig. 63. — Psoroptts communU, var. e(iui : adult male and female, coupled ; seen from the dorsal surface ; magnified one hundred diameters. — Delafond. The sexes are distinguished by peculiarities in the legs and the general shape of the body, by details in the organization of the external parts of the genital apparatus, and by the size — the male being always smaller than the female. The male organ is situated between the two last legs, on the middle line. It comprises a small number of strong chitinous pieces that form a complex genital armour, and which protects or directs the penis. Behind this ai-rangement there are often two circular suckers, placed sym- 118 TREATISE ON PARASITIC DISEASES. metrically on each side of the middle line, and which serve to fix the male to the female. The posterior border, in regard to these two copu- latory suckers, has usually two prolongations or lobes furnished with several bristles, which may have a share in copulation. In the female the anus serves also as vulva ; and for this purpose, at a certain period, it assumes large dimensions, being then designated the ndvo-anal slit. "When the young female has become fecundated, and is therefore an origcrous female, this orifice becomes of a greater size, and is a special organ for ovulation. This ovulating vulva (the tucostoma of Railliet) is seen on the inferior surface of the cephalothorax, at or behind the second pair of legs, appearing as a transverse slit with wrinkled lips, and sometimes provided with accessory chitinous pieces. The psoric Sarcoptidte attack the epidermis of the animals upon which they live, and their punctures are followed by the formation of more or less thick crusts, probably because they deposit a venomous saliva in the small wounds. They are oviparous, sometimes ovoviviparous. The eggs are ovoid, their contents granular, and the shell transparent. When they are ad- vanced in hatching, the embryo can be distinguished with its three pairs of well-developed legs bent beneath the body, and converging towards the centre, the hairs lying along them. Incubation'only lasts foi- a few days, as has been ascertained by Eich- stedt, Bourguiguon and Delafond, Gerlach and Burchart, Gudden and Piirsteuberg. Bourguignon, like Eichstedt, fixes the period at ten days, he having seen the eggs of the Sarcoptes scahiel which had been kept in a small stove at the temperature of the body, hatched in about that time. Fiirstenberg states that the period is from six to seven days. Gerlach has hatched them in about three days ; after assuring himself of the limpidity of the contents of the eggs, he placed them between two glass plates which he carried upon himself day and night, from time to time allowing a drop of water or saliva to pass between the plates. Burchart, who experimented at the same time, placed the glass plates in a pocket in his underclothing, which he left off at night ; the eggs were two days later in being hatched, or five days' incubation (S. Verheyen). These different results are conformable with the varied physiognomies the course of scabies may assume. The disease seems to sleep in winter, to waken up into activity on the return of warm weather. It is therefore established that the duration of incubation varies according to more or less favourable conditions, dependent upon the season, the activity of the local circulation of the mangy animal, the thickness of its coat, etc. Considering the rapidity with which the disease is developed in certain cases, Megnin is inclined to diminish this duration; and he estimates that when all the conditions are favourable, from twenty-four to forty-eight hours may suffice for incuba- tion. The duration of the germinative faculty of the eggs— the maximum ACAEIASES. 119 time about which, when removed from the body of the host, they can yet give origin to the embryos — has not been determined. Gerlach has, however, seen the eggs of the Sarcopt of the Horse hatch after four weeks. It is certainly an interesting question to solve, as it is the one upon which the duration of activity of the contagion of scabies depends. When the larva) issue from the eggs, they undergo those meta- morphoses which have been more especially made known by the researches of Delafond and Bourguignon, and Fiirstenberg and Megnin. 1st Age. Larva. — The small acarus just hatched differs chiefly from the adult of the same species, by the absence of the fourth pair of legs and the genital organs, and by its smaller size. At the back part of the abdomen is a pair of more or less long bristles. In this state it is named a larca (De Geer), and before passing to the second age it has to submit to two or three moultings, in order to allow it to grow. At each of these crises it becomes inert, and all its parts are reduced to a cellular mass, at the expense of which the organs are formed anew — the change taking place within the integument, this playing the part of a shell ; according to the expression of Claparede, the animal again becomes an ovum. 2nd Age. Nympha. — The last moulting of the larva brings it to the second age — that of nyinpha (Duges). It is characterized by the presence of the fourth pair of legs, which are a little smaller and are less complete than those of the female, which the nympha most resembles. There are as yet no sexaal organs. With the nymphge there is not so much variation in size as is the case with the larvae, proving that there is little or no moulting during this age, which is otherwise very brief. It may be remarked, however, that there are two different sizes among the nymphae, but both in moulting are arrived at puberty, the smallest being the males, the largest the females (Megnin). 3rcZ Age. Male and Female at Puberty. — The metamorphosis of the nympha? brings the Sarcoptida) to the age of coupling ; it is the last for the males, which are now recognised by their sexual characteristics, the females having only the vulvo - anal slit and are named pubescent females. The pubescent male and female have the various parts of the integument more accentuated and deeper coloured than in the preceding states. Copulation is accomplished in varied conditions. The termina- tion of existence in the male is principally devoted to the accomplish- ment of that act ; but the female undergoes another moulting and then arrives at the fourth age. AtJi Age. Ocigerous Female. — This fourth age — the egg-laying age — is recognisable by the presence of the sub-thoracic vulva, and the ovigerous female, as she is now termed, also undergoes modifications in the third and fourth pair of legs, or in the latter only, varying according to the genera. In the abdomen — the walls of which are transparent — can often be perceived one or more eggs, which will be extruded accord- ing to circumstances connected with the habitat and genera of the creatures. ' Judging from the number of ova Gerlach found in a gallery of the 120 TREATISE ON PARASITIC DISEASES. Sarcopt, he certainly did not exaggerate in attributing to each female an average production of fifteen individuals — five of them males and ten females. The generative faculty being reached when fifteen days old, he fixed a progressive rate of increase which had uo pretension to Fig. 6i. —Si/rn/notes aaricalarum: a pubescent female beiiij;; trans formed into an ovi- gerous female during copulation ; magnified one hundred diameters. The male has been slightly separated by compression of the preparation. — Railliet. mathematical exactitude, but which gives an idea of the multiplication of these parasites, and the rapidity with which scabies is propagated among agglomerations of Men or animals. 1st generation after 1 5 days 10 females 5 males. 2nd 30 „ 100 „ 50 „ 3rd 45 „ 1,000 „ 500 „ 4th 60 „ 10,000 „ 5,000 „ 5th 75 „ 100,000 ,, 50,000 „ 6th 90 „ 1,000,000 ,, 500,000 „ So that from two individuals, male and female, there are one million five hundred thousand descendants in about three months. The'production of an animal species is on a par with its chances of destruction ; when animals affected with scabies are left to themselves, these chances are fewer than is the case with many other invertebrates, and if we might judge from the extent of the crusts and the number of auimalculae necessary to cause the formation of these and to maintain them, the enormous multiplication established by this computation does not appear to bo exaggerated ' (S. Verheyen). ACAEIASES. 121 The habits of psoric Sarcoptidse vary with their genera and species. All the Acarina are divided into three very distinct genera : Sarcoptes, Psoroptes, and Symbiotes. The Sarcoptes (Latr.) {a-dp^, flesh ; KoirTea', to cut) are recognised by their rounded or slightly oval body ; short rostrum, margined by two cheeks; short, thick, conical legs, the two posterior being quite or nearly concealed beneath the abdominal surface ; the tarsus has often an ambulacrous sucker, in the form of a simple and somewhat long pedicle ; the male is usuahy destitute of copulatory suckers, and never has abdominal lobes. The Psoroptes {Psoroptes P. Gerv., Dermatodectcs Gerlach, Dermato- koptes Fiirst.) {^(.opa, psora; Trrvlo-creiv, to conceal) have the body oval; rostrum conical, elongated, and destitute of cheeks ; the legs are thick, especially the anterior ones, and are all visible outside the lateral margins of the body ; the ambulatory suckers are carried on a long tri- articulated pedicle ; the male has copulatory suckers and abdominal prolongations. The Symbiotes^ {Symbiotes Gerlach, Chorioptcs P. Gerv., Dermato- pharjiLS Fiirst., Sarco-dermatodectcs Del. and Bourg.) (o-r i/, with ; f^los, life) have an oval body ; rostrum slightly conical, as wide as it is long, and destitute of cheeks ; the legs long, thick, and visible beyond the sides of the body ; the ambulatory suckers are very wide and carried at the end of a simple and short pedicle ; the male has copulatory suckers, and more or less developed abdominal prolongations. Sarcoptes. — The genus Sarcopt comprises a small number of species forming two sections^ or sub-genera — Exisarcoptcs Eailliet, proper to the Mammalia, and Kncmidokoptes Fiirstenberg {Dermatoryctes Ehlers), special to Birds. The Sarcoptes properly so called, or Eusarcoptes, have the body orbicular or ovoid, provided with squamiform prominences, and spinules on the notoga strum. The males have no ambulatory suckers on the third pair of legs, and never have any copulatory suckers. The pubes- cent and ovigerous females have on the first two pairs of legs ambu- latory suckers, and on the other two pairs only hairs. They are oviparous. This section comprises two spscies — the Sarcopt of scabies and the dwarf Sarcopt. The Sarcopt of scabies (.S. scabiei De Geer, S. communis Del. and Bourg.) has the body slightly oval, marked by parallel ridges, which are interrupted on the dorsal surface, as far as the sides, by acute conical projections. This surface has, besides, two long needles or spinules on the border of the epistoma ; three short and thick spinules, ' The name cf Choriopted, created by P. Gervais in 1859 for an acanis of this genus found by Delafond on the Goat, cannot; be .'!ul)stituted for that of Symbiotes introduced by Gerlach (Krdtte unci Bamie, Berlin, 1857), the latter name having only been em- I'loyed at a later j>eri' d by Redtenbacher to designate a genus of Coleopterse of the family of Cryptcphagidae (Fauna Austrica, Die Kiiftr. 2te Auflage, Vienna, 1858, p. 371). - Railliet. Art. Parasiiex. Nouv. Diction. Prat, de Med., de Chir. et d'Hyg. Vet^rinaires, XV., 1888, p. 484. 122 TKEATISE ON PARASITIC DISEASES. in triangle, on each side, behind the origin of the second pair of legs ; seven spinules disposed in four rows — two on each side of the middle line — on the posterior quarter of the body ; and a chitiuous, grained plastron on the cephalothorax, in front of the groups of three spinules. There are two long bristles on each side of the anus, which is retro- dorsal. The first two pairs of legs are provided with ambulatory suckers ; the fourth pair have them in the male. In the latter the third pair, and in the female the third and fourth pair of legs, carry a long bristle, instead of an ambulatory sucker. The Sarcoptes scabici live on Man and a large number of Mammals, and by their presence cause the development of ordinary itch or mange. Fig. 65.—Sarcojitt>> scahiti, var. erpii: ovi gerous female, seen on the dorsal sui face; magnified one hundred diameter.-^ Fig. 66. — Sarcoptenscahitl, VAi: er/ni : ovi- gerous ffinale, seen on the ventral surface ; magnified one hundred diameters. One peculiarity in their habits consists in the female depositing her eggs at the bottom of furrows or sub-epidermic galleries, a circumstance that renders the cure of scabies somewhat difficult. The Sarcoptes scabici varies in its dimensions and in secondary anatomical details, according to the species of Mammal it lives upon ; hence it happens that there are somewhat numerous varieties, which many authorities have described as so many species. According to Megnin, it is more particularly the dimensions that may serve to characterize varieties ; and these dimensions ' are closely related to the thickness of the skin of the animal which affords them a habitat. So it is that the Pachydermata maintain the largest variety ; then come the Carnivora, next the Euminants, the Eodents, etc' These varieties— which we distinguish after the name of their host — are nine in number, ACABIASBS. 123 and may be classed in the order of their decreasing dimensions : sids, equi, vulpis, lupi, caprce, cameli, ovis, hydrochoeri, hominis. We will only notice here those which live on the domesticated animals. The Sarcopt of the Horse {S. scahici, var. equi; S. equi Gerlach) has the body of an elongated oval shape, measuring -43 mm. to -47 mm. in length in the ovigerous female, and -25 mm. to -28 mm. in the male ; the breadth being in the former from -32 mm. to -35 mm., and in the latter -18 mm. to -20 mm. It lives on Solipeds. The Sarcopt of the Sheep (S. scabiei, var. ovis; S. squamiferus ovis Gerl.) has the six anterior spinules on the back short, in the form of an acorn ; the fourteen posterior spinules are longer and fusiform. In the Sheep it causes scabies of the head. Megnin has also found it on Moufflons and Gazelles. The length of the ovigerous female is -35 mm. to -49 mm., of the male -22 mm. to -25 mm. ; the v/idth of the former is -20 mm. to -36 mm., and of the latter •^C> u\m. to -19 mm. Fig . b 7. — Sarcop tc>i scahie i, var. equi : hexapod larva, seen on the ventral sur- face ; magnified one hun- dred diameters. Fig. 68. — Sarcoptes scabiei, var. equi: octopod nympha, seen on the vential surface; magnified one hundred dia- meters. Fig. 69. — Sarcoptes sca- biei, VAT. equi : male, seen on the ventral surface ; magnified one hundred diameters. The Sarcopt of the Goat (S. scabiei, var. caprce; S. caprce Eoloff) is identical with the preceding, and its dimensions are nearly the same. The length of the ovigerous female is -35 mm. to -44 mm., of the male •21 mm. to -25 mm. ; the width of the former being from -27 mm. to •34 mm., and of the latter ^17 mm. to ^22 mm. The Sarcopt of the Pig (S. scabiei, var. suis; S. squamiferus Filrst.) resembles the preceding two. The ovigerous female measures ^40 mm. to •SO mm. long, and the male ^25 mm. to ^35 mm., the former being •32 mm. to ^39 mm. wide, and the latter -19 mm. to ^30 mm. This variety has also been observed on the Dog. Another variety found on the Pig by Guzzoni is much smaller in size, the female being ^29 mm. long, and ^21 mm. broad ; the male ^17 mm. long, and -13 mm. broad. The Sarcopt of the Wolf (5^. scabiei, yav. lupi ; S. sc. crustosce, Fiirst.) has been found by Megnin on Wolves affected with mange, and he has identified it with that which, according to Fiirstenberg, causes in Man the crusty form of scabies known as the Norivegian itch — the country in which it most frequently appears — and that form of mange which affects Deer kept in menageries. Eailliet and Cadiot have also seen this parasite on a Dog affected with crusted mange. 124 TREATISE ON PAKASITIC DISEASES, The Sarcopt of the Camel (S. scabici, var. cameli) has the integu- mentary markings less marked than they are in the other varieties. The length of the ovigerous female is -44 mm., and that of the male •24 mm., while the former is "oS mm. broad, and the latter -16 mm. (?). It causes the mange of the Camel, Llama (P. Gervais), Giraffe (Megnin), and the Bubalis Antelope (Railliet). The Sarcopt of the Dog (.S. scabiei, var. ca7iis) has been found on several occasions by Eailliet and Cadiot, as well as by ourselves, on mangy dogs. It is distinct from the varieties snis and liqyi, which are also sometimes met with on the Dog. Its dimensions are slightly greater than the following, which are those of the Sarcopt of Man {S. scabici, YSir. ]io»iinis): Length of ovigerous female -30 mm., male •20 mm. ; breadth of former ^26 mm., of latter -16 mm. Sarcoptes of exactly these dimensions have been seen on the Dog by Delafond and Megnin. The Sarcopt of the Capyb.ara (S. scabici, var. hydrochceri), which Megnin allies with that of the Ferret, has nearly the same dimensions Fig. 70. — Sarcoptes minor, var. cati : an Fig. 71. — Sarcoptea minor, var. cati : an ovigerous female, seen from below; mag- ovigerous female, seen from above; nified one hundred diameters. magnified one hundred diameters. as that of the Dog. The ovigerous female measures -36 mm. long, and the male ^22 mm., while the breadth of the former is •SO mm., and that of the male •IG mm. It causes the sarcoptic mange of the Ferret. The diverse varieties of Sarcoptes are not localized on a determinate species of Mammalia, for several may pass from one to the other, as will be shown hereafter when studying the scabies they give rise to. The second kind of Sarcopt found on Mammals, is the Dwarf Sarcopt {S. ?uf nor Fiirst. ; S. cati Hering ; the notcedra Sarcopt of Delafond and Bourguignon). The body is spherical ; the dorsal folds of the integument are disposed in a circular manner, become confounded with each other, form large blunt ridges, and encircle the anus, which is dorsal, near the posterior border in the male, in the posterior quarter in the female.^ There are two hairs longer than the rostrum on the epistoma, instead of the prickles. The six anterior spinules are arranged in a curved transverse ^ Hence the name of Sarcoptes notaidra (jnoTor, back ; tcpa, anus) given to this species by Delafond and Bourguignon. ACAEIASES. 125 I'ow, the convexity being forward. There are twelve spinules instead of fourteen, eight being arranged symmetrically in a transverse curved line, parallel to the preceding, in proximity to the anus, and four in two pairs near the borders of the anal slit. There is a pair of short anal bristles. The arrangement of the ambulatory suckers is the same as in the Sarcoptes scabiei. The dwarf Sarcopt lives on the head of the Suvmulot, Eabbit, Cat, and Coati. It is very variable in dimensions ; that found in mange of the Cat and Eabbit (var. cati or cuniculi) is, for the ovigerous female, '16 mm. to "25 mm. long, j^kj, 'i-i.—Sarcopiea mi- and for the male -12 mm. to -18 mm., the width nor, var ca<*.- male, seen from below ; magnined being for the former -13 mm. to "20 mm., and one hundred diameters, for the latter -09 mm. to '14: mm. That of the Surmulots (var. muris), also found by Colin on the Coati, is nearly double the size. According to Megnin, the fecundated female does Tk;. lo. — Psoroptes communis, var. equi : male, seen on the ventral surface ; magnified one hundred diameters. not burrow in a linear channel, but excavates for itself a veritable sub-epidermic nest. 126 TREATISE ON PARASITIC DISEASES. Psoroptes.— The genus Psoropt only contains a single species — the Psoroptes communis (Fiirst. ; Psoroptes longirostris Meg.). It is recognised by the characters already described for the genus (p. 121). In addition, the following should be noted : The presence of bristles relatively constant in length, five placed symmetrically on each side of the dorsal surface; some similar bristles, though few in number, on the ventral surface and on several segments of the legs. The male has triangular abdominal lobes furnished with five bristles, the three terminal ones being the largest ; the first three pairs of legs are complete, but the fourth pair are very short, and have Fig. 71. — PKOroptts communis, var. eijiii : an ovigeious female, seen uii the ventral surface ; magnitied one hundred diameters. no ambulacral suckers. In the ovigcroiis female, the lips of the vulva are much plicated, and the commissures rest on two arched pieces, which are divergent and directed backwards. There is an ambulacral sucker on all the legs except the third pair, which are terminated by two long bristles. The pubescent female is recognised by her smaller size, the large vulvo-anal slit, the absence of a sub-thoracic vulva and of the ambulacral sucker on the fourth pair of legs; in addition, beneath the dorsal surface, and on each side of the posterior commissure of the cloacal slit, are two hemispherical prominences (copulatory tubercles) which assist iu copulation by being received into the copulatory suckers of the male. The nymplia, has not these tubercles. The larva has the third pair of legs terminating in suckers. ACARIASES. 127 The common Psoiopt does not make sub-epidermic galleries like the Sarcopt ; it lives, in society, among the crusts which it forms by prick- ing the skin of its host. It produces special dermatoses on the Horse, Ox, Buffalo,^ Sheep, Goat, and Eabbit. Here, again, the difference of habitat coincides with the existence of varieties, which are scarcely distinguishable from each other by their size and unimportant details, but which, according to their hosts, are designated by the names of Psoroptes communis cqiii, Ps. c. bovis, Ps. c. ovis, Ps. c. caprce, and Ps. c. cunicuU. Their average dimensions are: for the ovigerous female Fig. 75. — Psoroptea communis, var. eqid: pubes- cent female, seen on the ventral surface ; magnified one hundred diameters. Fig. 76. — Psoroptes communis, var. eqid : hexapod larva, seen on the ventral surface ; magnified one hundred diameters. •65 mm., and male -48 mm. long; and for the former -40 mm., and latter -30 mm. broad. Otherwise, in the absence of information as to their source, there are no special features which will allow one variety to be certainly distinguished from another. Symbiotes. — The genus Symbiot comprises four species — the common Symbiot, the auricular Symbiot, the setifer Symbiot, and the ancestral Symbiot. The setifer Symbiot (Si/mbiotes setifer Meg.) has been found by Megnin on the Hyena and Fox ; the ancestral Symbiot (S. avus Trt.) has been discovered by Trouessart on the Sparrow. We need not describe these two kinds of Symbiot. M^gnin. Comptes Rendus de la Soc. de Biologie, November 28, 188t 128 TREATISE ON PABASITIC DISEASES. Common Symbiot (-S'. commnniH Yerheyen, S. sjiatltiferuH Megnin). — This has on the middle of the back a wide, granular, chitiuous band, twice as broad behind as in front, with its borders concave outwardly, and extending from the margin of the epistoma to the point of origin of the second pair of legs. Behind each of the two posterior angles of this band is a short hair, and behind, but near it, are two long bristles ; there are several other parts of the body which, though constant, vary in number, length, and situation according to the sexes. The vialc has its rectangular abdominal lobes, each carrying four bristles at their extremity — one ordinary, external, round, and free ; three grouped at Fici. 77. — Symbiotescoinmiuiitt, var. eqiii: male, Fu;. 7S. — SymliiottxcotnjHUJii'i.va.T. etjUi: seen on the ventral surface ; magnified one an ovigerous female, seen on the ven- hundied diameters. tral surface ; magnified one hundred diameters. their base, one of them being similar to the preceding, the two others lie on each other and are widened to form a thin foliaceous membrane. The four pairs of legs are provided with ambulacral suckers ; the fourth pair are thin and short. The ovigerous female has the lips of the ovigerous vulva very much plicated, and in contact, by their commissures, with two pieces similar to those of the ovigerous female of the Psoroptcs commnnis. It has an ambulacral sucker on all its feet, except the third pair, which have two long bristles. The lyuhcsccnt female differs from ACAEIASES. 129 the preceding by the same peculiarities as the Psorojjtes communis; and the same observations apply to the nympka and the larval hexapod. The length of the ovigerous female is -36 mm. to -40 mm., and the male •28 mm. to -32 mm., while the breadth of the former is -23 mm. to •26 mm., and the latter ^21 mm. to -24 mm. The common Symbiot lives in the same manner as the common Psoropt— in colonies, and without excavating sub-epidermic galleries. It causes a locahzed scabies, the extension of which is slow, and which TiG.I'd.— Symh'iotes commi(nis,v2iT. er/MJ.-pubes- Fig. 80. — Symhiotesauricidnrum of the cent female, seen on the ventral surface ; Dog : male, seen on the ventral sur- magnitied one hundred diameters. face ; magnified one hundred dia- meters. — Railliet. is more particularly observed on the Horse and Ox ; but it has also been witnessed on the Goat, Sheep, and Eabbit (?). The varieties eqid, hovis, caprce, oris, and cuniculi (?) might also be distinguished here. The Auricular Symbiot (S. anricularum Lucas and Nicolet, Chori- optcs ecaudatiis Megnin, Sarcoptes cynotis Hering) differs from the preceding species principally by the absence of the abdominal lobes in the male, which are represented by two small round projections separated by a notch, each of them having three bristles, the middle one of which is very long. The ovigerous female has no suckers on the 130 TKEATISE ON PARASITIC DISEASES. two last pairs of legs, and the fourth pair of legs are rudimentary ; while the jnibescent female has the fourth pair of legs reduced to simple knobs carrying one "hair each. The length of the ovigerous female is •42 mm. to -49 mm., and the male -30 mm. to -34 mm. ; the breadth of the former being -29 mm. to -31 mm., and of the latter -23 mm. to •28 mm. This species lives in the auricular concha of the Dog, Cat, and Ferret, and gives rise to a disease which is very remarkable because of the nervous disturbance accompanying it. The foregoing zoological remarks will suffice to indicate the genera and species of the Sarcoptinai that are likely to be met with. In such Fig. 81.— Symbiotes anricularum of the Dog : an ovigerous female, seen on the ventral surface ; magnified one hundred diameters. — Railliet. a determination great assistance will be afforded by a knowledge of the host from which the parasites have been derived, and the character of the lesions they have produced — that is, by the study of the various forms of scabies. General Nosography. — The various domesticated animals may serve as hosts to the Acarina of one, two, or three genera of Sarcoptinae. By their pricking, and, no doubt, also by the irritant saliva they dis- charge, these parasites excite an alteration in the skin which is mani- ACARIASES. 131 fested by redness, loss of hair, thickenings, effusions, crusts, and an intense pruritus. The redness can only be perceived on skin destitute of pigment, and then it is one of the most marked signs of the disease. The thickening is little observable at the commencement, but it gradually increases because of the continued irritation of the parasite, and the energetic friction which the animals apply to it under the influence of the pruritus. In some parts — as the extremities, where the skin is thick and covers only a small amount of connective tissue — it becomes augmented in thickness ; but where the skin is thin, movable, and only shghtly adherent — as on the face, neck and shoulders, sides, etc. — it forms thick folds and deep ridges, which give the animal an altogether pecuhar physiognomy. The bottom of the ridges is moist and often excoriated ; the majority of the hairs, if not all, are removed by the rubbings and the morbid process ; and at the same time the secretions of the super- active and altered skin lead to the formation of crusts which are irregu- lar in shape, thickness, and distribution, and are composed of serum, dried blood, epidermic (Uhris, hairs, etc. The pruritus, which contributes so much, by the frictions it provokes, to produce this alteration in the skin, is of variable intensity, according to the temperament of the affected animals, the seat and extent of the disease, and the time of day. It is particularly intense during the night, causing loss of sleep (and rest), which, added to the restlessness during the day and the disturbed cutaneous functions, induces debility and emaciation, and leads to marasmus when the malady has been widely extended. The characters of scabies are more particularly subordinate to the kind of parasite producing it. In this respect it is difficult to establish any general rules, as we do not find between the Psoroptes and the Symbiotes differences in habits analogous to those which separate the two species of Sarcoptes. That which especially characterizes the latter is the fact that the ovigerous female, immediately after fecunda- tion, excavates in the substance of the epidermis a gallery or furrow {cunicuhis), in which it deposits its eggs ; consequently, it happens that sarcoptic scabies offers a greater resistance to the action of curative agents. Other differences belong to the seat preferred by the parasite. There are scabies which may appear on all parts of the body ; others that always commence at the same points and extend to other regions ; and others, again, which are very localized. All these differences will be inclicated in their place. An essential element in diagnosis being the detection of the parasite, care should be devoted to this. But sarcoptic scabies offers the greatest difi&culties in this respect. The following recommendations, given by 9—2 132 TREATISE ON PARASITIC DISEASES. :\Iegnin for the scabies of the Horse, are equally apphcable for all the other domestic animals. "When the weather is cold or windy, it is difficult to find the Sar- coptes, and to be successful in the search it is best to have calm weather and sunshine, to which the mangy Horse should be exposed. After about an hour of this exposure, the crusts and debris are collected from the diseased parts ; but one must not be satisfied with the crusts that are most easily removed, for on them may be found nothing more than some larval hexapods which have a more superficial habitat than the adults. To obtain the latter, it is necessary to scrape the surface to the blood, through the entire thickness of the epidermis, with a sharp or slightly blunt instrument. Amongst Horses equally mangy in ap- pearance, some will be found which do not nourish nearly so many Sarcoptes as others ; and the inverse is equally true, for lymphatic Horses which have the thickest and most abundant crusts, have fewest parasites, while Horses of a nervous, wiry temperament have them in largest numbers. It is, of course, understood that it is only on mangy Horses which have not been submitted to any treatment that a search for the parasites is likely to be successful ; for it often happens that with those which have been treated, the scabies has disappeared, and in its place is a chronic or artificial lichen if the treatment has been too energetic. When a good quantity of crusts has been collected, these are put in a well-heated box, and if possible at a window exposed to the sun — for without this precaution the Sarcoptes will remain motionless, and can only be distinguished with difficulty from the dust in which they lie. A small quantity of this dust is spread on a glass plate, and examined in the microscope by a power of 40 or 50 diameters — direct, and not reflected light being employed. Under the influence of the sunlight, the Sar- coptes can be seen disengaging themselves gradually from the masses of dust or crusts covering them ; then with the point of a handled needle they are carefully isolated from the foreign matter surrounding them, and lifted by the needle or a fine brush on to a drop of glycerine on another glass. After placing over them a covering glass, but without compressing them, they may be studied alive, in their true form, and magnified to any size — that of 150 to 300 diameters to examine the general conformation, and from 400 to 500 diameters for details of structure. It may be added that the operation may often be successfully simpli- fied by warming the surface of the Horse's body by means of a blanket, and that the activity of the Sarcoptes can be excited by exposing them to the gentle heat of a fire — their movements being rendered visible in examining the crusts on a piece of black paper, by means of a good hand-lens. A procedure that avoids loss of time and patience, as well as errors^ ACAKIASES. 133 consists in immersing the crusts for an hour or two in a 10 per cent, soktion of potass, and then examining them ; when it will be found that they have become diffluent and colourless, are easily spread out under the cover-glass, and the Sarcoptes whose skin resists the alkaline solution, can then be very readily seen. We have many times sue ceeded in this way, after failing in every other, notwithstanding all our perseverance. By reason of their relatively greater dimensions, the Psoroptes and Symbiotes are readily found, even by the hand-glass, among the crusts, where they can be seen moving. Care must be taken not to confound the psoric SarcoptidcE with other Acarina — dead or alive — that may be found on animals, and which come from forage — such as the Tyroglyphae, Glyciphages, Cheyletes, Gamases, etc. An attentive examination will avert this error, for the characters we have described as peculiar to the first will not allow of such a mistake. With regard to the etiology of scabies, it is needless to refer to the hypotheses found in ancient medicine to explain their genesis. We say nothing of the humoral theories, which had their day, nor of the 'psoric vice,' nor of spontaneous generation, to which there was a tendency recently to attribute the appearance of the psoric Acarina. It is to-day beyond dispute that for an animal to have the mange, it must have received the principle of the disease — the contagium, the acarus — from another mangy animal with which it has been in immediate or mediate contact. Numerous experiments have established that fact, so far as animals are concerned ; on every occasion on which an outbreak of mange has been traced to its source, it has been ascertained that it was introduced by a mangy subject ; in every case a psoric Sarcopt can be found ; the means which cure the mange also destroy the parasite ; lastly, direct experiment confirms the doctrine. Hertwig has inoculated animals — by friction and by puncture — with serum from the vesicles, with pus, and with dry and dissolved crusts, and yet failed to produce mange. On one occasion, when he neglected to assure himself that the products with which he inoculated did not contain ova or acari, a psoric eruption resulted. Hering tested these experiments, and came to the same con- clusions as Hertwig ; and Delafond and Boui-guignon, as well as Gerlach, arrived at identical results. The constant correlation between the Acarina and the psoric eruption cannot therefore be disputed. It is not the movement of the parasites which causes the irritation and the pruritus. The Sarcopt is not felt when it wanders on the surface of the skin, nor yet when it is burrowing into that membrane. What induces the itching is an irritant principle deposited by the para- site in the living portion of the integument. Bourguignon has obtained 134 TKEATISE OX PAEASITIC DISEASES. a vesicular eruption by inoculating crushed acari, or the fluid derived from them ; and he therefore justly concluded that the animalcule secretes an acrid matter which it insinuates into the skin. But he erroneously believed that this matter, when absorbed, would produce a general eruption. It is a long time since Hertwig practised transfusion of blood from a mangy to a healthy animal of the same species, without result ; and it is well known that when a Sarcopt is placed on the skin of Man, the papule and vesicle appearing soon after, always correspond to the precise point of the integument pierced by the animalcule. Gerlach has given a complete demonstration of the purely local effects of the matter secreted by the acarus. With a very fine needle he traced a groove in the epidermis, and then moistening the point of the instrument with fluid from the crushed parasite, he reintroduced it into the epidermis, but only experienced a vague sensation ; but when the point of the needle reached the derma, there was instantaneous pain, succeeded by a papule and a vesicle, with pruritus. By this mode of procedure, Gerlach satisfied himself that the Psoroptes secrete the most acrid fluid, then the Sarcoptes, and, lastly, the Symbiotes. All these facts thoroughly establish the predominating, essential, and exclusive part the parasite plays, locally and specifically. Ought there to be admitted, besides this, a predisposition — if not necessary, at least favourable — to the development of the disease ? Delafond and Bourguignon, in particular, have replied to this question in the affirmative ; their observations were in relation to the scabies of Sheep, and the response was made with them. With regard to the Horse and the other domesticated animals, it is true that weak, badly nourished, dirty, and neglected creatures are more frequently attacked than those in the opposite conditions. But this is only owing to the unclean state of the animals themselves — to the filthy litter, coverings, harness, and insufficient grooming. The parasites, being left in almost absolute tranquillity, can multiply at leisure, and the mange extends gradually on the same animal, or from an affected to a healthy one — not because of its constitutional weakness, but rather because of its unsani- tary condition and the natural course of contagion ; and it is to these circumstances that must be attributed those epizootics of mange which usually occur during wars, and among great agglomerations of Horses, and which are so serious for the public treasury. The treatment of scabies consists in the employment of so-called anti- lisoric or acaricide remedies, which act by reason of their toxic properties on the Sarcoptinai. They are extremely numerous and varied. In choosing them we are guided by the kind of scabies which is to be treated, the nature of the affected animal, its species, age, size, and susceptibility ; as well as the resources at our disposal, and especially the particular activity of each of the remedies. Tn the following table, Verheyen has given interesting indications ACAEIASES. 135 with regard to the principal agents tried and their acaricide properties. They are principally the result of the researches of Walz, Hertwig, Eeynal, Mathieu, and Gerlach, which consisted in putting the animal- culse in contact with the various substances, and noting, by means of the microscope, the moment when death occurred. Creosote, benzine, and naphtha Preparations of these materials Juice of tobacco from the manufactories Solution of caustic potass (1 to 24) - Enipyreumatic oil - Oil of turpentine and petroleum Diluted sulphuric acid (1 to 24) Tar - - - - - Ferro-arsenical solution of Tessier - Decoction of tobacco (1 to 5) Solution of chloride of lime (1 to 30) ,, of sulphiiret of potassium (1 to 10) ,, of corrosive sublimate (1 to 46) ,, alumino-arsenical of Mathieu Soft soap . . - . - Phosphuretted oil - Saturated arsenical solution (1 to 6) Double mercurial ointment - Dpcoction of black and white hellebore (1 to 16) Walz's wash - - - - - Liniment of sulphuret of potassium (1 to 10) Infusion of henbane and belladouna ,, digitalis purpurea An absolute signification cannot be accorded to these figures, the experimental resistance of the Acarina being, in fact, subordinate to their vitality at the moment of testing. Von Schroder, by analogous researches, obtained somewhat different results from the above. As a general rule, treatment should be preceded by complete removal of the hair from the whole of the body, unless the disease is strictly localized, in which case partial clipping may suffice. Then there should be general washing, by means of a coarse brush, with alkaline or soapy water. Then the selected remedy is be applied. In four or five days afterwards the washing and dressing are to be repeated, in order to destroy the Acarina recently from the eggs, and which the first treat- ment could not reach. If there is emaciation and tendency to cachexia, the food should be substantial and abundant. The following sketch, which is conformable with the conditions of practice, deals successively with the different kinds of mange in all the domesticated Mammalia ; but for the present no reference is made to the auricular acariases due to the Psoroptes or Symbiotes, as owing to their very localized seat, their symptoms, and their lesions, they are distinct from the psoric acariases, properly so called, and also because, from the plan of this work, their place is more naturally among the parasitic diseases of the sensory organs. DURATION OF LIFE. Hour.i. Minutes. ■ I ito 1 2 „ 5i * „ 1 - 2^ „ 2^ 3 „ 4 5 „ 9 ... 7 „ 8 - 8 „ 13 7 ,. 25 10 „ 20 15 „ 30 15 „ 30 15 „ 45 16 „ 65 30 „ 60 1 - 2 to 3 '.'.'. 4 - 6 to 36 - 6 „ 48 - 10 „ 20 ... - 12 „ 16 ... - 24 „ 36 ... 136 TREATISE ON PARASITIC DISEASES. A.— Scabies of the Equidae. The Horse, Ass, aud Mule are affected with three kinds of scabies : 1. Sarcoptic scabies, due to the Sarcoptes scabiei (variety eg ?ti) ; 2. Psor- optic scabies, due to the Psoroptcs communis (variety cqiii); 3. Symbiotic scabies, due to the Symbiotes communis (variety cqui). These different forms have been chiefly observed on the Horse. 1. Sarcoptic Scabies. This form of scabies is probably that which authorities have described as t'le dry mange (gale seche La Gueriniere), symptomatic mange {gale symptoniati(iuc Huzard, jun.), cpizodlic mange, etc. Our knowledge of its nature — that is, of the discovery of the Sarcopt which causes it — is due to Delafond and to Gerlach, who, about the same time — 1856 — found it upon the Horse, and gave a description of it. The epizooty that prevailed among the Horses of the French army during the war in the Crimea, may certainly be ascribed to this parasite, though it v^as then attributed to misery, privations, bad forage, etc.^ The same observation has been made after the war (Franco-German) of 1370 and 1871.2 Symptoms.^ — The first sign of the disease is pruritis. The animal seeks to rub itself everywhere; it bites itself wherever it can reach, and appears to enjoy, and even seeks, the contact of the currycomb during grooming, leaning towards the groom as if to accentuate its desire. If scratched by the fingers, it manifests its pleasure by very characteristic movement of the nose and upper lip, and this is a provisional means of assuring one's self of the existence of the disease, as well as of the reality of its being cured. This pruritus is greater at night than during the day, in warm than in cold weather, in the stable than out of it, when clothed than unclothed. An attentive examination of the skin will reveal the presence of the mange papules at the pruriginous parts. When the hand is passed over the surface of the skin, slight prominences or granules are felt, and which are formed of a little crust around one, two, or three hairs ; this is easily removed by the finger-nail, and then there is left in its place a red, moist, denuded surface about 2 mm., or sometimes 4 or 5 mm. in diameter. At other points, mixed with the crusted patches, are slightly salient papules which are scarcely visible — this is the first degree of the preceding lesion, the papule raising its epidermis by a serous effusion that gradually dries and forms a crust. In the earlier stage these small (1 The horses and transport animals — mnles and camels — of the P.ritish army in the Crimea equally suffered from 'mange,' which was recognised as such by the veterinary officers. I and others never had any doubt as to the nature of the terrible scourge, while having to contend with it. — See the Veterinarian for 1857, p. 264, and my ' Veterinary Sanitary Science and Police,' vol. ii., p. 407.) (" For a history of scabies, and an account of the various serious outbreaks recorded — especially among army horses, see my ' History of Animal Plagues,' vols. i. and ii.) ACARIASES. 137 lesions are disseminated; they bring about the fall of the hairs in small, nearly circular patches, which are multiplied and extended, and finally become confluent, forming large dry patches covered with epidermic (Uhris and sparse thin crusts. It is very rare that any vesicles are seen, as their duration is very ephemeral, the friction caused by the pruritus quickly replacing them by crusts. The depilated patches ex- tend and, by a rapid generali- zation, finish by invading the entire surface of the body except the limbs. The animal then presents a particularly miserable appearance. The brilliancy of the coat has van- ished ; large patches with sinuous borders, dusty and grayish in colour, uneven and crusted — often bleeding — on the surface, impinge on the yet hairy portions. A par- ticular feature is the limit of the patches, which is always undecided ; and in the adjoin- ing parts, which at first sight appear to be healthy, the initial lesions of the malady are recognised. The skin becomes consider- ably thickened, and in the re- gions where it is attached to the subjacent parts by a loose connective tissue, it is raised into hard, thick folds ; these are more especially observed about the neck and shoulders. Friction is a very important agent in bringing about the alterations in the skin; it excoriates the papules, accelerates the formation of the crusts, produces subcutaneous infiltrations, haemor- rhagic exudations, pustules, fissures, and ulcers. Besides the pruritis and the eruption, a third symptom— and the most important, as it is the only pathognomonic one— is the presence Fig. 82.— Sarcopt of Man. A fecundated female (s) forming its gallery or burrow. A semi-diagrammatic figure, partly after Gerlach. Fmm before to behind .are seen the eggs increasingly older, «, a.', «", then some empty egg cases of the larva ; e, o, opening for the escape excrements. lots TKEATISE ON PARASITIC DISEASES. of the Sarcoptes. The uymphge, and the adult males and females, are met with among the crusts on every part attacked. The young larvae and the ovigerous females live in the intra-epidermic galleries or grooves which, in Man, are indicated by a fine red line, from 10 mm. to 20 mm. long. These galleries are not visible in the Horse, because of the pigmen- tation of the skin and the thickness of the epidermis. They are excavated by the female immediately after copulation ; and they are rapidly formed, for in from 15 to 30 minutes the work is completed, and all the more promptly if the temperature be elevated. It is for this reason that these parasites have been considered as noctambulant ; if they torment animals more by night than by day, it is because then the conditions of temperature — warm stable, litter, and probably clothing — are more favourable. At the point where the Sarcopt penetrates, an inflammatory papule forms, but the parasite is not to be found beneath it, but at the other extremity of its gallery. The female lays its eggs in this gallery, one after the other, and here they are seen mixed with excrements. The larvae which issue from them are nourished in the gallery for some time, and may even undergo moultings before making their exit by the small orifices that are seen along the course of the passage, and which were believed to be air-holes. It is not certain whether the nymphae and pubescent females also live in the galleries. In any case, copulation takes place Fig. 83.— Egg of the Sarcoptes xcabiei, in various stages of development ; magnified 150 diameters. beneath the crusts and the epi- dermic scales ; it is of short duration, and the males are relatively few, their proportion being estimated at only 5 or 6 per cent, of the total number. The habits of the Sarcoptes explain the greater tenacity of this form of scabies, as well as its more rapid extension — from the fact that the para- sites escape ordinary causes of destruction — and the difficulty in finding them. The latter object can be achieved by the procedure indicated at p. 132. It is rarely necessaiy to resort to that recommended by Gerlach — transferring the acari to a Man, and then searching for them on him. To do this, the experimentalist places on his arm some of the crusts from the suspected animal, fixing it by means of a piece of tissue paper covered by oiled silk or a silk ribbon. In about twelve hours the Sar- coptes have penetrated the skin, and on removing the crusts they can be seen as white points beneath the slightly congested membrane, or on a papule, and they may be seized by means of a fine needle. If we wait until the papule becomes a vesicle, the acarus is no longer there, as it has traced its gallery. This diagnostic procedure does not cause any ACAKIASES. 139 inconvenience, as a little oil of turpentine or any other acaricide will avert contagion. Course, Duration, and Termination.— Sarcoptic scabies is some- what slow at its commencement ; so that it may remain unperceived for some time. A small number of acari do not give rise to anything very marked during the first fifteen days of their installation, and it is only during the succeeding fifteen days that the phenomena of invasion are manifested, although they are still sufficiently vague as to make diagnosis doubtful. The affection is more clearly revealed in the course of the third fortnight, and during the fourth it has made more progress than in the previous six weeks (Gerlach). Nevertheless, when circum- stances are favourable, the extension of the disease may be at least twice as rapid, and the incubative period be reduced to fifteen days. It would seem, therefore, that the prosperity of the colony is absolutely conformable to the geometrical progression of the m.ultiplication of the parasites, as given by Gerlach (see p. 120). When the disease is well established on an animal, it may within eight days have reached parts of the body the most distant from where it commenced. Sarcoptic scabies begins most frequently at the withers, and extends to the sides of the neck, shoulders, back, and sides. It does not easily invade the extremity of the limbs, and it respects the parts covered with strong hairs — crest, tail, legs — which remain with their hairy covering in the midst of neighbouring denuded regions. The Psoropt, on the contrary, appears to seek those parts exempted by the Sarcopt. Sometimes, though rarely, Sarcoptic scabies commences at the head, flanks, croup, etc., this depending upon the initial point of contamina- tion. "When the disease is not interfered with, by the disturbance in the functions of the skin and the restlessness due to the pruritus, it occa- sions a serious alteration in nutrition and marked marasmus that may, if slowly, lead to a fatal termination. Such a result, however, is only witnessed among animals which have not received sufficient attention ; and as diseased animals are not the objects of careful observation, and as nearly always the malady is interfered with in its course by more or less judicious treatment, there is no reliable information with regard to the minimum, average, or maximum duration of this kind of scabies. On a Horse which has been recently cured of mange, the hairs grow unusually fast, owing to the greater activity of the capillary circulation of the skin ; they are longer than the neighbouring hairs that remained healthy and were clipped in treatment, while their colour is generally darker ; this difference is perceived until the next shedding of the coat. Etiology, Contagion.— All experiments and observations demon- strate the contagiousness of sarcoptic scabies from the Horse to other Horses, Asses, or Mules, and reciprocally. This transmission takes 140 TREATISE OX TARASITIC DISEASES. place in every way by which the parasite can be transported, and principally by litter, rugs, grooming utensils, walls of stables and partitions of stalls. It also occurs, though less frequently, by direct contact of diseased with healthy Horses. The mange which prevailed among the French army Horses in the Crimea made startling progress during the voyage, owing to their being so closely packed in the transports ; and here we have a proof of the direct transmission of the Sarcoptes, all the Horses having been attacked with the malady on the parts where they came into contact with each other (Delafond and Bourguignon). The danger of contagion is related to the phase and intensity of the disease. At the period of their installation, the Sarcoptes have little tendency to emigrate, and cohabitation of healthy Horses with one which is just infected is often followed by no bad results ; but after the formation of scales and crusts, the parasites pass quickly from one Horse to another, a slight and fugitive contact between them being sufiBcient to ensure infection. Gerlach asserts that he has seen Horses in good health, placed alongside mangy horses covered with crusts, contract the disease in a quarter of an hour. The larvae and nymphoe, and the young fecundated females and males, are more especially the active agents in transmitting the malady. The egg-laying females, concealed in the galleries, scarcely concur in this transmission, unless they are violently exposed by energetic scratching which reaches the blood. With regard to the persistency of contagion by articles from mangy animals, and which harbour the Sarcoptes, Gerlach on the one side, and Delafond and Bourguignon on the other, have made interesting experi- ments as to the vital tenacity of the parasites. According to Gerlach, no variety of the Sarcopt exposed to a dry heat of 60° (Cent.) can live beyond an hour. Kept in a watch-glass, the Sarcopt of the Horse died on the fifth or sixth day ; with the crusts, it lived eight or ten days ; and in an inhabited stable, death only took place on the twelfth to the fourteenth day. On a fragment of skin covered with crusts, and exposed to heat, the Sarcopt perished when the piece was completely dried, which was on the ninth day ; when the skin preserved its humidity, the animalcule gave feeble signs of life on the twenty-fourth day, but these had entirely ceased on the twenty- eighth day. Delafond and Bourguignon have obtained similar results. The Sarcopt of the Horse being only a variety of the Sarcoptes scabiei, it is well to know if the Horse can contract sarcoptic mange by mediate or immediate contact with any other of the Mammalian species susceptible of being affected with a similar form of the disease. So far as the scabies of Man is concerned, Delafond and Bourguignon have, on different occasions and in the space of forty days, deposited ACARIASES. 141 on the skin of an old and feeble Horse 176 Sarcoptes obtained from people affected with itch. These parasites attacked the skin, buried themselves in the epidermis, and produced a papulo-vesicular eruption on the shoulders and neck. The Horse died on the fourteenth day, and at the autopsy it was impossible to find any of the parasites on the skin. In another experiment, 187 Sarcoptes, collected from affected Men, were deposited at several times within twenty-six days on the side of the neck of an old lean Horse. They traced numerous galleries and occasioned a vesicular eruption ; but this disappeared, and on the animal being chpped on the seventy-ninth day, there was no evidence of scabies or parasites. These experiments demonstrate that the Sarcopt of Man will only temporarily implant itself on the skin of the Horse, and that there is nothing to fear from Men suffering from itch attending Horses. We cannot be so certain with regard to the transmission of the Sarcopt of the Dog to the Horse. In three experiments made by Delafond and Bourguignon, great numbers of the Sarcoptes of the Dog — 110, 58, and 220 — were placed on the skins of two Horses ; they attacked the integument, raised the epidermis, and made galleries ; living for twenty to twenty-four days, they occasioned a secondary eruption, accompanied by the majority of the symptoms of mange : but they eventually died, and the symptoms spontaneously subsided. Gerlach has also made some attempts at transmission, which have likewise yielded undecisive results. He believed, however, that an emigration en masse of the Sarcopt of the Dog might give rise to a transient eruption on the skin of the Horse ; and he thought that to this cause might be attributed the mange contracted by horses — according to the statements of hunting-men — when mangy Foxes, killed in the chase, are thrown over the backs of their steeds. It is also interesting to note the fact of the transmission of mange from the Lion to the Horse, as observed by Delafond and Bourguignon. Five Lions in a menagerie were affected with sarcoptic scabies. The brush and sponge employed to clean their skins were used for some days in grooming six Horses ; in about seven to nine days afterwards, the latter had a very pruriginous papular eruption on the croup, back, shoulders and chest, and in the crusts collected from them were found the Sarcoptes of the Lion. This mange was readily cured by the application of benzine, but it is probable that it would have disappeared spontaneously. A similar observation is cited by the same authors, to that made by Hertwig, in which it is a question of a Cat communicating mange to a Horse, through resting on the back of the latter. Lastly, the sarcoptic scabies of Goats has been transmitted to Horses, in an epizooty reported by Wallraff.^ Comvmnicatiou of the Sarcoptic Scabies of the Horse to other Species of 1 Wallraff. Repertorium der Thierheilkunde, 1 854, p. 297. 142 TREATISE ON PARASITIC DISEASES. Mammalia. — A. Man} — The sarcoptic scabies of the Horse may be transmitted to Man, although this occm-rence is comparatively rare. For a long time instances have been recorded — long before the three kinds of Horse mange had been distinguished. The greater portion of the following resume is taken from Delafond and Bourguignon's work. Enaux and Chaussier have recorded cases of contagion of mange of the Horse to Man, Chabert asserts that he, as well as several other veterinary surgeons, had caught mange from Horses ; and Delabere- Blaine also gives an instance. Chavassieu d'Audebert advanced the opinion that mange may be communicated from the Horse to Man. Barat i-eported to the Lyons Veterinary School, an instance of several persons having received mange from a Horse. Grognier relates that a mangy Horse had communicated its disease to a number of people who had dressed it before it was sent to the Lyons Veterinary School. Eobert Fauvet, an Italian veterinary surgeon, states that a farmer having bought a mangy horse, rode it home, and the day after his arrival he felt a great itching all over his body ; the same was the case with his son and a friend who had accompanied him on the journey. The groom to whom he had entrusted the horse, scratched himself very much the second day after he had been grooming the animal. These persons afterwards conveyed the disease to others on the farm, and more than thirty persons were successively attacked. The farmer sold the mangy horse to a miller, who, with his sons, who had touched the animal, were soon after suffering from the itch. The psoric nature of the affection was recognised by distinguished physicians. Montaut-Laforest reports a case of contagion to Man from a mangy Mule. Lavergne, Carrere, Girou, Soule, Greve, Pachur, Hertwig, and Stiitz, have published very circumstantial facts in relation to this conveyance of Horse scabies to Man. Sick mentions an epizooty of mange in a regiment of Hussars, and more than one hundred of the soldiers being infected. Marrel, a veterinary surgeon at Valreas, Vaucluse (France), was attacked by the disease when treating mangy horses, and saw the same accident happen to a farmer, who communicated the malady to his wife, and she to a child she was suckling ; four other children who '»vere attended to by the mother were also infected. Dupont, veterinary surgeon at Bordeaux, sent on an official mission, reported cases of people being infected with mange fi'om old Horses kept to feed the leeches in the marshy districts of the Gironde. Eitter reports having been himself, as well as a servant, infected while attending on a mangy Horse. ^ Enaux and Chaussier. Man. nur la Pusfide 3falii/»e, 1785, p. 3. — Delabere-Blaine. NotiouH foiidum. sur CArt V itcriimire, French translation, 1803, III., p. 404. — Chavassieu d'Audebert. Tr. den Exanthemen Epizootiqnex, 1804, p. 23. — Barat. Compte Rendu de I'Ecole de Lyon, 1815. — Grognier. Jbkl., 1817. — Robert Fauvet. Annali Universi diMedicina, 1823. Rec. deM^d. V^terinaire, 1824, p. 152. — Laforest. Compte Rendu de la Soc. d'Agric. de Paris, 1822, p. 58. — Lavergne, Carrere. Girou, Soul^. Journal dts V^t^r, du Midi, 1838, pp. 52, 237. — Greve, I'achur, Hertwig, Stutz, Sick. Journal V^ter. et Agric. de Belgique, 1842, p. 329. — Ner^e (iot. De la dale de I'Homme et den Anhnaux, produ'Ue par les Acarea, etc., Thtise de Paris, 1844. — Marrel. Rec de Med. Vet^r., 1847, p. 1000. — Dupont. Journal des V«^ter. du Midi, 1854, p. 524. — Ritter. Annales de M^d. Veter., Brussels, 1855, p. GOO. — Geraud. Kec. de Mem. de Med. Militaires, 1881. ACAKIASES. 143 In 1856, several pupils of the Alfort Veterinary School contracted the itch through operating upon a mangy Horse. This was the occasion on which Delafond discovered that this form of scabies was due to a Sarcopt, and which he considered was identical with that of Man. The discovery raised the number of species of psoric Acarina of the Horse to three. Gerlach, in the experiments on himself and several pupils of the Berlin Veterinary School, has seen the Sarcopt of the Horse fix itself on the human skin, like the Sarcopt special to Man, and cause an itch that was generally fugaceous. Megnin has also observed instances of contagion to Man, during the epizooty of mange prevailing among the Horses of the French army in 1871. (In the Crimea, I saw a large number of Turks suffering severely from itch, due to their sleeping on the saddles and blankets worn by their Horses, whose skins were covered with mange. ^ Longchamps informs us that, in 1794, the Horses and Mules of the French army in the South of France were affected w^ith mange to a very serious extent, and that the disease was transmitted to, and propagated among, the soldiers.-) Geraud has also published instances, and a great number of others will be found in the thesis of Neree Got. All these facts prove that the sarcoptic scabies of the Horse can be transmitted to Man, and also that the parasite does not find a favour- able soil for its multiplication, as the itch it produces generally disappears spontaneously in from fifteen days to six weeks ; but in any case it readily yields to simple treatment, such as alkaline and sulphur lotions. A proof of the difficulty of this transmission is also to be found in its rarity, when compared wdth the frequency of sarcoptic scabies in the Horse. In the epizooties of mange occurring among the Horses of the French army during great wars, it has been quite exceptional that cases of the conveyance of the disease to Man have been noted ; and if the itch caused serious disability among the soldiers during the Crimean War, it is not clearly established that its origin was due to mange among the Horses, w'hich was the opinion widely prevalent ; and though many cases were adduced as being derived from this source, yet the evidence is not so satisfactory as could be desired. But an exaggerated significance should not be given to this rarity of contagion, for the transmission from Man to Man is not as subtle as is generally believed. ' The itch,' says Besnier and Doyon, ' is not usually contracted except by cohabitation — intimate contact prolonged and re- peated, and particularly at night ; it must not be affirmed that this never happens accidentally , but it is sufficient to know that it is exceptional.'^ B. Domesticated Animals. — Sarcoptic scabies of the Horse appears {} Veterinary Sanitary Science and Police, London, 1875, vol. ii., p. 418.) (- Ibkl.) ^ Besnier et Doyon. L^oim sur lea Maladks ih la Peau, by Moritz Ka^wtl. French translation, II., p. 481, Paris, 1881. 144 TREATISE ON PARASITIC DISEASES. to be capable of transmission to the bovine species, although up to the present time no one in practice has observed this form of mange on Cattle. The possibility of this transmission rests on facts published by Eobert Fauvet and Grognier, of which mention has already been made (p. 142). The Horse of Fauvet communicated mange to a Cow which had rubbed its neck against the manger of that animal. The Horse of which Grognier speaks, transmitted its disease to two Cows placed alongside it in the stable. Beyond these facts, where the sarcoptic nature of mange of the Horse was established by its transmission to Man, but where the equine origin of bovine mange was not sufhciently demonstrated, there are doubts as to the possibility of this transmission. Neither is there any more authority for stating that Horse mange may be communicated to the Sheep, Goat, Dog, etc. Diagnosis. — An important element in diagnosis is the discovery of the Sarcopt, with all its characteristics. Sarcoptic scabies differs from psoroptic scabies, as we shall see hereafter, by its more rapid generaliza- tion, by its more subtle contagion, and by its seat — psoroptic scabies commencing and localizing itself nearly always at the upper part of the neck, towards the forelock and the tail, which become denuded of hair, tumified and wrinkled. Psoroptic scabies also assumes a form in which the patches are better defined, they being tumified at the base, crusted, and more humid. Sarcoptic scabies differs from symbiotic scabies in the latter being confined to the limbs at first, commencing at their most inferior parts, and slowly extending upwards ; it is also only feebly contagious. Otherwise, the three forms of scabies may co-exist, and the remem- brance of this important fact may avert grave errors in diagnosis. At its commencement, sarcoptic scabies is diificult to diagnose from dermanyssic acariasis — due to the transference of the Dermanyssis of the Fowl to the body of the Horse. But it is distinguished from it, nevertheless, in the latter disease appearing on Horses which live in the vicinity of poultry-yards and pigeon-houses, in its becoming very quickly generalized over all the body, and in its obduracy to all treat- ment until the Horses quit the locality, when it is readily cured. Besides the absence of the Sarcoptes, dermanyssic acariasis is also recognised by the small depilations it produces, which, though similar at first to those of sarcoptic scabies, become multiplied, but do not extend by a centrifugal development, like those of mange. It is difficult to mistake mange for phtliiriasis, as this only causes slight depilations, while the parasites are very visible ; and by the un- cleanliness which has permitted their multiplication, mange would have assumed quite another development than the slight lesions produced by the Lice. When fully developed, sarcoptic scabies looks like strangles eczema ACAEIASES. 145 (eczema rjoiirmeuse) and humid eczema {eczema dartreuse), but in the former there is no pruritus and it runs on rapidly to recovery ; whil c the latter, which is accompanied by the same kind of pruritus as mange, extends only slightly less rapid, becomes chronic, and assumes a lichenoid form ; though there is great difficulty in distinguishing it from sarcoptic scabies when microscopical investigations are without result. But the humid eczema is not contagious, and yields only to internal treatment, while external treatment alone will succeed with mange. Prognosis. — Sarcoptic scabies is the most serious of the three forms affecting the Horse. It owes its gravity to its great contagiousness — which allows it to assume an epizootic form — and also to its possible trans- mission to Man. In itself, it does not cause irreparable injury to the health of animals ; but by the debility and anaemia that ensue when it is of long duration, it predisposes to serious diseases which may ter- minate in death. It also causes great economic inconvenience and loss, as animals affected with it cannot be worked. With regard to its resist- ance to treatment, this varies according to the condition of the animals suffering from it and the duration of the disease. Young and vigor- ous Horses in good condition are less rapidly invaded by sarcoptic psoriasis, and are more easily cured, than are old, feeble, and worn-out animals. The disease is also more quickly combated when it is recent ; and it is rare that well-directed treatment does not succeed in curing it.^ Pathological Anatomy. — Besides the cutaneous alterations described when treating of the symptoms, dissection affords a more exact idea of the lesions accompanying the malady. Delafond and Bourguignon state that, if a fragment of the skin of a mangy horse be exposed to moist heat for 24 to 48 hours, the epidermis can then be removed by means of a fine scalpel and forceps. By a slight magnifying power and direct light, in the parts recently attacked can be seen the furrows or galleries, straight or sinuous, narrow and shallow, more or less near each other, and 2 mm. to 4 mm. in length. At various points they show widenings which are somewhat deeper than the other parts, where two or three eggs are deposited ; and at the end of a gallery is an ovigerous female. On the sides of the furrows the dermal papillae are red and hypertrophied, and the superficial layer of the derma is. infiltrated with a yellow serosity ; while in the vicinity of the galleries. (' My experience of sarcoptic scabies has been chiefly derived from army service during war, and 1 have found it a most formidable malady to contend with, and one causing somewliat heavy li ss, death often ensuing in a wonderfully short time. And even dtu-ing peace, it not unfrequfntly leads to a fatal termination when it ha.s been allowtd to go on. unchecked for a ctrtain period, and especially if the horses are old and weak, or over- worked and badly cared for. German authoiities also consider it a grave malady. For instance, Friedbcger and Frohner in their classical work — Lehrlmch der SitecuUtn PatliolO[/ie itnd Tlierapie der Hmidliiere — state that the prognosis is moie grave than is generally admitted, irnd that at an advanctd stage it is inveterate to all nifdication, even the most energetic ; that nearly alw»y.--, after months of treatment, lelapses occur ; and that in chronic cases more or less generalized, the animals become emaciuttd, fidl into a state of marasmus, and may perish from exhaustion.) 10 146 TREATISE ON PARASITIC DISEASES, — and even some distance from them — are vesicles, each formed by an elevation of the epidermis containing a little serum, the papillae beneath being exposed, and are red and infiltrated. Vertical sections will also show these lesions. At the points where the changes are not so recent, the galleries are distorted and disseminated, and the derma and papillae; are altered to a very high degree ; there are numerous elevations and depressions — for the Sarcoptes no longer live in the tunnels, but in depressions beneath the elevated and detached epidermis. All the derma is thickened by a sero-sanguinolent infiltration ; the lesions extend to the glands of the skin and the hair-folHcles, and this explains the shedding of the hair, the dryness of the crusts, and the thickness of the epidermis, the forma- tion of which is irregular. Lastly, in the parts where the disease is oldest, the skin is indurated and thickened, and all the secondary lesions are observed, depending on the cracks, erosions, etc., consecutive to the friction during life. There is nothing particular to note, either with regard to the engorgement of which the limbs may be particularly the seat, or of the internal complications which may occur in the disease (Delafond and Bour- guignon). Treatment. — On the first suspicion of mange, the suspected animal should be isolated. When there are several horses affected, it is well to divide them into categories, according to the period of treatment they have undergone. In the treatment — in addition to the destruction of the parasites — when the malady is of some duration, the general debility, the conse- quences of which are especially to be feared, has to be overcome. a. Treatment is to be commenced by clipping the patients, out of and at some distance from the stable. This clipping always shows that the malady is more extensive than was supposed, and is the only way of reach- ing all the parasites. (The hair should be carefully collected and burned.) h. The body is then subjected to a general lathering with soap and water in the following manner : Two to four pounds of soft soap are smeared over the surface of the body, and rubbed well into the skin, so as to cause it to penetrate the crusts. In an hour afterwards, the skin s scrubbed by means of a brush and tepid water (soft water if possible), and then tepid water is thrown over the body to remove all the soap ; the skin is dried by a scraper, followed by straw or hay wisps, which should, when done wdth, be burned (or buried in the dungheap). One lathering generally suffices, but another may be applied if crusts still remain. c. When the skin is dried, antipsoric remedies are had recourse to. Those which have fatty or oleaginous matters in their composition should not be applied over the whole surface of the body at one time, in order to avoid sudden suppression of the cutaneous functions. When J ACAKIASES. 147 the scabies is generalized, the dressing should be applied over one half of the body at a time — right or left side, or anterior or posterior moiety — an interval of forty-eight hours being allowed to elapse between the two applications, and then another general lathering after the same period. Petroleum and benzine are often used, and they are excellent acaricides ; but they have the inconvenience of producing irritation of the skin, which continues for a long time, prevents the practitioner easily ascertaining if the disease is cured, and hinders the employment of the animals immediately after recovery. So that there is reason to reject them in practice. In Germany creosote is very much employed, the experiments of Gerlach having demonstrated that it is at the head of all the acaricides, as it causes the death of the Sarcoptes in 15 to 45 seconds. It is used mixed with alcohol and water (creosote and alcohol 10 parts, water 25 parts), or with oil (creosote 1 part, oil 25 to 40 parts), or lard (same proportions). The liquid form is the best. One to three energetic applications at intervals of three to five days, suffice to effect a cure. In France, the agents which succeed most rapidly are found to be tobacco, sulphurated potash, and sulphur. The liquid refuse of tobacco manufactories, in the proportion of 2 ounces to 1 pound of oil, constitutes an efficacious and economical preparation. When a manufactory is not near, and this refuse cannot be procured, tobacco itself must be dispensed with, as it is too costly. Sulphurated potash in concentrated solution, 9 ounces to the quart of water, acts efficaciously, and is very frequently employed. The Codex gives the following formula, under the heading' Sulp'iurous Pomade for the Cure of Mange (Trasbot) ' : Solid trisulphuret of potassium - - - - - 10 parts. Carbonate of potass - - - - - - 2 „ Lard -.-..... 300 „ Mix thoroughly. This is destined to replace the pomade of Helmerich. Sulphur is used in the form of a sulphur pomade (sublimed sul- phur 10, lard 30 parts), or Helmerich's pomade (sublimed sulphur 200, potassium carbonate 100, lard 800 parts). Numerous formulae have been given for the antipsoric employment of sulphur ; but the two preceding, and especially the pomade of Helmerich, are those which merit the preference. The Codex gives the following formula for a mange-dressing : Benzine --....-- 300 parts. Oil of tar ....... 100 „ Coal-tar ■ - - - - - - - 100 „ Soft soap ....... 100 ,, Oil of turpentine - - - - - - 100 ,, Triturate the soft soap and coal-tar in a mortar, and add the oi! of tar ; the mixture being perfectly homogeneuus, gradually incorporate the oil of turpentine, tlien the benzine. 10—2 148 TREATISE ON PARASITIC DISEASES. In employing these different remedies, the entire surface of the body sliould be dressed at one time ; nevertheless, in using the tobacco there is danger of poisoning, and it is safer to dress only one-half of the body at a time. The preparations of sulphurated potash or sulphur have not this inconvenience, and they are cheap. The medicament is allowed to I'emain on the skin for three or four days ; and then a last washing with soap is made in the same manner as the first. When the medicinal rubbing has been well done, and no part of the body has been overlooked, it is rare to see the itching persist. A most careful repetition of the treatment will most certainly triumph over the disease. At the Toulouse Veterinary School, the treatment successfully employed consists in the use of a pomade named ccvndillc oil, prepared according to the following formula, which is almost that of Pujol and Bonnet : Powder of cevadilla (Asagnea officinalis) - - - 4 ounces. Ca'cined alum - - - - - - - H „ Sublimed sulphur - - - - - - 2 ,, Olive-oil - - - - - - - - 1 quart. Digest for two hours in a water-bath. In the case of localized mange, the oil of tar is sometimes employed. For some time, creoline or cresyl has been successfully used in solution, 10 to 15 per cent. ; and it is as simple as it is inexpensive. To prevent the reappearance of the disease, it is obvious that disinfection of the harness, clothing, grooming utensils, and stable is necessary. The best disinfectant is boiling water, the Acarina and their eggs being destroyed at a temperature of 70° to 80° (Cent.). If there is apprehension that this may spoil the harness, it can be disinfected by plunging it into an antipsoric solution of sulphurated potash or creoline. Internal treatment, which played so large a part in the older medicine, should only have for its object remedying the constitutional debility. Abundance of food, tonics, and good general hygiene are the simple means to be resorted to. (This treatment of sarcoptic scabies does not differ much from that resorted to in England, "When the skin has been thoroughly washed with soap and water as recommended above, it is soaked for some time with a solution of pot. carbonate and oil, and the parasiticide is then rubbed in, a second dressing being made in about a week. Washing with lead acetate solution relieves the eczema that frequently accom- panies mange, while diluted alkaline solutions and oil of eucalyptus abate psoriasis. Chronic inflammatory sequelae are treated by weak solutions of Goulard's lotion, glycerin and water ; with salines, arsenic, and iron salts internally.^) Sanitary Police. — Sarcoptic scabies of the Horse is not comprised (• Finlay Dun. Veterinary Medicino^, their Actions and Uses, 1889.) ACAKIASES. 149 in the list of contagious diseases dealt with in the (French) law of July 21, 1881, on the sanitary police of animals. But because of the serious outbreaks which occur in the army, it is the object of special measures to be now referred to. These measures are prescribed in article 10 of the decree of December 26, 1876, with regard to the regulations for the veterinary service of the army ; article 79 of the decree of December, 1883, bears upon the internal service of troops of horse, and by the notes B and D annexed to this decree — When a Horse is recognised as affected with mange, it is immediately removed from the ranks, and isolated in a special stable, which ought not to be occupied by any healthy Horses, or those suffering from any other disease. It is attended to every day by the same soldier, who leaves his grooming articles in the stable ; it should not be taken to the general water-troughs, and exercise ought to be given in a place apart from that to which other Horses are taken. Its harness, clothing, and grooming equipment are to be taken charge of by the veterinary surgeon, who keeps them in a special place, and does not allow them to be issued until they are disinfected. The two Horses which stood on each side of the affected one are con- sidered suspected, and are to be kept in a special stable, if possible; if this cannot be done, then they must be moved to the end stalls of their stable and carefully watched ; the veterinary surgeon visiting them every day, and keeping them under observation for ten days. The three stalls rendered vacant by the removal of these Horses must be disinfected, the veterinary surgeon directing this operation. When mange prevails in a regiment, and, because of the number of Horses attacked, it assumes an epizootic character, the veterinary surgeon should exercise a minute watchfulness over all of them. Every day he will attend stables and successively examine the Horses, paving particular attention to the mane, root of the tail, and the inner surface of the limbs ; he will also advise the officers — commissioned and non- commissioned — to report any Horses which rub themselves. In this situation, every Horse which shows depilations and exhibits the slightest signs of itching should be considered suspected, removed from the ranks and isolated, its stall being cleansed and disinfected. Two stables at least should be placed at the disposal of the veterinary service— one for the Horses affected with mange before their treatment, where they will be clipped and dressed ; the other for the reception of the Horses immediately after the application of the antipsoric remedy, and where they will remain until they are cured. No matter how much or how little a Horse may be affected, it should be clipped and dressed all over the body. The most certain and simplest treatment to employ in these circum- stances is the mixture of equal parts of petroleum, benzine and oil of earth-nut (arachis hjipogea). It is merely applied to the skin without friction, and its irritant action may of course be diminishied by increasing the proportion of oil. The hair which has been removed should be gathered into a corner of the stable, well wetted with a 1 per cent, solution of carbolic acid, then removed to a distant place and deeply buried. After the Horses are cured, they are placed under observation in the infirmary stables — or a special stable if there is one disposable, and they 150 TREATISE ON PARASITIC DISEASES. should not be sent to duty until all traces of the disease and treatment have disappeared — that is, when the skin has regained its suppleness, and the hair has begun to grow everywhere. A Ministerial circular of January 6, 1872, states that no Horse suspected of, or affected with a contagious disease, is to go on the line of march. In armies on a campaign, Horses affected with, or suspected of con- tagious diseases are to be immediately separated from the others, and the authorities of the localities in which they are halted are to be informed of the malady. Horses affected with mange are to be sent — with all their equipment — to special depots, which are to be established only for Horses suffering from diseases of this kind, in farms or villages outside the lines of communication and marching routes. Horses which are cured will not leave these depots to join their corps until all traces of the disease and of treatment are effaced, and their equipment has been thoroughly and completely disinfected. Note B indicates the means of disinfection to employ in cases of contagious disease. 1. Disinfection of Stables and their Contents. — "Whether it concerns an entire stable, or only a portion of it which has been occupied by mangy or suspected Horses, the litter should be carefully removed therefrom and deeply buried in the manure-heap. Then the interstices in the floor, internal surface of the walls, mangers, and hay-racks should be scraped and thoroughly cleansed. A general washing with water as hot as possible, must be done immediately afterwards, in order to remove all the dirt that the scraping has left. This operation must be followed, a few hours later, by a washing of chloride of lime— 1 pound to 120 gallons of water. Next day the walls, mangers, racks, etc., are to be whitewashed with lime, which is also to be spread over the floor. If the latter is macadamized or laid in concrete, it is necessary to scrape it well, and even to repick it, according to its state of preservation. If the whole of the stable has been disinfected, the windows and doors should be opened in order to dissipate the damp. The stables or places so disinfected should not be reoccupied within eight to ten days. With regard to the articles in the stable — such as the bales, corn- chests, forks, shovels, buckets, troughs, etc., they should also be scraped, well washed with water and afterwards with chloride of lime, and allowed to dry before being used again. 2. Disinfection of Equipment. — The bridles, bridoons, and head-collars should be taken to pieces, and the accessories removed from the saddle. All the parts of leather or hide, thus separated, are to be washed one by one, and repeatedly, with a hard brush, and frequently dipped in a solution of chloride of lime (1 pound in a bucket containing 2 gallons of water). Those parts which have been immediately in contact with the animal's body should receive particular attention. As each article is washed with the lessive, it is thrown into a bucket of water, from which it is taken, dried, and dressed with neat's-foot oil. The parts which are not to be oiled should be dried in the shade. Those parts which are of cloth or linen, as well as iron articles — bridle-bits, curb-chains, stirrups, rugs, surcingles, etc. — arc steeped for three or four minutes in boiling water. As a rule, all articles that will not be damaged thereby should be disinfected by a few minutes' immersion in boiling water ; otherwise, ACABIASES. 151 they ought to be lessived in chlorinated water and immediately after washed in clean water. Those parts of the saddle which cannot be disinfected — such as the pannels, etc. — should be replaced. 3, Disinfection of Mens Effects and Grooming Kit. — The combs and brushes of the men who attend to these Horses, and the clothes they wear, should be passed through boiling water. The grooming tools used on mangy Horses ought to be disinfected by a few minutes' immersion in boiling water. 2. Psoro2)tic Scabies. Synonyms. — The Bouvicux of the hippiatrists ; the Gale humicle of La Gueriuiere ; the Gale par acare of Huzard, jun. ; the Gale clermato- dectiqice of Delafond. This form of scabies has been the longest known, and is the most common. It affects the Horse, Ass, and Mule, and sometimes prevails epizootically. According to Delafond and Bourguignon — who have thrown much light on the history of this malady — like the majority of the forms of psora, the parasite of this form (Psoroptes communis, var. equi) was observed about the middle of the last century by Lonting ; but the first illustration of it vv'as by Gohier and Saint-Didier, and was presented to the Agricultural Society of Lyons in 1813 ; then came the drawings of it by I3osc in 181G, in the Dictionnairc des Sciences Mklicales ; after- wards those of Easpail in 1833, of Hertwig and Hering in 1835, of Gervais in 1841, of Dujardin in 1848, and of Gerlach in 1857. Symptoms. — Psoroptic scabies of the Horse may appear on any part of the body except the extremity of the limbs ; but it more especially affects the upper part of the neck— at the root of the mane— the poll, and the tail ; and as it immediately givesjises to pruritus, attention is often directed at first to the state of the long hairs, which are mixed and rubbed. The pruritus has the same characters as that of sarcoptic scabies. The first alteration noticed is in the form of small papules — which are red on the non-pigmented parts of the skin — from 7 mm. to 8 mm. in diameter, and 2 mm. to 3 mm. high. At their summit the epidermis on these papules is raised by an accumulation of serosity, which quickly causes it to be broken, and from this results a crust, owing to the dessi- cation of the fluid ; but as this continues to exude, the crust becomes thicker in mixing with the epithelial debris, and remains moist and viscid— a feature that distinguishes it from the always dry and fur- furaceous crust of sarcoptic scabies. As each vesico-pustule is the result of the puncture of a Psoropt, and as the parasites live in agglomerated colonies on the surface of the epidermis, these punctures are made near each other and become multiplied as the Psoroptes increase in numbers, until at last they are confluent, and form veritable plates of crusts. 152 TREATISE ON PARASITIC DISEASES. The rubbings that the patient energetically practises against every- thing within reach, contribute to the inflammation of the skin, to the abundance of crusts, and to the formation of sores and ulcers. The crusts themselves — which are naturally of a light-yellow tint — are often red or dark-coloured, from the blood impregnating them. The hairs become uprooted, and fall off during the rubbing or grooming, leaving a smooth, shining, greasy patch. The skin is infiltrated, thickened, and hard, as well as wrinkled where the subjacent connective tissue will permit it to be so. The crusts are agglutinated together, and become more and more abundant, adhering more or less closely to the surface of the derma. Contrary to what occurs with the Sarcopt, the Psoropt seeks the parts sheltered by the long hairs, notwithstanding the thickness of the skin at the parts. The progress of the troubles that it excites are more important, owing more to the increasing gravity of the local alterations, than because of the rapidity of extension of the disease. A large super- ficies of skin may still remain intact, while serious changes are accumu- lating in a short time around the primary point of invasion. The regions in which the disease remains at first for a long time localized, are the forelock, mane, and base of the tail ; then it extends to the submaxillary space, the breast, and the internal surface of the thighs and neighbourhood of the prepuce. It increases by a regular extension, the limits of the patches incessantly growing, but not in the diffuse manner seen in sarcoptic scabies. It may be transplanted by grooming to any part of the body, but its extension is always centrifugal. The upper part (or ridge) of the neck affected with sarcoptic scabies is thickened, infiltrated, marked by large transverse folds, partially depilated, or covered by very short hairs mixed with some long ones ; while crusts are extended over them, and in the deep furrows between these folds exudes an abundance of viscid, often foBtid serosity, that, in summer, may contain the larvae of Muscidae. This localization of the disease has received the name (in France) of Bouvieux. The presence of the Psoroptes gives to all the symptoms their precise significance. They are always in great numbers at the points invaded, and are readily found beneath the crusts, especially towards the limits of the patches. In examining scrapings from these parts on black paper, by means of a magnifying-glass, or even with the unaided eye, numerous Psoroptes will be seen moving about actively, in all phases of development, and often in a state of copulation (Figs. 63, 73, Ti, 75, 76). Course, Duration, and Termination. — Sarcoptic scabies progresses slowly, and very rarely invades the whole surface of the body. While at the end of a month the Sarcoptes will have spread to the most distant parts of the skin, the Psoroptes at this time will be still located at the upper part of the neck or base of the tail, where they had ACARIASES. 153 established their first colony. No fixed duration can be assigned to this form of scabies, even approximately ; but in any case it has no tendency towards a spontaneous cure. If it is admitted that it could cause death by marasmus when it becomes absolutely generalized, instances might be given of Horses allowed by their owners to fall into this miserable condition. Etiology, Contagion. — It has been already mentioned (p. 118) that of the three kinds of psoric Acarina, the Psoroptes are those which secrete the most acrid fluid, and this explains the intensity of their morbid effects. Psoroptic scabies, like the other forms, can only be developed by contagion ; so that there is no occasion to take predis- position into account ; and uncleanliness, from whatever cause, can alone play a preparatory part. Contagion is effected in the same extrinsic conditions as in sarcoptic scabies ; it is as much more active as the contagiferous animal is seriously affected. "With regard to the persistency of contagion in articles coming from mangy Horses, the experiments of Gerlach have shown that the vital resistance of the Psoropt exceeds that of the Sarcopt. Eemoved from its host, it lived from ten to fourteen days in a dry atmosphere, and from twenty to thirty in a stable. Plunged into a state of apparent death, it may yet at the end of six to eight weeks be revived by means of heat and humidity, though it will not recover so much as to be able to puncture the skin. Fecundated females have a greater vital resistance than the males, and the latter than non- fecundated females. The majority of the experiments appears to demonstrate that it is always from the Horse that the Horse receives the original Psoropt that invades it. Gohier vainly endeavoured to transmit the scabies of the Ox to Horses and Asses, and Delafond also failed with the Psoroptes of the Sheep conveyed to the Horse. Nevertheless, if Hosseus has un- successfully attempted to transmit the Psoroptes from the ear of the Eabbit to Horses, Mathieu has, in the same conditions, obtained a positive result. On the other hand, facts given by Cagny and by Cadeac would lead to the belief that, in some circumstances, the psoroptic scabies of the Horse may have its origin in the auricular acariasis of the Eabbit (see Parasitic Diseases of the Ear). When placed on the skin of Man, the Psoroptes cause a violent pruritus ; but they never give rise to a psoric eruption , and soon disappear. Gerlach could not succeed in transmitting the psoroptic scabies of the Horse to the Sheep and Ox ; and Delafond also failed with the latter animal, notwithstanding the apparent identity of the Psoroptes that the Horse and Sheep may harbour. Experiments of transmission made with the Pig, Dog, and Cat have always given a negative result. Diagnosis. — What has been said with respect to the symptoms of 154 TRKATISE ON PARASITIC DISEASES. sarcoptic and psoroptic scabies, and the resemblance that has been spoken of when alluding to the differential diagnosis of the former, will enable us to dispense with further reference to this point. The differ- ence between this form and symbiotic scabies has also been sufficiently indicated (p. 129). The usual readiness with which the parasite can be found renders diagnosis easy. At the commencenient of the affection, its presence may be demonstrated in fixing the crust on the arm of a Man ; in one or two hours afterwards a pricking sensation will be experienced in the part, due to the punctures of the Insect. It should always be remembered that the three forms of scabies may co-exist on a Horse, although simultaneousness of two of the types is absolutely rare. Psoroptic scabies may also be mistaken for pityriasis — the principal form of the Ronvieux of the hippiatrists — and which often affects the upper border of the neck and root of the tail of dirty horses ; it also often coincides with phthiriasis, of which it is then only a mani- festation. And, besides, it may be distinguished from psoroptic scabies by its chronicity, its slight tendency to extend, the trifling pruritus, and, above all, by the absence of the Psoroptes. Prognosis. — Psoroptic scabies is a much less serious affection than sarcoptic scabies. Its extension is less rapid, it is much longer localized, is not so frequently epizootic, is much more easily combated, and rapidly yields to proper treatment. The skin often retains, for an indefinite time after the disease has been cured, the morbid thickness it had acquired, and many of the hairs are not reproduced. Pathological Anatomy. — There is nothing particular in the descrip- tion given by Delafond and Bourguignon of the morbid lesions of the psoroptic scabies of the Horse ; it applies to all the irritations of the skin, and is subordinate to the intensity of these. Treatment.— The same prophylactic, hygienic, and therapeutic measures are necessary for this form of scabies as for the sarcoptic form. Failure is rare, and the treatment may even be more simple, as it can be limited to the affected parts, or be only extended for a little distance on the healthy skin surrounding these ; while, in order not to disfigure the animal, portions of the hair of the mane and tail can be allowed to remain. On the neck, only the hair in the furrows of the skin is removed with scissors, that on the summit of the ridges being left. At the tail, transverse cuts are made through the hairs, so as to leave wide lines on the most affected places ; these will allow the air to circulate more readily among the hairs, and so to dry the crusts, rendering cleansing and the application of remedies more easy. With respect to remedies, these, from motives of economy and in view of limited employment, should have vegetable tar as their base ; though this does not answer for sarcoptic scabies, in which, the applica- tion being of necessity general, the animal would be exposed the ACAEIASES. 155 danger of cutaneous asphyxia. This tar is generally mixed warm with soft soap (2 parts of the first to 1 of the second), and it is rubbed into the patches on the skin by means of a brush, without making the appU- cation general. This remedy has the inconvenience of soiling the skin, but the same objection applies to the cade-oil.^ It is only used for common Horses, and, in general, recourse is had to one or other of the remedies indicated for sarcoptic scabies. 3. Symbiotic Scabies. This form of scabies — the Gale du pied (of the French), the Fussrdude of Gerlach — was first described by Gerlach in 1857, and was subse- quently studied by Delafond and Bourguignon. It is due to the common Symbiot (Figs. 77, 78, 79). Symptoms. — The disease commences at the fetlocks and pasterns — chiefly those of the posterior limbs. It afterwards reaches the shanks, hocks, and knees, rarely extending to the body or croup. It is indi- cated by signs of itching, which are much less active than in the two preceding forms, and are more particularly noticeable during the night, and while resting after work. The Horse stamps, rubs one leg against he other, endeavours to bite the limbs, and kicks. (Such horses are very troublesome to shoe, as they try to rub the aflected leg while the sheer is holding it up, and therefore he is much pulled about.) In a variable time — sometimes several months — the region affected is covered by an abundant epidermic desquamation, in the midst of which the Symbiotes are readily discovered ; the hairs are shed, and in the parts Hmiting the depilations they can easily be pulled out in tufts, leaving the subjacent skin bare and smooth. At a later period, the skin becomes thickened and exudes ; crusts of variable thickness form, and cracks appear in the hollow of the pastern, which may granulate and become somewhat serious. (Coarse-bred, heavy Horses are generally those most liable to become affected, the thick hairy legs affording good shelter for the parasite. The skin is scurfy and the hair much broken and woolly.) Symbiotic scabies follows an extremely slow course, and a Horse must be greatly neglected by its owner, even for several years, before the disease invades the upper part of the limbs and the trunk. It shows itself almost exclusively during the winter — not that the Sym- biotes abandon their host during the summer, but probably because, during this season, the natural excretions of the skin dispense with the necessity for actively pricking it, in order to excite the exudation of nutritive fluid. The disease may persist for several years if the Horses are badly (^ This cade-oil— 0^e«m Cadimum, or Pii/^e^ceum — is much employed in France and Germany. Ic la the aromatic tarry oil obtained by the dry distillation of the wood of Juniperus Oi:yctdi u-s.) 156 TREATISK ON PAKASITIC DISEASES. groomed. The skiu then becomes infiltrated, and cracks more or less deeply in the hollow of the pastern and above the fetlock ; in the course of time the papillic of the derma become hypertrophied, and this is shown by round or conical prominences close together, and covered by a smooth and shining epidermic layer. These increase in volume ; and in the furrows between them appears a foetid, sero-purulent matter, chiefly composed of serosity and a mass of epidermic cells. In this product, the Symbiotes of all ages — males and females — are found in considerable numbers, as well as their eggs, the debris of their moultings, and their excrements. Etiolog"y, Contagion. — Symbiotic scabies is never seen in well-bred Horses, because of the orderly way in which they are kept, and the fineness of the hair on their legs. It is the appanage of common Horses, which have coarse long hairs on their limbs, and the skin is always dirty. This is the reason why it is most frequently seen on young Horses which, not yet at work, ai-e not regularly groomed ; as well as on old worn-out animals which have fallen into cai-eless hands, and which are near their final stage— the knacker's estabUshment. Contagion is effected by grooming articles, but more especially by litter, in which the Symbiotes may live for a long time. Gerlach has kept them with cinists in a warm place, and at the end of ten to twelve days they appeared to be dead ; but heat and moisture rendered them active in fourteen days. In the spring, or in a place not warm, they have succumbed in fourteen days, and in fifteen in a stable. Delafond and Bourguignon have kept them alive from sixty to sixty-five days, in boxes placed in a stable, with a temperature of 14° to 15° Cent. (57-2" to 59° Fahr.), care being taken to renew the air in the box and to main- tain a proper amount of humidity. The disease owes its extension to transmission from diseased to healthy Horses. The Symbiot of the Ox conveyed to the Horse, dis- appears without attacking the skiu ; while that of the Horse transplanted to Man, and other creatures than the equine species, has produced no results. Symbiotic scabies is the least contagious of the three forms of equine scabies, as the Symbiot has little tendency to emigrate, often remaining localized on one limb, or on two anterior or posterior limbs. Gerard and Eailliet completely failed in their well-conducted attempts to develop the disease on Horses, by depositing the parasites in the hollow of the pasterns. It is true that they experimented with old horses ; and Eailliet is inclined to believe that the disease is proper to young Horses, the cases recorded as occurring among old Horses being due to the persistence of the malady from their earlier years. ^ Diagnosis. — With regard to this, there is nothing to be added to ' J. Gerard. Recueilde M^d. Vet^rinaire, 1871, p. 402. — Railliet. Socic^te Centr. de Med. Vet(irinairo. Reciieil de Mi^d. Vet^rinaire, 1879, p. 222. ACAEIASES. 157 what has been already said concerning sarcoj^tic and i^soroptic scabies. The markedly special seat of symbiotic scabies, its symptoms, and the facihty with which the parasites are always found, should prevent mis- takes, and particularly if it be remembered that the simultaneousness of the two forms of scabies is possible. Prognosis. — This disease — the most benignant of the psor^ of the Horse — only persists when the horse-owner allows it to do so ; as it is most easily got rid of, and is only serious when complicated with cracks in the skin and papillary growths, which, after they have been cured, often leave thick cicatrices. Treatment. — To prevent the somewhat inactive contagion of sym- biotic scabies, it is well to isolate the affected Horse, or, at least, to often renew its litter and look well to grooming, for cleanliness is always one of the most efficacious of the curative agents. The hair should be removed as close as possible from the invaded regions, and even a little beyond them ; then the brush or wisp will remove, along with the crusts and scurf, quantities of parasites and ova. The whole of the affected parts are then to be well rubbed with soft soap, which should be allowed to remain on for about twenty minutes, when it is to be washed off with warm water, and the skin treated with the scraper and well dried. The antipsoric medication properly prescribed by Delafond and Bourguignon, consists of friction either with a concentrated decoction of tobacco, the pomade of Helmerich, or — which is more expeditious benzine or oil of turpentine. One, two, or at most three, rubbings with one or other of these agents suffices to completely cure the disease. At the Toulouse Veterinary School, a mixture of equal parts of oil of petro- leum and Hnseed-oil are employed. A mixture of Stockholm tar or cade- oil with an equal part of soft soap, applied warm over the whole of the affected surface, gives excellent results when the disease is chronic ; but when it is accompanied by hypertrophy of the papilla, then there should be applied, and more than once, the mixture of tar and soft soap, to which should be added 1 to 2 drams of finely-powdered arsenious acid to every pound of the mixture. B.— Scabies of Bovine Animals. It had been known for a long time that bovine creatures might be affected with psora, as Delafond and Bourguignon state that it is men- tioned in the writings of Columella, who lived in the first century of our era, and also in those of Vegetius. Since the establishment of veterinary schools, bovine scabies has been frequently observed, and its parasitic nature has been clearly recognised. It might appear at first sight that the Ox, like the Horse, should be affected with the three forms of scabies, of which the pathogenic agent is a Sarcopt, a Psoropt, and a Symbiot. 168 TKEATISE ON PARASITIC DISEASES. 1. S arc op tic Scabies. Sarcoptic scabies of the Ox is only incidentally mentioned here, as its history is limited to the possibility of its existence. Grognier, indeed, mentions that the mangy Horse alluded to at p. 142 communicated its disease not only to several people, but also to two Cows placed along- side it in the stable. The transmission to Man demonstrated the sarcoptic nature of the affection. It was the same with the case recorded by Eobert Fauvet : the mangy horse sold to a miller infected a Cow that had rubbed its neck against the manger, Wallraff has reported the history of an epizooty of mange that pre- vailed among Goats in the valley of Prilttigau, Canton of Grisons. The disease was communicated to Man, and was therefore sarcoptic ; it was transmitted to cattle and Horses.^ Delafond produced a fugaceous form of mange that disappeared spontaneously, in depositing some Sarcoptes from a diseased Dog on the skin of a Bull and a Calf. These are all the facts that are known of the sarcoptic scabies of the Ox. Kademacher^ relates that a mangy Cat, which was in the habit of resting on the back of a Cow, infected the latter ; the Cow gave the disease to a servant, and she, in her turn, gave it to all the family. It will be shown hereafter that the scabies of the Cat can be conveyed to Man ; but as it is due to the Sarcoptes minor, and not to *S'. scahici, the instance given by Eademacher cannot be accepted as of equal value — so far as the history of bovine sarcoptic scabies is concerned — with that of equine scabies, due to the S. scabici. For the same reason, the incom- plete, and even inexact, observation of Thudichum,-' relative to the development of scabies in people who had been in contact with a mangy Cow, cannot be utilized. 2. Psoroptic Scabies. Synonyms. — Dcrmatocoptic scabies Roll ; Gale dermatodectique Delafond. History.* — According to Sauvages, Linnajus observed on cattle a mange that was caused and maintained by insects, which were found located in the tubercles of the skin ; but, in reality, the first mention of a parasite — in 1813 — is due to Dorfeuille, a veterin-ary surgeon at Port- Sainte-Marie (Lot-et-Garonne, France^, who reported his discovery to Gohier, who, in the following year, found this acarus on the Hungarian cattle which the Austrians brought in large numbers with their army to Lyons. Gohier did not remark any difference between this animal- cule and that which he had seen — the Psoroptcs communis — in a form of mange of the Horse. After long search, Delafond in 1856 discovered this parasite on English and Limousin cattle, at the same time that Gerlach did on mangy cattle at Bromberg.^ This form of scabies was 1 Wallraff. Repertorium der Thierheilkunde, 18.'J3. ■•^ Rademacher. Magazia fiir Thierheilkunde, 1842. Cited by Delafond and Bour- guignon. ^ Thudichum. lUustr. med. Zeitung de Rubner, 1852 ; and Ann. de Med. V^t^ri- naire. Brussels, 1854, p. 327. * Sauvages. Nosologic Methodique. Gouvion's translation, Paris, 1772, IX., p. 439. —Gohier. AI6m. et Observ. sur la Chir. et la MM.. Veler., I., 1813, p. 10; II., 1815, p. 123. — Gerlach. Krdtze nnd Jiiiude, Berlin, 1857. — Midler. Magaz. fiir die gesamuite Thierheilkunde, XXVI., 1860, p. 90. (* For an account of the German discovery of this parasite by Gerlach and Miiller, see my work on 'Veterinary Sanitary Science and Police," 1875, II., p. 427.) ACAKIASES. 159 again seen by Miiller in 1860, and since that time it has been observed at intervals on French cattle. (The disease is not uncommon in the United Kingdom.) Symptoms.— The psoroptic scabies of the Ox has great analogies with the same form in the Horse. It commences at the root of the tail or — though less frequently — at the neck or v^^ithers, and gradually extends to the head, back, shoulders, sides of the chest, and finally invades the entire surface of the body, except the limbs. There is violent pruritus : the animal scratches and rubs itself in every possible way, and often causes blood to flow from the affected parts. An attentive examination discovers — at the place where the disease commences — small, miliary, epidermic elevations, discrete or confluent, filled with serosity. This escapes, agglutinates the hairs, dries, and gives rise to very adherent crusts, which increase in number and extent. There are soon seen on the skin numerous patches of mange — depilated, borders irregularly festooned, covered with thick, grayish, scaly or lamellar crusts. Beneath and between these crusts the Psorptes multiply. They can be readily seen by the naked eye, or by means of a lens, in spreading skin-scrapings on black paper in a warm place. The skin itself, when freed from crusts, is seen to be depilated, thickened, hard, dry, and cracked, with thick folds on the sides of the neck, shoulders, and chest. In serious and neglected cases ulceration may ensue, due more especially to the continual rubbing. The animals then fall into a state of extreme cachexia ; the superficial lymphatic glands in the adjacent regions are hard and prominent, but not painful ; and death is the sequel to this miserable condition. Gerlach and Miiller have remarked on the modifications occurring in this form of scabies by change of season. On a farm in the circle of Inowraclaw, the disease prevailed among the cattle every year, com- mencing towards the end of autumn when the animals began to be housed, reaching its maximum in February, and diminishing in spring, when the Oxen were employed at labour ; the crusts then became detached, the hairs grew, and there only remained a few bare patches at the root of the tail and on the neck, while around the horns and on the neck epidermic scales were abundant. The train of symptoms reappeared each autumn. Gerlach and Miiller recognised that the Psoroptes persisted in summer, although the Oxen appeared to be cured ; the parasites were in great numbers on the neck and around the horns, and Symbiotes were mixed with them. It would appear from these facts, that the residence of the Oxen in warm stables during the winter favours the development of the parasites. Etiology, Contagfion. — The immediate cause of this scabies is the Psoroptes communis, var. bovis. Conveyed to healthy animals, it 160 TREATISE ON PARASITIC DISEASES. develops the same disease on them. It may, nevertheless, be admitted that poverty and uncleanliness are predisposing causes ; and it has been shown that dwelling in a stable during winter favours the development of this malady, while living in the open air during the summer does not. May the Ox contract the psoroptic scabies of other domesticated animals with which it comes in contact ? Gohier and Carrere^ have reported affirmative facts, in which Cows have acquired the disease after being — for a variable period — beside a mangy horse. But they have not given details as to the characters of this psora, either on the Horse or the Cows ; so that it is impossible to give an opinion as to whether it was this, or one of the other forms of scabies. The experi- ments with regard to the transmission of psoroptic scabies from the Horse to the Ox, made by Gerlach, and more especially by Delafond, carried out under the most satisfactory conditions, have always yielded negative results — ^Delafond only once having observed a fugitive pruritus that was not followed by scabies. And it is also the fact, as demon- strated by the experiments of Delafond, that the Psorpt of the Sheep cannot be acclimatized on the Ox. Only on two occasions in five did the transplanted parasites attack the skin of the calves experimented upon — thin crusts were formed, but the Psoroptes died or disappeared in from three to six days. Inversely, attempts at transmission of the psoroptic scabies of the Ox to the Horse were without result in the hands of Gohier and of Miiller. Diagnosis. — The psoroptic scabies of the Ox might, in one of its phases, be mistaken for certain cutaneous affections which somewhat resemble it. But the error may be averted by a careful examination, which will decide whether or not the Psoroptes — so easily found and distinguished from every other parasite — is present. The j^htliiriasis due to the Ilccmatopinus cur ystcrnus or II. tenuirostris — which are very pruriginous, cause depilations, and locate themselves on the upper part of the neck and withers — is easily recognised by the presence of the Lice ; but as it may coincide with scabies, something more than a superficial examination is necessary. However, the treat- ment usually employed against the parasitic Insects will destroy Acarina. The i)niriiio that results from heating food, or the transition from a poor rdgivie to an abundant ration — and which also often appears with- out any appreciable cause— may extend to various parts of the body or be limited to some. It is characterized by discrete papules — which may be small and soft, or voluminous and hard — that cause a violent pruritus, particularly when the body is heated. In consequence of rubbing, the excoriated papules are covered with blood-tinted crusts, J (Tohier. Compte Rendu de I'^cole de Lyon, 1817. — Carrfere. Journal des Vet^r. du Midi, 1838, p. 241. ACARIASES. 161 and the skin is thickened, chafed, moist, and depilated in patches. This disease may quickly subside spontaneously, but it may also continue for months. It has a great resemblance to scabies, and especially when it manifests itself on several animals at the same time in one place ; then contagion might be suspected. The diagnosis will be decided by the absence of acari, and by the utility of internal treatment — alteratives, purgative salines, arsenious acid, etc. In tinea tonsurans — which is contagious, hke scabies — the patches invaded by the Tricliophyton are always circular, and have limited dimensions — from 3 cm. to 5 cm. in diameter ; while those of scabies are irregular, and have a disposition to extend along the body. Besides, each of these two affections has its own proper parasite, the presence of which fixes the diagnosis. Prognosis. — Psoroptic scabies in the Ox can only become serious when it has been absolutely neglected, and the cachexia accompanying it has become chronic ; for it readily yields to various antipsoric remedies. Pathological Anatomy. — G. P. Piana^ has given the following resume of his researches into the lesions of the psoroptic scabies of the Ox. The Psoroptes induce very limited exudative inflammation in the regions of the derma corresponding to the points where they insert their mandibles in the epidermis ; the exudate resulting from each of these inflammations is infiltrated between the cells of the rete muco- sum, and also collects in the substance of the epidermis itself. This exudation is very rich in leucocytes, which, owing to their sarcodic movements, become insinuated — along with the fluid portion — between the deeper epidermic cells. Consecutive to these changes, and according to the intensity of the dermal inflammation, the alterations may assume two different aspects. In the first, the formation of the exudate ceases, and new epidermic layers are established beneath the ah-eady developed exudative masses, which fall off afterwards with the epidermic scales. In the other case, the exudation continues, and the product already accumulated in the substance of the epidermis continues, until it causes rupture of the horny layer, and complete destruction of the rete mucosum — hence more marked irritation and the possible formation of a veritable ulcer. When the punctures of the Psoroptes are confluent, instead of small and distinct inflammatory points, a very extensive exudate is thrown out, which, in drying, forms a crust. Treatment. — The curative measures indicated for the psoroptic scabies of the Horse are in every way applicable to the same form of psora in the Ox. Mercurial preparations should on no account be ^ G. P. Plana. Jiicerche sidle hnioni istolo'jinche .... iiella pdle del Bue per la Roijna dermatodectka. Giorn. di Anat. Fisiol. e Patologia, Pisa, 1878, p. 287. 11 162 TREATISE ON PARASITIC DISEASES. employed, as they may be absorbed and cause more or less serious poisoning; for cattle are particularly liable to hydrargyism, and numerous instances are recorded to prove the danger incurred from the use of these preparations. These dangers are due, for the most part, to the great tendency of the larger ruminants to lick themselves, and especially whenever they experience any itching sensation. In ad- dition to thej mercuriaP preparations, all toxic substances — such as cantharides, arsenic, etc. — likely to create another disease than that to be combated, should be absolutely proscribed. 3. Symbiotic Scabies. Synonyms, History. — Dcrmatoj^hagic scabies Eoll, Chorioptic scabies Megnin. This form of scabies is very rare in France, but it has been particularly studied in Germany. According to Gerlach, the first mention of the acarus which produces it is due to Kegelaar in 1835. But it was Hering, of Stuttgart, who was the first to make known in a positive manner, in 1845, this form of psora, and who described, dis- tinguished, and exactly figured the Symbiot tliat lives on the Ox.^ This study was undertaken and happily developed by Gerlach in his treatise on scabies. Delafond and Megnin have also, though rarely, met with the Symbiot of the Ox. Symptoms. — This form of scabies has its seat almost exclusively at the base of the tail. The pruritus is moderate. An abundance of scurf covers the affected part ; the hair gradually falls off ; then crusts and cracks form, which are inhabited by numerous acari. It is only when cleanliness of the skin is altogether neglected, that the disease goes beyond the root of the tail, and extends to the back and neck in one direction, and to the perinaBum, mamma?, and inner surface of the thighs in the other direction. In general, it remains localized for years at the base of the tail and in the anal fossa. In some cases observed by Miiller, during the summer the parasite was located along with Psoroptes at the nape of the neck. It is not a serious malady that injures the health of the afi"ected animals to any sensible extent, unless, by neghgence — prolonged for months, or even years — it is allowed to spread to other parts of the body. Then, owing to the general disturbance in the cutaneous func- tions, it may bring on anaemia and the unthriftiness observed among such animals. According to Johne,^ bovine animals often have the Symbiotes on their posterior pasterns without manifesting the shghtest pruritus. Etiology, Contagion. — Symbiotic scabies of the Ox is little con- tagious. Diseased cattle have been known to cohabit with healthy ones for four years without transmitting the disease. It is not con- 1 E. Hering. Wlirtembergische Naturwiss. Jahrcsheftc, I., 1S45, p. S9'; and Reper- torium der Thierheilkunde, VI., 1845, p. 175. - Johne. Bericht uber d. Veteriniirwesen in Sachsen fiir 1877. ACAKIASES. 163 tagious for Man, nor for the other domesticated animals. Deposited on the human skin, the Symbiot of the Ox may produce a few red points and a slight itching, but these phenomena do not persist beyond twelve to sixteen hours. ^ Scurf applied in the pasterns of the Horse causes papules and pruritus that disappear in a few days. Inversely, Delafond and Bourguignon have, on two occasions, deposited a large number of Symbiotes of the Horse — males and females of all ages — on the tail and around the anus of four emaciated and weakly Cows ; the parasites attacked the epidermis, caused scurf, and produced the disease ; but in fifteen days afterwards they had all disappeared, and the scabies was cured spontaneously in twenty days. Dia^osis. — The symbiotic and the psor optic scabies are difficult to distinguish from each other at their commencement. To arrive at a sure diagnosis, prepared by the differential characters of the lesions, it is indispensable to discover the parasite by means of the microscope. A superficial examination might lead to the supposition that sym- biotic scabies was the phthiriasis due to the Trichodectes scalaris, when this has its seat on the posterior parts of the body and root of the tail ; as it is accompanied by a furfuraceous eruption, depilation, and slight pruritus. The distinction between the two diseases is very easy, in- asmuch as the dimensions of the Trichodectus are at least four times greater than those of the Symbiot, and their specific characters are widely different. The tinea tonsurans of the calf can scarcely be mistaken for this scabies, as that dermatomycosis has always a more or less regularly circular form. In the same way, pruri giving two or three minutes' immersion for each. The mixture recommended is Melosson dip, which dissolves rapidly in tepid water, and is non-poisonous, even at five times the necessary strength of 1 to 40. A good dip is the following : Take terebane— cresylic acid, a liquid residue obtainable fi-om carbolic acid — and water, and mix in propor- tion, 1 to 40; add bar soap in proportion of two pounds to each gallon of the terebane, and stir with a wooden rod, warming the mixture in a water-bath until the soap is dissolved, but do not allow it to boil. When the mixture, removed from the fire, ceases to give off vapour, add oil of turpentine one pint to each gallon of terebane, and pour the mixture into casks or carboys ready for use. Add water according to circum- stances. When about to use it for Sheep with chronic scabies, one gallon of the mixture is allowed for forty gallons of water ; for recent cases, one to fifty ; and for lambs — especially for the removal of Lice or Ticks — one to a hundred. The Sheep should be kept in it for at least two minutes, but longer in severe cases ; the dipping should be repeated in eight or ten days.^) Sanitary Police.— The first article of the (French) law on the sani- tary pohce of the domesticated animals of July 21, 1881, enumerates the contagious diseases which demand the apphcation of sanitary measures, and includes 'the scabies of the ovine and caprine species.' Psoroptic scabies is evidently the only serious form that justifies the sohcitude of the authorities ; but, nevertheless, as has been stated (p. 167), the law is also applicable to sarcoptic scabies. With regard to the measures relating to scabies, it is necessary to distinguish them as applying to the interior and to the frontier of a country. 2 ' 1. Internal Sanitary Police. — In the decree of June 22, 1882, concerning the regulation of the public administration of the law on the sanitary police of animals, it is stated : ' Art. 39. — When scabies is discovered among animals of the ovine or caprine species, or in a flock of animals of these species, the Prefet issues an order by which these animals are placed under the observa- tion of the district veterinaiy surgeon. They are not to be allowed to be driven to pasture until curative treatment has been applied, and everything has been done in conformity with the measures prescribed in the order to prevent contact with healthy animals, 0^ J. H. Steel. A Treatise on the Diseaoen of the Sheep, 1890, p. 309.) -' We csinnnt do better than borrow our infonnatioii .m t-his pubject fmrn the excellent Pric'iH (Ic Police Sanit lire Velerinaire of our colleague, PiMf^^ssor Peuch. ACAEIASES. 1S9 'From this it follows that the seabiecT animals ought to be seques- trated until submitted to curative treatment ; so that it is the interest of the owner to apply such treatment as soon as possible, in order to avoid the inconveniences of this sequestration. The treatment of scabies in Sheep and Goats can only be prescribed by a veterinarian, in conformity with Article 12 of the law of July 21, 1881. ' This veterinarian may be either that of the sanitary district or any other, as the cost of treatment is defrayed by the owner of the flock. In any case, the scabied flock remains on the spot, under the surveil- lance of the sanitary veterinarian, who has the right, and whose duty it is to see that the treatment has been applied in a rational and com- plete manner. After this visit he decides whether the animals can be driven to pasture, and if so he recommends the shepherd, and particu- larly the local authority, to be careful that the recently-treated ani- mals do not mix with the healthy animals in their vicinity ; for it may happen that all the parasites are not destroyed, and then the disease will return. It is necessary for the authority to prescribe the roads, lanes, etc., by which the animals are to travel to the pastures. It may also happen that the treatment of the disease will be incomplete and insufificient if the sheepfold be not carefully disinfected. * Disinfection. — Article 19 of the Ministerial order of May 12, 1883, prescribes the procedure of disinfection in the case of Scabies as follows : ' 1. The litter and manure in the sheepfold and the forage left in the racks should be well sprinkled with a disinfecting fluid, then conveyed immediately on to the land. If it cannot be so disposed of, then it must be mixed with the manure in the manure-pit, which should be covered with earth to a depth of four inches. ' 2. The floor, racks, and the walls and woodwork to the height of five feet, are to be washed with water and cleansed, then sprayed with a disinfectant fluid. ' 3. Fumigation is then to be carried out as already prescribed. ^ ' The Sale of Diseased Animals Interdicted. — This interdiction is specified in Article 40 of the Kegulations for Pubhc Administration. ' Art. 40. The disposal of animals affected with scabies is forbidden, no matter what their destination may be. ' This prohibition has a very general bearing ; it applies to animals sold for slaughter, or any other purpose, and its object is deduced from the facility with which the malady is transmitted, its gravity, and the necessity there is for interdicting any movement of the diseased animals before they are cured ; and all the more as the specific treatment for it is simple, cheap, and prompt. Consequently, those who, misunder- standing the prohibition of the administrative authorities, expose for sale or sell these diseased animals, are liable to penalties laid down by 1 This fumigation is made with chlorine or suphurous acid gas. Art. 3. 190 TKEATISE ON PARASITIC DISEASES. the law (Art. 31). Besides, this correctional prosecution does not prevent an action for damages before the proper tribunal, if any injury has been caused by the sale of scabied Sheep. ' Obliyatioii to Disinfect Skins and Wool. — This obligation is set forth in Article 14 of the Public Administration Eegulations. * Art. 41. The skins and wool from animals affected with scabies must not be disposed of until they have been disinfected. This obligation to disinfect is applicable to all the wool from a flock in which scabies has been detected. ' This article is due to the dangers incurred from skins and wool, so far as the contagion of scabies is concerned — at least, to animals of the same species. It should be remarked that the obhgation to disinfect is extended " to all the wool from a flock in which scabies has been found," because these products may shelter the parasites or their ova, and these would spread the disease. In conformity with Article 14 of the Ministerial order of May 12, 1883, disinfection of the skins consists in their immersion in a 2 per cent, solution of sulphate of zinc. With regard to the wool, it should be disinfected by washing in a solution of carbonate of soda, in the proportion of 2 ounces to the quart of water, this wash being afterwards disinfected by the addition of carbolic acid •or sulphate of zinc. ' Bcmoval of the Declaration of Infection. — This is accomphshed by a prefectoral order as soon as the sanitary veterinarian has ascertained that the animals are cured, and the localities have been disinfected (Art. 24, Beg Illations). The owner is therefore most interested in having his flock treated without delay. ' Measures to be adopted when Scabies is discovered in a Fair or Market. — These measures consist in putting the Sheep or Goats in quarantine and immediately treating them. But if the discovery takes place in a town provided with a public slaughter-house, and the owner of the scabied animals is desirous of selling them to the butcher, the district authority will allow him to do so on condition : 1. That removal to the slaughter-house shall take place under the surveillance of a particular person, so as to prevent straggling of the diseased animals ; 2. That the purchasing butcher, or other person who buys them, shall disinfect the skins and wool in the slaughter-house (Arts. 89, 90, Eegu- lations). But it is generally more advantageous for the owner of a scabied flock to treat the animals, than to sell them in bad condition to the butcher. ' The Sheep and Goats which may have been in contact at the fair with the diseased flock, should be notified by telegraph to the authorities -of the place or places to which the animals proceed, by the market authorities, so that on their arrival they may be kept under obser- vation. ACAEIASES. 191 ' 2. Sanitary Police at the Feoxtier. — Paragraph 7 of Article 70 of the Pubhc Administration Eegulations merely states that, in cases of importation of scabied flocks, these shall be sent back. * This measure is relatively easily carried out when the diseased flock arrives at a land frontier ; but when it is a maritime one, it is evident that the animals cannot be re-embarked, nor can they be treated on board ship, supposing the disease has been discovered before they are disembarked. Then they must be isolated on shore, and subjected to treatment as soon as possible ; or if local circumstances will not admit of these measures, the Sheep should be consigned to the slaughter- house or the knackers, according to their condition. In any case, their skins and wool should be treated as above directed. * With regard to those animals which have been in contact with the diseased, but which do not yet show any signs of infection, they must be considered as strongly suspected, and this should be signified by the sanitary inspectors to the authorities of the place to which they are sent, so that they may be watched. It is to be apprehended that, to avoid this surveillance, the senders may make false declarations ; but this may be remedied by preventing their return, and applying to them the penalties awarded under the sanitary law.' 3. Symbiotic Scabies. This form has been observed by Ziirn and by Schleg.^ The Symbiot is similar to that of the Horse, of which it is a variety — Symbiotas communis, var. ovis — though of smaller dimensions than the type. Like the symbiotic scabies of the Horse, this is principally located on the limbs — in the hollow of the pasterns of fine-bred but neglected Sheep, especially the Negretti breed. And like the Horse Symbiotes, those of the Sheep emigrate with difficulty from the region they have invaded, and only slowly ascend towards the upper part of the limbs. The scabies they produce is very slightly contagious, and in a flock there is only a small number of Animals attacked — sometimes no more than one per cent. Ziirn is inclined to ascribe an important share to predisposition and immunity in the etiology of the disease. At its commencement, this scabies is characterized by the redness of the skin and an abundant epidermic desquamation ; later, there appear pale-yellow crusts. The pruritus is somewhat severe — the animals stamping, rubbing and gnawing the affected parts, and so giving rise to an exudation, and the formation of crusts varying in thickness ; while cracks, more or less deep, appear about the pastern. Numerous Symbiotes — among which the males are nearly as abundant as the females— burrow Ibeneath the crusts. The shepherds considered this eruption was due to food too rich in salt, because they observed it when the Sheep were stabled in winter. The hind limbs are first affected, then the fore ones, and the scrotum in the ram, the mammary region in the ewe. The body, neck and head always remain free from it. 1 Zurn. Wochenschrift f. Thierheilkunde u. Viehzucht, XVIII., 1874, p. 121 ; and Die Schmarotzer, I. Theil, p. 18. — Schleg. Siichsen Jahresbericht, 1877, p. 83. 192 TREATISK ON TAKASITIC DISEASES. This form of scabies is not serious, and always disappears with simple cleanliness. In any case, it readily yields to antipsoric treatment. (Goodall, Christchurch, Hants, ^ has quite recently — June, 1891 — dis- covered this Symbiot on the feet of EngHsh Sheep, and he believes it occasions one of the forms of foot-rot, as he has discovered it where that disease was pi-evalent. He has found it in abundance — the males being very few — around the upper part of the claws, in the sebaceous follicles, and more especially on the interdigital skin and in the sinus there. His description of the parasite agrees generally with that given by Neumann. He states that, in his experience, glycerine kills the Symbiotes immediately they come in contact with it. To observe them and watch their movements, he makes a thin circle of Canada balsam on the glass, places the parasites within it, and puts a covering glass over them. They may then be observed ahve for hours, and it will be noticed that the auimalculffi always spread out their legs in good positions as the cover-glass gradually falls on them.) D.— Scabies of the Goat. On the Goat are found Sarcoptes, Psoroptes and Symbiotes. But up to the present time only two forms of scabies have been observed — the sarcoptic and symbiotic. The Psoroptes have only been seen in the pavilion of the ear, producing a benign acariasis, which will be studied when the diseases of the sensory organs are dealt with. The Goat, to judge by the experiments of Delafond, cannot contract psorop- tic scabies ; as he vainly tried to transmit the ordinary scabies of Sheep to that animal, by placing on its skin numerous Psoroptes taken from scabied Sheep. 1. Sarcoptic Scabies.^ Among Thibetan Goats imported into France in 1818, through the instrumentality of Huzard, and in 1819 through the action of Joubert and Ternaux, a large number were affected with scabies, and many of these died. It is difficult to say if the disease was due to the sarcoptic or the symbiotic forms ; but there can be no doubt as to this with regard to the scabies of a Persian Goat, the history of which was published by Henderson, for its disease was communicated to men and horses in the form of sarcoptic mange. And so it was with the epizootic scabies that affected the Goats in the valley of Priittigau, canton of Grisons, Switzerland, in 1851, 1852, 1853. Though Wallraff', who observed it, did find the acarus, the contagiousness of the malady with regard to Man, Horse, and Sheep, and its clinical characters in these, well demonstrated its sarcoptic nature. But it was Franz (1 Goodall. Foot-rot in Shtep ; its Relation to the Presence of the Symliotts spathi- ferus — ovis. The Veterinary Journal, October, 1891.) ^ Comptea Rendus de I'Ecole de Ljon, 1819. — Henderson. The Veterinarian, 1851, p. 252. — Wallraff. Repertoiium der Thierheilkunde, 1854, p. 297. — F. Mtiller. Vierteljahrsscb. f. wiss. Veteriniirkunde, III., 1853, p. 124; XI., 1858, p. 151.— Klingau. Oesterr. landwirthschaftl. Wochenblatt, 1876, No. 38. — Hable. Oesterr. Vierteljahrsschrift, 1877, p. 53. — Koloff. Ueber die Riiude der Ziege. Archiv f. wissensch. u. prakt. Thierheilkunde, 1877, p. 311. ACARIASES. 193 MuUer, of Vienna, who first — in 1853— found Sarcoptes on the dwarf Goats of Africa, and Hebra considered them identical with those of Man. Fiirstenberg studied them, and concluded that they were a distinct species — Sarcoptes vaprm ; and Koloff, who also undertook their study, regarded them as the Sarcoptes squamifcrnsoi Fiirstenberg. Buc it is more just to name the parasite S. scahiei, var. caprce. Symptoms. — From its commencement to its termination, the disease is characterized by great itching. It begins at the head and ears, reaches the trunk and abdomen, the mammae, and finally the limbs — appearing at first in the form of small pimples, from which a viscid fluid exudes, and that soon produces dry, scaly crusts, sometimes furfuraceous, sometimes great thick plates of a shining bluish-gray tint. The hair falls off; the skin becomes thickened, dry, ridged, cracked and adherent ; and the nose and lips are tumefied. Numerous Sarcoptes are found under the crusts. At first limited to a few restricted patches, the malady, if left to itself or insufficiently treated, becomes generalized, and causes rapid emaciation, which may terminate in death. It is capable of assuming an epizootic character. Wallraff remarked that, after the disease had shown itself in some communes of Priittigau during the summer of 1851, it extended in such a manner that in the spring of 1853, in ten communes, containing 2,596 Goats, 1,015 were afi"ected and about 250 had died. When the epizooty had subsided, the total loss amounted to about 500 animals. Klingau reported 100 deaths in a year in one commune. Etiology, Contagion. — The relatively few observations published with regard to sarcoptic scabies of the Goat, show that it attacks, by preference, breeds of Asiatic or African origin. The only exceptions to this are the outbreaks recorded by Wallrail' and Klingau, in which the diseased animals belonged to the local mountain breeds. In the instance recorded in the Compitcs roidiis of the Lyons Veterinary School, they were Thibetan Goats; in that reported by Henderson, it was a Persian Goat ; in that mentioned by Miiller, they were dwarf •Goats from Khartoum, Africa ; and it was in a fat-tailed ram from Africa that Eoloff first saw it. The scabies of that ram was transmitted to a male Goat, which died from it. And it is not impossible that the sarcoptic scabies of the Goat had its origin in the psoric form of noir-musaati. of the Sheep. An experiment made by Eailliet would tend to demonstrate this, as he was able to communicate a generalized and fatal scabies to a Goat by means of the Sheep sarcopt.i Inversely, this scabies of the Goat is transmissible to the Sheep, on which it is localized on the head, as in the natural form of sarcoptic ' Hailliet, quoted by Xocard. Bull, de la Soc. Cent, de Med. V^terinaire, 1890, \x 402. 13 194 TREATISE ON PAKASITIC DISEASES. scabies of that animal. It is only in breeds with dry wool, poor in yolk — Hke the Zackel breed and the Somali Sheep — that it may extend to the other parts of the body, where the wool is scanty and coarse. In Henderson's case, the Goat disease was conveyed to men, who were considered as suffering from itch by the doctors attending upon them. It was the same in the epizooty at Priittigau, where the itch, transferred to the people, assumed a particularly severe character. Horses were also infected in these two instances, and in that alluded to by Wallraff the malady extended also to the Cattle and Pigs. A hei-d guarding the Goats observed by Miiller, was attacked on the hands by an eruption of itch, which was cured by sulphur ointment. Eoloif has also collected a number of instances of pure itch occurring iti people who had been in contact with his scabied Goats. On the other hand, in his experiments he could not succeed in implanting this Goat mange on other animals except short-woolled Sheep — Somalis — or Sheep with scanty wool — fat-tailed Sheep. With Merino Sheep, the Pig, Dog, Ass and Rabbit, he only obtained a very ephe- meral scabies, or absolutely negative results. Treatment. — In cases in which flocks of Goats are affected, the treatment by antipsoric baths — as in the psora of the Sheep — is applic- able ; but it is attended by greater difficulties, owing to the greater vivacity of the Caprine species. Wallrafi' was completely successful with Walz's bath, which was followed by an ointment having sulphur and soft soap for its base. But some of the Goats plunged their head in the liquid, swallowed some of it, and died from poisoning. For isolated cases, after clipping off the hair, recourse may be had to one of the antipsoric applications already mentioned for the sarcop- tic scabies of the Horse. Sanitary Police.— What has been stated with regard to the psorop- tic scabies of the Sheep, is appUcable — according to the law— to the sarcoptic scabies of the Goat. 2. Symbiotic Scabies. This scabies has been studied by Delafond in the Jardin des Plautes, Paris, on Angora Goats in 1H54. He recognised the parasite as belonging to the genus he named Sarco-dcrmatodcctc — the Symbiot. Eailliet observed — even on Delafond's preparations — that the male of this variety had many of the foliaceous bristles indicated by Mcf^nin as characteristic of the Symhiolcs coiinimnis. Mollereau has recently witnessed an altogether pecuhar instance of this psora. ^ The symbiotic scabies studied by Delafond began on the sides of the neck, behind the ears, on the withers, the back and loins, and some- times at the root of the tail — ^more rarely on the sides of the chest and at the flanks. It produces more or less extensive, though at first incomplete, depilations, in consequence of shedding of the wool and 1 Mollereau. Gale Symhiotique, dc la Cliivre. V>\\\\. de la Sue. Cent, de M^d. Veterinaire, 1889, p. 156. ACARIASES. 195 persistence of the hair. Yellow, hard, thick and coarse crusts form, which are very adherent ; and beneath them the skin is hypertrophied, dry, wrinkled, cracked and adherent. ' Arrived at this stage, the scabies might be mistaken for an ichtyosis,' without the presence of the parasites. Softened with tepid water, tlie crust rapidly becomes a whitish pulp, which, under the microscope, is seen to be composed of granules, distorted pus cells, and almost exclusively of epidermic cells. The Symbiotes are always beneath the crusts, and especially those of recent formation. The lesions of the skin induce tumefaction of the neighbouring lymphatic glands. The wool of the Angora Goats becomes matted and falls off in locks, the hairs of which are dirty at the roots, and have lost their elasticity, softness and lustre ; so that combing it out is difficult, and there is much waste. At those points where the disease is very old, the fibres of the wool are short, thin, and atrophied, very fine at the end, and much intermixed with the hairs proper. This scabies has a slow course, and may remain for two or three months confined to the sacro-lumbar region ; it is only after that period that it has descended to the chest and flanks, and on the limbs to the knees and hocks. It does not affect the face, ears, testicles, mamma\ tail, or lower part of the legs. It is easy to mistake it for sarcoptic scabies ; but they may be dis- tinguished from each other by their seat — at least, by their extreme generahzation — by the appearance of the crusts, and more particularly, though not exclusively, by the characters of their special parasites. In the instance recorded by Mollereau, the scabies was localized on a hind-pastern, and was manifested by a hard ring which had com- pressed the neighbouring parts, producing an oedematous swelling, and even commencing mortification of the skin ; consequently, there was intense lameness. This thick crust was formed by shreds of straw agglutinated by serosity ; its inner surface covered a multitude of the Si/m h iotes communis. The treatment followed by Delafond consisted in clipping off the wool, then employing alkaline baths — about 7 to 11 pounds of carbonate of potass or soda to 22 gallons of water. The concentration of the fluid is subordinate to the thickness of the crusts, and the immersion is for a quarter of an hour, being accompanied by vigorous rubbing. ' Two or three baths, and four or five rough rubbings, at four or five days' interval, are sufficient to effect a cure.' Delafond advises, in addition, local applications of Helmerich's pomade, oil of turpentine, tar, etc.; but every kind of convenient antipsoric treatment, judiciously applied, will yield good results. E.— Scabies of the Pig. The Pig has only one kind of scabies — the sarcoptic form — due to the Sarcoptes scabiei, var. suis; the S. squamifenis Fiirstenberg.^ It was a long time ago described by Viborg, but search for the acarus ' We cannot admit that there are two kinds of sarcoptic .scabies, due to two different varieties of Sarcoptes scabiei. This distinction has been made by Megwin after an incomplete examination of Delafond's description, and of too brief notes supplied by (iuzzoni. One of these forms was scabies of the trunk, the other that of the ears, and the sarcoptes which caused them differed in size ; the one must have been the S. sc. •>■«(•<, and the other was mistaken for the S. sc. homiiUH. Our notice of Pig .scabies will show our leasons — until better informed — for rejecting this distinction. 13—2 196 TREATISE ON PAKASITIC DISEASES. producing it was unsuccessful. In 1847, Gurlt and Spinola had cer- tainly found a Sarcopt in the scabies of a wild Boar, and some years afterwards the same experience occurred to Ilertwig and Gerlach ; but all failed to find the parasite on the domestic Pig. It was Delafond who, in 1857, discovered it at Alfort on two young Pigs of the Anglo- French breed, and intended for surgical operations. Subsequently, Miiller, of Vienna, in 1864, and Kocourek, in 1865, found this Sarcopt on Chinese Pigs.^ We have also seen this scabies at Toulouse, affect- ing a Yorkshire sow and her progeny. Symptoms. — This scabies begins with a violent pruritus. It appears to be at first localized on the head — chiefly on the ears and around the eyes, then at the withers, croup, and inner surface of the thighs ; later it invades the entire surface of the body. In recent cases, no galleries are observed, but only some red, closely-set papules. The morbid secretions and the abundance of epidermic cells cause the formation of dry, whitish-gray, lustrous crusts, which are adherent while yet thin, but easily detached when not so, and sometimes attaining a thick- ness of 5 mm. to 10 mm. The skin is wrinkled, and the bristles are either shed oj- pushed from their follicles : they lie on the surface of the integument, agglutinated into small tufts, to fall off afterwards. The crusts are more or less extensive, according to the age of the disease. Frequently the whole head is invaded, and even the greater part of the trunk, when the animals look as if powdered with dry guano, accord- ing to the remark of Miiller. Beneath the crusts the skin is excoriated and cracked, especially at the bottom of the wrinkles ; and on the chest and abdomen it may become 3 cm. or 4 cm. thick. In the other regions — and particularly at the base of the ears — the hypertrophied papillae form tubercles from the size of a pea to that of a bean, and which may be compared, for shape and dimensions, to the papilljB on the Ox's tongue, or the warts on a Cow's teats or lips of the Dog. These hypertrophied cutaneous papilkc are embedded in the crusts, beneath which the Sarcoptes are found. In order to discover the parasites, it is sometimes necessary to scrape the skin to the quick, and even then the search will often be without result ; this explains the non-success of the earlier investi- gations. The size of the parasites renders them perceptible to the naked eye, and especially if a pocket lens is used. They are the largest variety of the Sarcoptes scahlci, the ovigerous female measuring from •40 mm. to -50 mm. long, and -32 mm. to -39 mm. broad ; while the male is -25 mm. to -35 mm. long, and -19 mm. to -30 mm. broad. Guzzoni found some, in scabies of the ears, the dimensions of which were about those of S. scabiei, var. hominis, the ovigerous female being * Viborg. Tralle stir les Maladies du Pore. Soc. Cent. d'Agric. de la Seine, ] 805. Published' in 1823. —Delafond. Recueil de M^decine V^terinaire, 1857, p. 459.— Midler. Oesterr. Vierteljahres.scli. f. wissenscb. Thierheilkunde, 1864. — Kocourek. Ibid., 1865. ACAKIASES. 197 •30 mm. long, and -26 mm. broad ; and the male -20 mm. long, and •16 mm. broad. Swine scabies progresses slowly. When it has invaded a large sur- face of the body, it hindei's fattening and gradually causes marasmus. Etiolog'y, Contagion. — This scabies appears to be rare, although it is stated to be relatively frequent in Holland, and more prevalent in the centre and west of France than in the other parts of the country. It is possible that, as Viborg asserts, excessive misery and uncleanli- ness are the predisposing causes. Contagion is evidently the only efificient cause, though it does not appear to be alike for all animals ; for it has been already shown that the disease has been more particularly studied on Pigs of improved breeds ; and it has been observed that young Pigs of common breed have been in daily contact with those of English breed — and which contracted the disease from their parent — without becoming infested. There is nothing in the accounts of this scabies which allows of the disease being traced to its source. ' It is not rare,' says Viborg, ' for Pigs to take the mange from burrowing in the manure of mangy Sheep, Cattle and Horses.' This is a bold assertion which experiments do not justify, as Gerlach has inoculated Pigs with Sarcoptes from the Horse and Cat, with a negative result ; and according to Spinola, the Sarcopt of the wild Boar only will, when transferred to the domestic Pig, cause mange. The scabies of the Pig is contagious for Man, as the cHnical observa- tions of Bateman,! von Gemmern, Bontekoe, and Heckmeyer — quoted by Delafond and Bourguignou — prove ; but the eruption disappears spontaneously in about five days. Depositing the Sarcoptes of the wild Boar on the arm of Man induces an exanthem which disappears in eight to ten days (Gerlach). Delafond contracted the disease in studying and dissecting the skin of an affected Pig ; the malady pro- gressed slowly, and it was only towards the thirtieth day that it threatened to become generalized, when Delafond cured himself with Helmerich's pomade. At the Dresden Veterinary School,- two students, by means of a bandage, fastened on their arm a piece of diseased skin from a mangy Sow, and there resulted a very pruriginous itch that, in one of them, subsided of itself in about forty-eight hours, but in the other had to be treated by creosote ointment. Scabies of the Pig is transmissible, according to Viborg, to all the domesticated animals ; but Am-Pach— quoted by Gerlach— states that it is only communicated to the Dog. At Dresden, a fragment of the skin of a mangy Pig was fixed on the neck of a dog ; this gave rise to a violent pruritus that reached its maximum in about forty-eight hours; then it gradually subsided, and on the eighth day had disappeared. ^ T. Bateman. Delineations of the Cutaneous Diseases, London, 1817. - Bericht ti' er clas Veteriniirwesen im K. Sachsen flir 1877, p. 60. 198 TKEATISE ON PARASITIC DISEASES. The same experiment made on the back of a Sheep was absolutely negative; but the proof would have been more convincing if the attempt had been made on the face of the Sheep, which is the seat of the sarcoptic scabies special to the ovine species. Treatment. — The disinfection of the pigsties is a necessary prophy- lactic measure. Treatment consists at first of alkaline baths, accom- panied by vigorous friction, so as to remove as many of the crusts as possible. As an antipsoric remedy, Viborg has recommended a decoc- tion of an ounce of tobacco in half a gallon of water, to be reduced to a quart. In the case of chronic and extensive disease, Delafond counsels several hard lubbings with Helmerich's pomade, or with a mixture of oil of turpentine 8 parts and flowers of sulphur 1 pax't. The use of Helmerich's pomade has given us an easy and complete success in the case of a Sow and her litter. F.— Sarcoptic Scabies of the Rabbit. We have already seen that, in the fur of the Ealjbit, we may find three kinds of microscopical Acarina not belonging to the psoric Sarcoptidae, and rarely causing cutaneous lesions. These are the pteroptoid Gamasus (p. 105), the parasitivorous Cheyletus (p. 109), and the Listrophorus gibbus (p. 111). Independently of these Acarina, a Sarcopt and a Psoropt live on the head of the Rabbit and produce two diseases — a sarcoptic scabies, and a psoroptic acariasis having its seat in the ear. The latter will be studied hereafter, when the parasitic maladies of the sensory organs are considered. ^ Gohier asserted that he had seen this scabies on the domestic Rabbit, and discovered the parasite. Huzard has given a description of the affection- ; and Gerlach also describes it, and gives a figure of the parasite, which he names the SarcojHes cuniculi. We have already said that it belongs to the Sarcoptes minor, var. cuniculi — -it being so placed by Fiirstenberg. Railliet has had occasion to study this scabies. Symptoms. — Sarcoptic scabies at first affects the nose, then the lips and the forehead. Gerlach has never seen it extend beyond this ; but in a Rabbit which died from it, Railliet noted that, after the malady had attained the margin of the eyes, the face, forehead, and lips, it reached the lower jaw to the root of the neck, the lower half of the outer surface of the auricular concha, the fore-legs as far as the elbows, and the hind ones to the hocks. It produces an acute pruritus, which compels the rabbits to rub against anything near them, and to scratch ' We believe we ought — at least provisionally — to make an exception in the case of a symbiotic acariasis, the existence of whicii has beer} indicated by Zurn in the Augsburg W'ochennchi-ift for 1874, and which appears to have been due to a Si/mhiotCH cuiticuli. The disease was located in the extevn(), p. .585. — A. J. Haslam. A Page of CameHw Pntholony. The Veterinary Journal, XXII., 1886, p. 16. — Marcone. Bofjna t>arcoj>tica net JJromedario. Giorn. di Vtter. Militaire, 1888, p. 152. — J. H. Steel. Cameihie Pat/tolo(/v. The (Quarterly Journal of Veterinary Science in India, VII., 1889, p. 27. A"Maimal of the JJiseaxe.s of the Camel, 1890. —(Fleming. Veterinary Sanitary Science and Police, II., p. 4G1.) ACAEIASES. 201 ness no doubt play an important part. Youug and old animals are more often mangy than adults ; and it is in the springtime that the malady prevails among Dromedaries, and invades the greater part of the cutaneous surface. But it is clear that contagion is the efficient cause, favoured by the promiscuousness in which the Camels and Dromedaries employed in caravans live — carrying baggage, food and munitions of armies. Vallon states that when a mangy animal is introduced into a healthy troop, fifteen or twenty days afterwards cases of the disease appear among the latter, and soon all arc infested. The scabies of the Camel and Dromedary is transmissible to Man. Louis Franck, Straus-Durckheim, and Hamon have given instances.^ The best-known case is that which Biett has reported. Six Dromedaries sent from Egypt to the Museum of Natural History (Paris), in 1827, were attacked by scabies, which was communicated to the men who cleaned them. ' Ten of these men,' says Biett, ' were admitted to the Saint-Louis Hospital. The eruption was so intense on several of them, that there supervened symptoms of gastro-intestinal inflammation, and in two of them — vigorously-constituted men — there was general infil- tration.' According to Palgrave, the itch that frequently affects mankind in Arabia appears to be derived from the Camel, on which it is very common. Berenger-Feraud has observed a psoric disease in Senegal, named larhiach by the Oulofs and Toucolors, and which is characterized by the presence, on the fingers and other parts of the body, of furrows like those of scabies. The parasite has not yet been seen, but Carpot thinks that it is the Sarcopt of mange of the Dromedary (R. Blanchard). Treatment. — The development of scabies in the Dromedary, as well as its transmission, can be prevented by keeping the skin always clean, in properly sheltering the animals, in sparing them from long fatigue and privations, and more especially in preventing them from coming in contact with mangy animals. During treatment, they should have alible nourishment, with exercise every day, and their hygiene should be ameliorated in every way possible. The treatment is begun by general chpping, if the malady has not yet caused vast depilation. On the shores of the Red Sea, the mangy Camels are often treated by simply bathing them in the sea for half an hour every day, and when they come out of the water an experienced native rubs the skin with a pohshed stone, while another throws water over the parts that are rubbed — the operation being terminated by thorough washing. The rubbing with the stone has to be carefully ^ Franck. Collection d'Opuscules de Med. Pratique, etc., Pari.s, 1819, p. f).— Straus- Durckheim, quoted by Herinir. — HanHni. L' Eiiypte soun Mchemet-Ali, I., pp. 514, 584. 202 TREATISE ON PARASITIC DISEASES. carried out, so as not to produce new excoriations or cause the old ones to bleed. Lotions of sulphurated potash completely failed at Alfort in 1827. In Africa, from time immemorial, tar has been considered a panacea against scabies. The Prophet said : ' For mange of the Camel, tar is the remedy ' (Vallon). And when the Dromedary is two years old, the Arabs are in the habit of rubbing it with tar three times a year after clipping, in oi'der to protect it from mange and the attacks of flies. This tar is obtained from the wood of the Junipenis ^;//c«/»'cea and Thuya articulata. They make a mixture of two parts of tar to one of water, rubbing it on the skin moderately warm, when it appears homo- geneous. This tarring requires particular care ; for when the mixture is too strong, the animals succumb to a kind of cutaneous asphyxia — instances of which occur every year. Such accidents are averted by employing a mixture of tar and soft soap, applied rather wax-m. The Arabs in Egypt dilute the tar with fish-oil.^ H.— Sarcoptic Scabies of the Dog. Independently of the demodecic scabies, the Dog may have an ordinary scabies — the sarcoptic — due to the Sarcoptca scabiei ; an auricular acariasis — symbiotic — caused by the Sijmbiotes auricidancm of Lucas and Nicolet, the Chorwptes ecaudatus of Megnin. The latter will be noticed in the chapter on parasitic affections of the ear. In practice, the sai'coptic scabies of the Dog is considered a common disease ; but many of those who have assiduously sought for the Sarcopt regard it as rare. Fiirstenberg and Delafond, in their numerous investigations, have met with it — the first in one instance, the second in two ; and Megnin has only found it in two or three cases among the hundreds of Dogs he examined, and which were considered mangy. Our own researches remained fruitless until we began to employ the solution of potass (see p. 132) ; since then the parasite has not been rare. Observers — such as Bosc, Gohier, Bonnes, Hertwig and Hering- — have for a long time noticed the occurrence of psoric SarcoptidoG on the Dog ; but the descriptions they give are too brief or too incomplete, and it is not at all certain that they had to do with the Sarcoptes. (^ 'The itch, and its best remedy, sulphur, abound from one end of Arabia to the other ; but the unskilfulness of the Arabs themselves in the application of the mineral often thwarts its effect, or leaves it only partial. This unseemly affection is cummon among Camels, and from them is frequently communicated to men.' Palgrave. Eastern and Central Arabia, II., p. :54. In the Soudan expeditions in 188.') and 1887, the Camels supplied to the English troops suffered very much from mange, and the losses were, consequently, very heavy.) - Bosc, Hertwig, quoted Ijy Hering. Nova Acta Phvsico-Medica Academiae Naturae Cnriosoruni, XVIIl. (pars posterior) 18:J8, p. ^>7'i. — Gohier. M^m. siir la Med. et la Chirurfi. Veterinaire, I., 1813, p. 10; II., 1816, pp. 52, 223. — Bonnes. Comptes Rendus de I'Acad. des Sciences, IS'.iS, 1 Sem., p. 613. ACARIASES. 203 Gerlach has described the Sarcoptes of the Dog and the scabies it determines ; but his description of the Sarcopt is, unfortunately, incomplete and inexact in many points. Gurlt and Fiirstenberg found on a mangy Dog a variety of Sarcopt of large dimensions, which might be the same kind met with by RailHet and Cadiot on a Dog affected with crusted mange ; the same was also observed by Megnin on Wolves in a menagerie, which also had this crusted form of scabies — this was the S. scabici, var. lupi ; and it was also the same as that found by Fiirstenberg in the scabies of Man known as Norwegian itch — so named from the country in which it is most frequently seen — a variety of the parasite that he designated S. scabici critstosce} The Sarcopt of ordinary sarcoptic mange of the Dog — which was certainly seen first by Delafond, then by Megnin, Railliet and Cadiot, etc. — is a little larger than that of Man ; it is the S. scabici, var. canis. Symptoms. — Sarcoptic scabies may appear on any part of the body, but it usually begins on the head, muzzle, around the eyes, and on the ears. It then reaches the belly, the under surface of the chest, the sides, root of the tail, legs, etc., and this so rapidly, that at the end of a month the invasion is general. It first manifests itself by red punctiform spots, resembling Flea-bites, and which can only be seen where the skin is thin and not pigmented — as on the abdomen, in the arm-pits and flanks — though rubbing often lenders them diffuse. On these surfaces the early red points are soon converted into papules from the size of a lentil to that of a pea, the summit of which becomes vesiculous, ruptures, and allows much serosity to escape. This effect is most frequently due to the repeated scratchings under the influence of the pruritus, which lead to the pro- duction of more or less extensive moist patches. There may also be seen — and particularly on the fine skin of the belly and flanks — vesicles which are being transformed into pustules — a dark point in their centre communicating with the gallery of the Sarcopt. Some- times the mange remains dry, and is marked by an abundant formation of scurf and by depilations. As a rule, the surfaces first invaded become dry, and are covered by grayish-yellow crusts, which gradually scale off. The depilated and thickened skin becomes ridged, wrinkled, and excoriated ; and in cases of generalized scabies the Dog exhales an offensive odour, and presents a repulsive appearance. The pruritus is always intense, particularly if the patient is kept in a warm place, and after running. The disease induces a grave state of cachexia and marasmus by the insomnia, continual agitation, depriva- ' According to the celebiattd dermatologist, Hcbra, the Norwegian itch i.s not due to a particular kind oi iSaicopt, as was at tir>t believtd, but to the »S'. scahiei, var. hominis, of ordinary fcabies, frotn which it only differs in the greater number of the Sarcoptes and the accumulation of their debri.-. 204 TIJRATISE ON PAKASITIC DISEASES. tion of rest, and suspension of the cutaneous functions ; and death ensues in two or three months if treatment is not adopted. Diagnosis. — Follicular or demodecic scabies is often mistaken for sarcoptic scabies, and this confusion entails an erroneous prognosis ; for while the first is very difficult to cure, the latter is comparatively easy to get rid of. Follicular scabies commences like sarcoptic scabies, but the surface it affects is dry ; in the latter form it is covered with small yellov^'^ crusts^ and the papules rarely become pustules — while the acne pimples are, on the contrary, an almost constant sign of follicular scabies, which is also less prurigiilous and slower In its^course. But discovery of the parasite confirms the diagnosis. Sarcoptic scabies anay also be confounded with what has been termed red mange {rouge or rougct) — a frequent, but non-parasitic, skin affection of young Dogs, which commences beneath the chest and abdomen and inner surface of the limbs, and is characterized by the red colour of the skin, the almost total absence of humidity, and much itching. Another skin disease \sth.eroux-vicux, dartre seche, rogue (dry mange), which is frequent on old or fat Dogs, and is located on the back, more especially on the loins, where it is recognised by the erect hairs — which are reddish at their base — and by the induration of the skin, which is thickened, wrinkled and cracked, brownish-red, slightly pruriginous, and from its cracks there may exude a sero-sanguineous fluid that, on drying, becomes brown irregular crusts. These different signs, as well as the absence of the parasite, lead to a diagnosis. The liuniid )iu(uge or tetter (dartre humide or dartre vice) has a varied seat, and consists in more or less depilated, irregular patches, showing numerous small vesicles, the contents of which escape and keep the diseased surface always moist. There is no parasite, and the malady extends slowly. The dri/ or scaly eczema {dartre sbche, dartre far incuse), ov pitijriasis, is very tenacious in old Dogs, and is situated on the head, neck, and back, causing moderate pruritus, and having little tendency to spread ; it is also recognised by the abundance of epidermic pellicles that cover the diseased surface. Lastly, troiiihidiau. acariasis, due to the larval hexapod of the Trom- bidiuvi liolosericeuui (see p. lOG), has its principal seat around the eyes, and on the paws and belly. A careful examination will discover the parasite, and thus eliminate scabies from the diagnosis. Etiology, Contagion. — Youth, debility, or a sickly condition may be considered as predisposing, but not necessary causes ; for the Sar- coptes will live on animals of all ages and in all conditions. The existence of follicular scabies also predisposes to the invasion of sarcop- tic scabies ; but it is evident that contagion is the essential cause. The admitted rarity of this malady has led to the supposition that Dogs suffering from it have been in contact with itchy people, or have con- ACARIASES. 205 tracted it while hunting game (Wolf, Wild Boar) affected with j)sora. But it has been seen in an epizootic form ; for in Germany, in 1890, it attacked 10 per cent, of the Dogs, especially in such cities as Berlin, Munich, Stuttgart, and Cologne.^ ' During the year 1886-87, of 8,399 animals attending the canine clinic of the Berlin school, 639 were affected wath sarcoptic mange. The asylums for Dogs contributed largely to its dissemination ' (Friedberger and Frohner). Facts of contagion from Dog to Dog — to-day a matter of current observation— have been published by Eayer, Littre, Leblanc, Sabatier,- and have been well established by Delafond, who also observed that the sarcoptic scabies of the Cat may be transmitted to the Dog, although due to the Sarcoptes minor, and not to the Sarcoptcs scabiei. He deposited on the skin of a bitch in perfect health, 125 Sarcoptes taken from a mangy Cat ; and in about a month she was covered with a generalized scabies. In another experiment, four mangy kittens were put to a bitch, which suckled them along with three puppies that she was already nursing. She became mangy, as well as her own progeny, which died of the disease in about two months. Delafond did not succeed in developing mange of the Dog by Sar- coptes taken from psoric people. On the contrary, however, numerous examples show that Dog scabies can be transmitted to Man.'^ Chabert says that Dog mange is communicated to Man in a very obstinate form. Grognier has seen a student whose hands were covered with itch after having rubbed a mangy Dog. Viborg gives an instance of a Man and Woman who became psoric from a Dog they possessed. Mouronval furnishes a similar instance. Cbavassieu d'Audebert assures us that the Dog and Cat may transmit a very troublesome itch to Man. Biett has seen a child which became infected through caressing a mangy Dog. Hertwig, Heckmeyer, Stiitz, and Marrel have published observations of the same kind. Delafond saw a student contract the itch on attending a diseased Dog ; and he himself became infected by depositing the Sarcoptes of the Dog on his skin, the itch resulting continuing for about forty-five days, and only ceasing on the adoption of antipsoric treatment. The same experi- mental result was produced on a student ; on two others there was only a fugaceous eruption. Lastly, Gerlach was likewise able to transmit the mange of the Dog to Man, and states that he on two occasions witnessed spontaneous trai:ismission. More recently, Friedberger has seen such transmission from Dogs to women and children ; in the latter there was a very pruriginous eruption between the fingers, and 1 L'Elereur, 1S91, p. 13. ^ Thesis of Got, 1844, 3 Chabert. Traite aur la Gale et les Dartres, 1802, p. 22. — Grognier. Compte rendu de I'Ecole de Lyou, 1817. — Viborg, Mouronval, Chavassieu d'Audebert, quoted by Delafond and Bourguignon. — Biett. Dictionn. de Medecine, 2nd edition, XIII., Pat is, 1836, p. 544. — Hertwig, Heckmeyer, Stuetz, quoted by S. V. H. Trans- misiiton de tjuelijues Maladies de-s Ani7nanx a rHomme, Journal Vet. et Agric. de Belgique, 1842, pp. 331, 335. — Marrel. Recueil de Med. Veterinaire, 1847, p. 1001. — Fenger. Tidsskrift for Veterinairer, 1865, in Repertorium der Thierheilkunde, 1866, p. 277. — Friedlicrger. Jahresbericht der Thierarzneischule in Miinchen, 1873, p. 43. — Leonhard. Archiv f. wissensch. u. prakt. Thierheilkunde, 1886, p. 2P2. 206 TREATISK OX PAKASITIC DISEASES. on the arms and abclonien. Leonhard reports an analogous case. We have also known of another ; and in the epizooty that occurred in Ger- many in 1890, hundreds of people who had been in contact with mangy dogs in Berlin were contaminated. Frohner in one month reported twenty-one cases of this contagion. According to Ziirn, the Sarcopt of the Dog can be conveyed to the Pig and Horse. Treatment. — Contagion must be prevented by isolating diseased from healthy Dogs, burning litter, washing kennels — the wooden portions with boiling water kept so in the place to be cleansed, or with creolinated water, 5 to 100 — the parts in masonry being lime-washed ; in a word, carrying out the various measures already repeatedly indicated. To combat the debilitating effects of the mange, an abundance of animal and vegetable food — varied and substantial — should be given, combined with tonics. Exercise, and living in the open air as much as possible, should also be allowed. With regard to medical treatment, the first operation to be carried out is general clipping for long-haired Dogs, no matter how limited the diseased parts may appear. Cleanliness is indispensable. The litter must be frequently renewed, and the patient must be well washed with soft soap and water ; a vigorous brushing in the bath at the same time will remove the crusts and diminish the number of parasites. Care must be taken that the animal does not lick off the remedy — especially if it is toxic — by employing a muzzle or a leather covering. The antipsoric remedies that may be employed are numerous. Friedberger and Frohner much recommend creolin^ in the form of a liniment composed of creolin and soft soap, 1 part of each, alcohol h to 10 parts, according to the extent and degree of the malady. In generalized scabies, one-third of the body is dressed each day, and a cure is effected in from eight to twenty days. Alcoholized creolin may be employed, 1 to 10, or 1 to 20, or creolin soap. This agent is very efficacious, and absolutely without danger. At the Toulouse Veterinary School, covadille-oil is usually employed (see p. 148), sometimes cade oil, or a mixture of equal parts of oil of petroleum and linseed oil. Gerlach approved of Peruvian balsam dissolved in alcohol, 1 to 30 ; its vanilla-like odour renders it suitable for house Dogs. Styrax may be used in the same way. These medicaments give excellent results. Many practitioners employ simple carbolized soap — that is, carbolic acid incorporated with soap in the proportion of 1 to 20 ; the animal is smeared over with it before it is washed off. The pomade of Helmerich — about 100 grammes for a medium-sized Dog — is a simple send, frequently-employed remedy. When the Dog (* Creolin is better known in England as a refined preparation of Jeyes' Flnid.) ACARIASES. 207 has been well dried after its soap bath, it receives a first dressino', which is left on for twenty-four hours. Next day this is washed off with soap and water, and a second dressing is applied. If it has acted well, there is rarely any necessity for applying a third dressing. Tar cannot be recommended, as it is dangerous to cover all the surface of the skin with it. Ellenberger and Hofmeisteri have reported a case of fatal poisoning of a Dog which was affected with mange, and had the whole body covered with tar. If this substance is employed, it should be mixed with an equal quantity of soft soap, and alcohol added to give the mixture the consistence of a liniment. The dressing should be extended over three days, only one-third of the body being dressed each day, and a bath given on the fourth day. This series of operations ought to be repeated three or four times. The oil of lavender and oil of turpentine have often been used for mange of the Dog ; but the first is uncertain in its effects, and the second is too irritating, although it forms the most active ingredient in the following application, which is much appreciated by sportsmen and veterinary surgeons : Sea salt - - - . . . - 150 grammes. Gunpowder - - - - - - - 10 „ Flowers of sulphur ---.-. 140 ]\ Vinegar ----... 1 litre. The mixture is made at a boiling temperature, and continually stirred. When it is homogeneous, it is allowed to cool until tepid, and then there is carefully mixed with it : Oil of turpentine - - - - - - 90 grammes. This remedy is employed tepid. It causes an irritation of the skin that does not disappear for some days, and it is therefore not to be recommended. Another remedy generally employed also by sportsmen and dog- keepers, and which was indicated in 1740 by Gaflet de la Brifardiere, and recommended by Prange under the name of oleo-sidplmret of tannin,- comprises : Xut oil ------ - 1500 grammes. Powdered nut-galls - - - - - - 30 „ Sublimed sulphur - - - - - - SO „ Heat the oil until the finger cannot be held in it, then gradually add the sulphur, and constantly stir with a wooden spatula, adding in the same way the nut-galls ; after- wards heat the whole for half an hour. This remedy is efficacious, but it possesses no real superiority, and has the disadvantage of irritating the skin. Benzine and creosote are recommended by Gerlach and Ziirn, when mixed with oil or alcohol — 1 to 30 to 60 ; but it has been reported that they are too irritating, and even toxic. ' Ellenberger and Hofmeister. Jahresbericht iiber d. Leistungen auf d. Gebiete der Vet.-Medicin, lb82. - Gaffet de la Brifardiere. Xouveou Traits de Venerie, 1740. — Prange. Rec. de Med. Vet. Pratique, 1848, p. 269 ; 1850, p. 656. 208 TREATISE ON PARASITIC DISEASES. Naphthalin, lauded by Fiirbringer, Fischer, etc., has been successfully employed by Siedanigrotzky,' in the following form : Naphthalin ------ 11 :"> grammes. Vaseline ------ Tfi ,, Oil of thyme - - - - - I ■- s rirmi* Oil of lavender ^ aa ^ drop.. The cure is complete in twelve to fourteen days. This is a cheap remedy and soothing to the skin ; it answers when the disease is com- mencing, and for house Dogs. I.— Sarcoptic Scabies of the Cat. The Cat may be affected with a sarcoptic scabies, due to the SarcojJtea minor, var. cati (see p. 124), and a symbiotic acariasis due — like that of the Dog — to the Symbiotcs auric ularuvi. (See Parasitic Diseases of the Ear.) The earliest mention of Scabies of the Cat is due to Wedelius. In 1672, he described an epizooty which, in two years, and for an extent of some miles, prevailed in Westphalia with such violence that nearly all the Cats perished. Notwithstanding the manifest ex- aggeration in his account — and particularly with regard to the changes occurring in the eyes — it seems very probable that it was scabies he saw. Girtanner has alao published some positive documents on this affection. Rigot, in 1811, remarked on an outbreak of scabies among Cats in the neighbourhood of Chateau-Gontier, Mayenne, and which prevailed for nearly four years ; and, in 1827, Sajous, a veterinary surgeon at Tarbes, presented a memoir to the Central Society of Agriculture, on an epizo(')ty of scabies which had existed for some years, and had killed all the Cats in entire villages. Analogous observations, of which mention will be made hereafter, have also been published ; aud altogether they prove that the malady has been known for a long time. If Gohier was the first writer who speaks of having seen the Sarcopt of the Cat in 1813, Hering has given the first description of it ; but he only saw the male, and is inexact in several details. The Sarcopt is now well known, owing to the works of Rayer, Gerlach, Fiirstenberg, and Delafond and Bourguignon. The latter considered it to be a distinct species, and named it the " Sarcopte iiotot'dre," a designation given because of the dorsal position of the ;inus. Fiirstenberg named it the Sarcoptcs minor, and in this species It forms the variety cati.- Symptoms. — Scabies of the Cat usually commences on the neck, reaches the ears and forehead, then all the head, and rarely goes beyond ^ Siedamgrotzky. Bericht ii. d. Veteriniirwespn im K. Sachsen f. 1882, p. 22. '^ Wedelius. Collect. Acad., III., p. 1.56 (quoted by Sauvajjes), and ^phemerides des Curieux de la Nature, 1672, p. 259 ((quoted by Delafond and Bonrt^uiffnon). — (iirtanner. Bibliotheijue Medicale de Blumenbach, III., and Instructions Veterinaires, V., p. 350, 2nd edit., An XII. — Rigot. Correspondence V^terinaire, published by Fromage de Feut;re, III., 1811, p. 188. — Gohier. Mtm. xiir la Med. et la Chir. Vettrinnire, I., 1813, p. 10. — Hering. Nova Acta Physico-Medica Acad. Naturae Curiosorum, XVIII. . ; while the width at the thorax varies f/;n between 40 ji and 5-5 /x. h-\ The Demodex are oviparous. The eggs are l'^ 60 /x to 90 /x long, and 20 /x to 50 /x broad, and are \m cordiform or fusiform in shape. From the egg issues |h a larval hexapod, the legs of which are only repre- ^ sented by three pairs of tubercles, while the buccal Fig. 85.— Evolution organs are yet in a rudimentary condition. After tn&L-i?n?Tt\Z ^: "lou^ti^g' tl^e larva becomes an octopod, the "Do-t ; magnified one fourth pair of legs being still tubercles, like the hundred diameters. Other three pairs. A second moulting transforms — Railliet. this larval octopod into anympha, which possesses 1, ovum ; 2, larval ^^6 legs and buccal organs of the perfect state, hexapod ; 3, larval from which it only differs in the absence of sexual octopod. organs in the male, the acquisition of these being the result of a last transformation. The Demodex have been found on Man, and the Dog, Cat, Goat, Pig, Sheep, Ox, Horse, Aristotlean Deer (Prietsch), Fox (Gros) ; Eat (Hahn), Field-Mouse (Zschokke), and the Surinam Bat (Leydig). In_£eneral, the,differ ence_in habit aL soi^T^ide s^witb^di ffereuces in t he dimensions of the„pa4;a,&ite7-^4tkkaL t least authorizes the distinct ion ^oLyarieties. We have to mention : 1. Demodf;x of Man {D. foUicn/oruin, var. Iioiiiinis). — The female measures 380 /x long and 45 /x wide at the thorax ; the male is 300 //. long and 40 /x wide. The rostrum is a little longer than it is broad. The length of the rostrum and ccplialothorax combined forms nearly one-third the total length of the body. The ova are cordiform or fusiform, from 60 /x to 80 /x long, and 40 /x to 50 /i broad. The Demodex of Man lives in the sebaceous glands of the face, where it often remains without its presence causing the slightest trouble. When there are more than a dozen in a follicle, this becomes dilated and prominent, and forms a comedon. It is rare that acne of the face can be attributed to it. Gruby assures us that forty people out of sixty are infested with it ; but this proportion has generally appeared to be exaggerated. 2. Demodex op the Dog (D. folUciilormn, var. canis ; D. caninus Tulk). — The female measures 250 /x to 300 /x long, and 45 jx broad ; ACARIASES. 215 the male 220 jj. to 250 /x long, and the same width. The rostrum is nearly as long as it is broad ; and its length and that of the cephalo- thorax combined is a little less than half the total length. The ova are fusiform, and from 70 /x to 90 /a long, and 25 /a broad. This Deraodex causes follicular mange in the Dog. 3. Demodex of the Cat [D. foUiculorum, var. cati). — Similar to that of the Dog, but one-fourth smaller in all its dimensions. It was found by Leydig, in 1859, on the nose of a Cat affected with Sarcoptic scabies ; and by Meguin in the external auditory canal of two Cats. It appears to be inoffensive. Fig. 86. — De- 4. Demodex op the Goat {D. foUiculorum, var. modexfollimh- caprcB).—T\iQ female is 230 {x to 250 /i long, and 60 /x to ['J'-"^'j;^ ^;1^^> 65 /x broad ; while the male is 220 /x to 280 /x long, and mac-nmed one 50 /x to 55 /x broad. The rostrum and cephalothorax hundred dia- combined are nearly equal to half the total length. meters. — The ova are ellipsoid, and from 68 /x to 80 /x long, and Railhet. 32 fx to 45 fj. broad. It has been found by Niederhoeusern, EailHet and Nocard, and causes a pustular dermatosis which will be referred to hereafter. 5. Demodex of the Pig [D. folliculoyum, \nx. suia ; D. plujlloides Csokor). — The female measures 240 /x to 260 /x long, and 60 /x to 66 /x broad ; and the male 220 /x long, and 50 /x to 57 /x broad. The rostrum is very developed, and a little longer than it is wide ; its length and that of the cephalothorax is nearly equal to that of the abdomen. The eggs are ovoid, and a little contracted and elongated at the ends ; they are from 100 /x to 110 /x long and 30 /x wide (Fig. 89). This form determines a pustular affection on the Pig. 6. Demodex of the Sheep {D. foUiculorum, var. avis). — Found by Oschatz in the Meibomian glands of the Sheep ; it differs from that of Man chiefly in the greater length of its rostrum and cephalothorax. It has not been seen since Oschatz found it. 7. Demodex of the Ox {D. foUiculorum, var. bovis). — The average length is 200 /x. The rostrum and cephalothorax form about two- fifths of the total length. Eggs ovoid in shape. Causes a pustular affection on the Ox. 8. Demodex of the Horse {D. folliculormn, var. equi). — Found by E. Wilsoui in the product of secretion of the Meibomian glands of a Horse. He described it as identical with the Demodex of Man. In 1845. Gros also indicated the presence of the Demodex in the " mufle " of the Horse. A.— Demodecic Scabies of the Dog. Synonyms.— Follicular Mange, Bed Mange, Black Mange of the older veterinarians. History. — As has been stated, the parasitic nature of this disease was first recognised by Topping ; and Roll separated the affection from the other exanthemata of the Dog. Delafond and Bourguignon pointed out its gravity, and described it under the name of Acne Simonea. Verheyen proposed for it the designation of follicular mange, by which ^ Wilson. Transactions of the Veterinary Medical Association, 1843-44, p. 399. 216 TEEATISE ON PARASITIC DISEASES. name it is now almost exclusively known. It has been more especially studied by Gruby, Haubner, Gerlach, Sparks, Simonds, Oreste, Weiss, Friedberger, Lafosse, Saint-Cyr, Cornevin, Pennetier, Me^'uin, Laulanie, etc. Symptoms. — Follicular scabies presents itself under different aspects, according to its duration ; and to such an extent, that one might imagine them to be different diseases, if not informed as to this polymorphism. At the commencement, there are merely somewhat red depilations about the elbows, hocks, around the eyes, and at the toes ; and in the place of the hairs are seen small papules, with a pityriasic powder covering the parasitic patches. Gradually these depilations extend, become redder, and reach the inner surface of the paws and the cheeks ; the eyelids are swollen, inverted — entropion — and their borders are covered with an abundant purulent matter. The skin of the cheeks is thickened, depilated, wrinkled, and covered with papules and pustules more or less irritated. The pruritus, still intermittent, is more marked. The disease at last becomes generalized, occupying the entire surface of the body. The skin everywhere presents, in different degrees, the characters that it at first showed on the head. A crowd of acne pimples is scattered everywhere— sometimes confluent, sometimes discrete ; some yet in the papular stage, others pustular. Among the latter, a great number are dark-blue at their summit, and a sanguinolent serosity can be squeezed from them, in which the Demodex can be found on microscopical examination. These parasites are more numerous in the small pustules with apparently purulent contents, and in those which merely yield a kind of cyhnder of sebaceous fat on pressure. The number of Acarina is often pi'odigious, and constitutes the greater portion of the product under observation. More or less abundant crusts are noticed at various poiats, due to the rupture of the pustules and drying of their contents. At the parts most severely affected the skin is moist and cracked, and in the folds there is a yellow viscid matter ; the greater portion is depilated, and the animal exhales a foetid, sour odour that is absolutely nauseating. When the malady has arrived at this stage, it has produced a profound effect upon the whole organism ; the appetite — which was for a long time unimpaired, and even increased — now diminishes, emaciation begins, and this gradually goes on to marasmus. In certain cases, as Saint-Cyr has shown, ^ the disease is generalized, but it does not cause depilation except at some rather circumscribed points ; the pustules are rare, but they are irregularly disseminated everywhere, and the condition might be taken for one of generalized acne. In addition, the whole of the skin is covered with a fine dust, ^ Saint-Cyr. Oale folJicnlah-e. Journ. de Mtd. Veter. et de Zootechnie. Lyons, 1876, p. 327. ACAEIASES. 217 as if the animal had been powdered with maize flour. In the hairless places — whieh are more or less circular — there is much irritation, a serous exudation, excoriations, and even small sores. An interesting form is that which Saint-Cyr has named ' the cir- cinated form of follicular mange.' It consists of circular patches from 2 cm, to 6 cm. in diameter, red and inflamed — more particularly towards their slightly salient borders, depilated, and often — but not always — showing chiefly at their periphery small, red, pustular, aeneous pimples. In enlarging, these patches may join each other, and form others more extensive, with largely festooned borders. Often the centre becomes pale and covered with yellow dust. This circinated form is seen in the early stages, and it may be accompanied by the A Dog affected with advanced Demodecic Scabies. acneic form ; it is not very pruriginous, and the general health does not appear to be afi'ected. This form is related to that which Friedberger and Frbhner^ have designated the ' squamous form,' and which they give as of frequent occurrence. It is scarcely indicated by any other sign than shedding of the hairs and the abundance of epidermic pellicles. There is no humidity, and little, if any, trace of inflammation. The disease ^ Friedberger and Frohner. Lehrbuch der Spec. Pathcl. 2nd edit., I., 1889 ; French translation, I., 1891, p. 533. Thtr. der Hausthiere, 218 TREATISE ON TAKASITIC DISEASES. commences principally around the eyelids, and the eyes are surrounded by a depilated circle, which is somewt at red and scaly. This scabies may extend all over the body, and is often characterized by the deep tint of the patches, which are sometimes circular, as in the circinated form. There is usually no pruritus, and the diagnosis is difhcult — often necessitating a microscopical examination of the sebaceous matter. Course, Duration, Termination. — Follicular scabies pursues a very slow course, especially at the commencement. Its duration is long, and cases have been seen of a year's, two years', or even longer duration. It usually terminates in death, owing to its resistance to parasiticides. Weiss, ^ however, gives an instance of spontaneous recovery from this scabies of a pregnant bitch which aborted ; the pustules gradually disappeared, an abundant desquamation followed, the skin became smooth, and the Demodex could not be found. The animal, nevertheless, succumbed to the cachectic condition into which it had fallen. Diagnosis, Prognosis. — The circinated form may easily be mistaken for tinea tonsurans. However, in follicular scabies the hairs are not altogether absent ; while in tinea they are broken close to the skin, which appears as if shaved. The microscope shows on the surface of the epidermis the Tricliophyton to)tsumns if the malady be tinea ; but in scabies, scraping the skin to the blood and examining the products obtained will reveal the presence of the Demodex folUculoruin. A mistake may also occur with regard to sarccptic scabies ; but the chief points in the diagnosis of this have been already shown, and the microscope must decide in doubtful cases. The most frequent errors arise with respect to an erythematous skin affection of young Dogs, named red manyc (rouge^), which is distin- guished from follicular scabies by its being non-parasitic ; and instead of commencing, like the latter, on the paws and head, and of being acnei- form, it appears on the limbs, on the inner surface of the thighs and fore-arms, underneath the belly, and on those parts where the skin is fine and almost hairless. It is also characterized by the redness of the integument, which is more or less roughened and harsh, and is most frequently without vesicles or crusts. It is very pruriginous, and this increases the redness of the skin and induces artificial lesions, as a consequence of the rubbing and scratching. It must be remembered that demodecic scabies may co-exist with various cutaneous affections of youth, and with sarcoptic scabies and tinea tonsurans. The prognosis of follicular scabies is always very grave, parasiticide treatment rarely succeeding in destroying the Demodex. Pathological Anatomy. — The prominent feature in the pathological ^ Weiss. Repertorium der Thierheilkunde, 1860. -' M^gnin, Tia.sbot, Wtber. Soc. Centr. de Mt5d. Vi'terinaire (Recueil, 1882, p. 1270). ACAEIASES. 219 - -J ii''.:-^ — 8> anatomj' of this affection is the presence of the Demodcx folliculorum in the hair-foUicles and sebaceous glands ; but particularly in the former, where it is seen sometimes in considerable quantity. Gruby, with Delafond, has counted as many as 200 in one hair-fol- licle. They are seen to be pressed upon one another, the rostrum being directed towards the bottom of the follicle (Fig. 88), and the ventral surface ordinarily on the side of the hair or the space it should occupy. Here they are observed in all stages of development — from the eggs to the sexualized indi- viduals and fecundated females. By their presence they cause an irrita- tion which is manifested by signs of variable intensity, according to their number and activity. When the inflammation is acute, it extends around the hair-follicle or sebaceous gland, invades the tissue of the derma, and terminates in pyogeny and the formation of pustules. At other times, there is merely hyper- secretion of sebaceous matter, which dilates the canal of the follicle. According to Kruhkowski,i the Demodex, when they have been some time in their first location, pass through its walls into the derma and subcutaneous connec- tive tissue, causing— in the first instance — inflammation of the skin and the eruption of pustules on its surface ; and in the second, a small abscess and haemorrhage. The shedding of the hairs is due to the proliferation of cells on the internal surface of their folHcle, and soften- ing of their base. Eelapses are brought about by som.e of these 1 Krulikowski. Russian Veterinary Archives, St. Petersburg, 1879 -nJl t.- sa m 3 Fig. 88.— Section of the skin of a Dog affected with FolliculHr Scabies ; mag- nified forty diameters. — After Lau- lanie. e, epidermis continned to form the sheath of the hair - fttllicle /, which — sinuous, and bifid at the bottom — con- tains two hairs p, the bulbs of which are seen at bh' . At a, a', a", a'", a"", this follicle shows dilatations, due to the ac- cumulation of the Demodex d ; sb, seba- ceous glands, one of which, ,s6', contains the Demodex ; s, 1884 ; and Kevue Veterinaiie, 1885, p. 1. - Martemucci. DtrmatiU/olliculoha Uefitbinioniy Naples, 1866. ACAEIASES. 221 — then receiving a larger quantity of blood — have a greater vitality, and can therefore furnish a more abundant nourishment to the pre-existing Demodex ; hence their extraordinary multiplication. This authority also proposes to give it the name of follicular dermatitis, vphich — in his opinion — is more in accord with its inflammatory character. But these ideas are not well founded. No investigations have been made to establish the constant — or at least very frequent — presence of the Demodex in the skin of Dogs in good condition, as has been observed in Man ; and it would seem that Martemucci's notions are only a hazardous generalization of facts appertaining to human dermatology, the only support they receive being the difficulty in transmitting the disease ; though this can be explained by the deep, intra-cutaneous habitat of the parasites, and the necessity for a predisposition. The latter is to be found more especially in the youthfulness of the animals, for it rarely happens that adult creatures are attacked. Breed also plays an important part. L. Lafosse^ mentions that lap-dogs, before or after having paid their tribute to the disease of youth (dis- temper), are more frequently affected with follicular mange, although no breed is exempt. The observations of Cornevin- are — so far as breed is concerned — more in accord with what is usually remarked, that the disease is more frequent in short-haired than in long-haired Dogs. Accepting these predisposing causes, the efficient cause is contagion. But this is much less easy to produce than in the other kinds of scabies, owing to the deep situation of the parasite. Delabere-Blaine and Clater — quoted by Verheyen— assert that Dogs which cohabit for a long time with mangy ones, do not contract the malady, and that at other times the slightest contact will suffice to convey it. These differences may be explained by errors in diagnosis, the demodecic cause of follicular scabies not being known when the statements were made. Since that time instances have been reported in which con- tagion has not been effected, notwithstanamg every facility for its taking place. Weiss's patient lived from eight to fifteen days among other Dogs, without these contracting the affection. Eivolta has transferred the Demodex from a diseased to a healthy Dog without result. Martemucci has inoculated the healthy parts of the skin of a Dog with the fluid from pustules on diseased regions, and which was rich in parasites, and yet the result was negative. It has been the same with the experiments of Friedberger, who, besides, has not observed contagion occurring by making diseased Dogs associate with those which were healthy ; and the observations of Siedamgrotzky, made at the Dresden Veterinary School, and those of Csokor, carried 1 L. Lafosse. Traite ile Patholof/ie Viterinaire, II., 1861, p. 247. ^ Ch. Cornevin. Du Demodtx i'aninm et de la Maladk quil occamoiine, liyon?, 1868, p. 57. 222 TKEATISE ON PAKASITIC DISEASES. out at the clinic of the Vienna Veterinary School, are to the same effect. 1 On the other hand, Haubner- has succeeded in producing the disease by depositing demodecic pus directly on the skin of a healthy Dog ; for at the point where he placed the animalcuhe, in about twenty- four hours there was slight tumefaction of the skin ; in forty-eight hours the folhcles already contained a purulent fluid, in which young and adult acari, as well as ova, could be distinguished by means of the microscope. The exanthem extended, but the Demodex dis- appeared, and a spontaneous recovery took place. Cornevin made four inoculation experiments, and succeeded in one ; but here, also, in about eight days the malady vanished of itself. This authority mentions a somewhat striking instance of contagion from a nursing bitch to two of her puppies ; a third puppy remained free from the disease.'^ Of four Dogs — three of which were adults and the other smooth-haired, five months old — inoculated by Guinard, only one, the last-mentioned, contracted the disease.'* In fine, experiments and clinical observations demonstrate that the transmission of follicular scabies from Dog to Dog is very diffi- cult. Martemucci and Friedberger have in vain attempted to pass the Demodex of Man to the Dog. With regard to transmission of the follicular scabies of the Dog to Man, this has only been reported by Ziirn,^ who has seen a veterinary surgeon, a coachman, and a woman, who attended on Dogs so affected, suffer from a very pruriginous eruption on the hands and feet, the pustules which formed containing the Demodex. But these persons must have had a marked predisposition for the malady ; as for years, and daily, people have attended, and now attend, upon diseased Dogs without taking any precautions, and yet no cases of contagion are recorded. And Martemucci has unsuccessfully inoculated demodecic pus from a Dog on Man ; while Cornevin has failed to implant the disease on himself. Treatment. — Every known parasiticide substance has been tried for the cure of folhcular scabies of the Dog, but generally in vain ; as the parasites are deeply situated, beyond the reach of the remedies employed. There is no need to enumerate all the attempts which have ^ Rivolta. 11 Medico Veterinario, ISSf), p. 433. — Friedberger. Archiv f. Wis- pensch. u. Prakt. , Tiiierheilkunde, II., 1876, p. 25. — Siedamgrotzky. Bericht iiber das Veteriniirwesen in Sachseti, 1878. — Csokor. Ueber Ilaarnachnilben. (Esterr. Vier- teljahrsschrift, 1879, p. 138. - Haubner. Kepertoriuni der Thierheilkunde, XX., 1859, p. 81. (^ A similar instance occurred in my own experience when in the 2nd Life Guards. A valuable dachshund belonging to an officer was affected with follicular scabies when .suckling two pu])pies. both of which became infected and soon died.) ■* Guinard. .Journal de Mod. V^t^r. et de Zootechnie, 1890, ]>. o^^O. ^ Ziirn. Ueber Milbtn, etc. CEsterr. Landwirthschaftlichcr Wochenblatt, 1877. ACAKIASES. 223 been made to combat the malady ; so we will only indicate those which have had a good result, though they are exceptional.^ Balsam of Peru has been particularly recommended by Siedamgrotzky . It has been used diluted with four parts of alcohol, and rubbed into the skin every day, after the pustules have been squeezed, so as to remove their contents. By this means he says he has obtained a cure in a case of generalized scabies. Zundel also states that he has derived excellent results from this medicament, though it was more diluted. But the treatment is very expensive, owing to the long time it has to be continued and the care required ; for in simple cases, Fried- berger and Frohner have only been able to effect a cure after fifty-eight days' rubbings. On one occasion, after sixteen weeks' treatment of a Dog that was seriously affected, it was supposed to be cured ; but the disease soon reappeared when the remedy ceased to be applied. Brusasco's method consists in the employment of sulphurct of 'potass and cantharides ointment. Friedberger and Frohner assert that they have completely cured very advanced cases. The Dog being cHpped, a sulphur bath is administered, 500 grammes liver of sulphur to 100 litres of water. Then, for three days in succession, one-third of the body is dressed with an ointment composed of cantharides ointment 1 part, lard 6 parts. On the fifth or sixth day, the entire body is washed, and a few days afterwards the sulphur bath is again given, followed by the ointment as before, and so on until a cure is effected. But such a result is far from being constant ; for Friedberger and Frohner have failed in one case, after sixty-eight days' treatment, during which 12 sulphur baths wei-e administered, and 9 total applica- tions of the ointment, plus 9 partial applications. In any case, there is reason to apprehend dangerous irritation of the eyes ; so that it is advisable to employ the balsam of Peru for the parts surrounding them. Creolin should be tried. In strong solution — 30 to 100 — Reul has had a cure in a case of partial disease ; and the results of the trials of Guinard, with an ointment composed of creolin 5 parts and lanoHn 100 parts, are encouraging. But it must be noted that this treatment has not been successful in the hands of Watkins. Unterberger has succeeded with the essence of juniper applied with friction ; four applications were sufficient. Weiss recommends the same remedy. A writer in the Veterinary Journal for September, 1875, advises : creosote, 4 drams ; olive oil, 7 ounces ; solution of potass, 1 ounce. Mix the creosote and oil, then add the potass. One or two apphcations a week ^ Unterberger. Clinique de Dorpat (Journ. de Med. Veterinaire, Lyons, 1863, p. 125). — Brusasco. II Medico Veterinario, 1870. — The Veterinary Journal, September, 1875. — Zundel. Dictiounaire de Med., de Chit: et d'IIy