key: cord-021744-x320625f authors: Thompson, Mark S. title: Systemic Approach to Differential Diagnosis date: 2017-11-17 journal: Small Animal Medical Differential Diagnosis DOI: 10.1016/b978-0-323-49830-2.00002-0 sha: doc_id: 21744 cord_uid: x320625f nan Protein concentration is greater than 2.5 g/dL Nucleated cell count ranges from 400-10,000/mL Predominant cell type on cytology is the small lymphocyte (also see neutrophils, macrophages, plasma cells, and mesothelial cells) Triglyceride concentration of pleural fluid is greater than that of serum (definitive test) Signs of these two types of allergies are similar. Atopy tends to occur primarily in young adults, whereas food hypersensitivity can begin at any age. Atopy is usually seasonal at first but may become less seasonal. Causes MECHANISTIC • Secretory • Osmotic • Permeability (exudative) • Dysmotility • Mixed TEMPORAL • Acute • Chronic ANATOMIC • Extraintestinal • Small intestinal • Large intestinal • Diffuse PATHOPHYSIOLOGIC • Biochemical • Allergic • Inflammatory • Neoplastic ETIOLOGIC • Bacteria • Dietary • Fungal • Idiopathic • Parasitic • Viral CAUSAL • Exocrine • Thrombocytopenia-increased buccal mucosal bleeding time (BMBT), decreased platelet count (PLT), normal activated partial thromboplastin time (aPTT), normal prothrombin time (PT), normal fibrin degradation products (FDP) • Platelet dysfunction (e.g., aspirin treatment)-increased BMBT, normal PLT, increased aPTT, normal, PT, normal FDP • Intrinsic pathway defect (e.g., hemophilia A or B)-normal BMBT, normal PLT, increased aPTT, normal PT, normal FDP • Factor VII deficiency-normal BMBT, normal PLT, normal aPTT, increased PT, normal, FDP • Multiple factor defects (e.g., vitamin K antagonism)-normal BMBT, normal PLT, increased aPTT, increased PT, normal FDP • Common pathway defect (e.g., factor X deficiency)-normal BMBT, normal PLT, increased aPTT, increased PT, normal FDP • DIC-increased BMBT, decreased PLT, increased aPTT, increased PT, increased FDP • von Willebrand disease-increased BMBT, normal PLT, normal aPTT, normal PT, normal FDP Differential Diagnosis Acute onset of coughing, sneezing, nasal discharge, ocular discharge Low-grade fever Secondary commensal bacterial infections leading to mucopurulent discharge and productive cough May lead to pneumonia with high fever, inappetence, productive cough, and increased respiratory effort Variable incubation period, prodromal phase: nervousness, anxiety, paresthesia Progress to forebrain signs ("furious" form of rabies): irritability, restlessness, pica, photophobia, increased saliva production with decreasing ability to swallow, hyperesthesia progressing to incoordination, seizures, and death May also progress to "dumb" form: paralysis, lower motor disease, leading to coma, respiratory paralysis, and death PSEUDORABIES Suspected to be result from ingestion of infected raw pork Neurologic dysfunction: ataxia, abnormal papillary light response, restlessness, trismus, cervical rigidity, ptyalism, tachypnea, excoriation from pruritus of head and neck; vomiting, diarrhea; most dogs die within 48 hours Hacking cough with gagging, easily elicited with tracheal palpation; cough may be paroxysmal, usually subsides within 7-10 days, and may lead to secondary bacterial or mycoplasmal infection • BUN/creatinine-increased in 50%-65% of dogs and in 33% (Cr) and 57% (BUN) in cats. Usually prerenal due to dehydration and hypotension. May be secondary to intrinsic renal failure (sepsis and immune-complex). • Potassium-decreased in 20% of cases in dogs and 56% in cats. Increased loss in vomiting and due to renal loss with fluid therapy plus reduced intake and aldosterone release caused by hypovolemia. • Sodium-can be increased, decreased, or normal. Increase usually caused by dehydration, decrease caused by losses secondary to vomiting. • Calcium-commonly decreased in cats, rarely in dogs, rarely increased in both dogs and cats. Reduction is a poor prognostic indicator in cats, but has no prognostic significance in dogs. May be caused by saponification in peripancreatic fat and glucagon release stimulating calcitonin. • Chloride-very commonly decreased in dogs. Loss in GI secretions in vomiting. • Phosphate-often increased in dogs; uncommonly increased or decreased in cats. Increase usually due to reduced renal excretion secondary to renal compromise. Decrease (in cats) due to treatment for diabetes mellitus. • Glucose-increased in 40%-88% of dogs and decreased in up to 40%. Increased in 64% of cats, rarely decreased. Increase due to decreased insulin and increased glucagon, cortisol, and catecholamines. Decrease caused by sepsis or anorexia. • Albumin-increased in 39%-50% and decreased in 17% of dogs. Increased in 8%-30% and decreased in 40% of cats. Increase due to dehydration. Decrease due to gut loss, malnutrition, concurrent hepatic disease, or renal loss. • Hepatocellular enzymes (ALT, AST)-increased in 61% of dogs and 68% of cats. Hepatic necrosis and vacuolation due to sepsis, local effects of pancreatitis +/-concurrent hepatic disease in cats. • Cholestatic enzymes (ALP and GGT)-increased in 79% of dogs and 50% of cats. Biliary obstruction due to acute or chronic pancreatitis +/-concurrent cholangitis +/-lipidosis in cats; steroid-induced ALP in dogs. • Bilirubin-increased in 53% of dogs and 64% of cats (same causes as GGT and ALP). • Cholesterol-increased in 48%-80% of dogs and 64% of cats. Can be due to cholestasis; unclear if cause or effect. • Triglycerides-commonly increased in dogs. Unclear if cause or effect. • Neutrophils-increased in 55%-60% of dogs, increased in 30% and decreased in 15% of cats. Increased due to inflammatory response. Decreased in some cats due to consumption, may be a poor prognostic indicator. • Hematocrit-increased in about 20% and decreased in 20% of both dogs and cats. Increased due to dehydration and decreased due to anemia of chronic disease or gastric ulceration. • Platelets-commonly decreased in severe cases in dogs. Decreased due to circulating proteases +/À DIC. Failure of normal closure of neural tube: vary in severity from clinically inapparent (agenesis of corpus callosum) to severe (anencephaly) Lissencephaly: failure of normal migration of neurons in development of cerebral cortex; leads to abnormal appearance of sulci and gyri (most often seen in Lhasa Apso) Cerebellar hypoplasia: seen most often in cats after in utero panleukopenia infection; rarely seen with parvovirus infection of developing cerebellum in dogs; may be isolated malformation without infection Chiari-like malformations: protrusion of cerebellar vermis through foramen magnum (Cavalier King Charles Spaniel, other dog breeds) Hydrocephalus: congenital hydrocephalus seen most often in toy and brachycephalic breeds; suggests hereditary basis; often congenital stenosis or aplasia of mesencephalic aqueducts • Confirm and remove small uroliths from bladder or urethra. • Obtain uroliths for quantitative analysis and culture. • Retrieve uroliths from bladder or urethra using stone forceps or stone basket. • Fragment uroliths with laser lithotripsy. • Fill bladder before and after voiding urohydropropulsion to remove small uroliths. should be bilaterally symmetric, have a smooth and regular surface, have soft parenchyma, and not be painful to touch. • Radiography of limited value for providing an actual diagnosis but may provide information about size, shape, contour, and location of the prostate. Prostatomegaly may cause dorsal displacement of the colon and cranial displacement of the urinary bladder. Mineralization with neoplasia, bacterial prostatitis, and abscessation may be apparent. • Prostatic ultrasound is the most useful and practical imaging method. Normal prostate should have smooth borders and homogenous parenchymal pattern of moderate echogenicity. Ultrasound also offers the opportunity for guided aspirates and core biopsy sampling for culture, cytology, and histopathology. • CT and MRI can evaluate size, shape, and homogeneity of prostate and allow evaluation of intrapelvic lesions, metastatic spread, and ureteral obstruction. • Definitive diagnosis requires cytologic, histologic, or bacteriologic evaluation of a prostate sample. Samples can be obtained using procedures such as semen collection, prostatic massage and wash, brush technique, fine needle aspiration, and biopsy. • Stop use of nephrotoxic drugs. • If proteinuria is insignificant (trace to 1 + dipstick reading and urine specific gravity >1.035), there is no need for further workup. • Perform urinalysis to exclude hemorrhage, infection, or inflammation as cause of proteinuria. If these conditions are present, do urine culture. If these conditions are not present, do urine protein/creatinine ratio. • Perform serum chemistry and CBC. Evaluate serum albumin and globulin. • Marked proteinuria ratio (UP/UC >3) with quiet sediment and normal globulins or a polyclonal gammopathy is consistent with renal glomerular disease (glomerulonephritis, amyloidosis). Rule out causes of glomerulonephropathy such as heartworm disease, hepatozoonosis, immune-mediated diseases such as SLE, chronic infectious diseases such as borreliosis, FeLV, FIV, ehrlichiosis, other chronic inflammatory diseases, neoplasia, and hyperadrenocorticism. • If no underlying disease found, may need renal biopsy to assess for glomerulonephritis or amyloidosis • Proteinuria detected by precipitation testing but not dipstick or proteinuria associated with a monoclonal gammopathy may be caused by Bence Jones proteins. This requires a search for osteolytic or lymphoproliferative lesions. Ehrlichiosis may mimic myeloma. If Ehrlichia negative, protein electrophoresis in indicated. A monoclonal gammopathy suggests myeloma. Clinical Findings, Dogs AFAST as an extension of the physical exam DH VIEW • DH and CC views are most common positive sites in lowscoring dogs and cats. • Useful for detecting pericardial effusion (racetrack sign) and pleural effusion • Advantage: less air interference than transthoracic TFAST views • Assessment of the weak or collapsed patient's volume status by observing dynamics of caudal vena cava (CVC) as it passes through diaphragm • May be indicative of right-sided heart failure, pericardial effusion/tamponade in acute collapse/weakness • May be indicative of volume overload, third spacing, primary gallbladder disease, and pancreatitis in the less acute patient • Liver masses, cysts, and diffuse or irregular changes in echogenicity may be appreciated • Least gravity-dependent view where air would rise to (pneumoabdomen) and fluid only at this site may be retroperitoneal rather than intraabdominal • Acoustic window into the abdominal and retroperitoneal space for free abdominal fluid and retroperitoneal fluid • Splenic masses and diffuse or irregular changes in echogenicity may be appreciated. • Left kidney may appreciate variety of pathology, including hydronephrosis, pyelectasia, cortical cysts, perinephric cysts, masses, mineralization, calculi, and mineralization. • May be able to also see right kidney in small dogs and cats through the SR view • CC and DH views are most common positive site in low-scoring dogs and cats. • Urinary bladder may appreciate variety of lesions such as calculi, masses, wall thickening/abnormalities, and emphysema. • Spleen and small intestine most often visible here • Splenic masses and diffuse or irregular changes in echogenicity may be appreciated. • Small intestine pathology may be appreciated, including dilated loops (ileus, obstruction), wall thickening, masses, and related lymph nodes. • The name of this view is a misnomer because the liver and right kidney are not typically imaged. • Liver and right kidney are normally not present at the level of the umbilicus unless they are enlarged. • Stomach is not visible at the level of the umbilicus unless it's distended. • The HR umbilical view completes AFAST and is likely the region to perform abdominocentesis in higher-scoring dogs and cats. • Patients may be positioned in right or left lateral recumbency, especially if TFAST exam PCS views immediately follow the AFAST exam in stable patients, and in respiratorycompromised patients, and for the chest tube site (CTS) view; sternal recumbency or standing positioning is safer and preferred for the entire TFAST examination. • Ultrasound probe is placed in five positions: 1. Diaphragmatico-Hepatic (DH) view-immediately caudal to the xiphoid (same as AFAST DH view). Useful for detecting pericardial effusion (racetrack sign) and pleural effusion. Left and right CTS views-at the level of the seventh to eighth intercostal spaces at the highest point, upper third of the thorax, where lung may be visualized on the dorsolateral thoracic wall in the absence of pneumothorax, and where the cap of air would rise in the presence of pneumothorax • If evidence of lung against the thoracic wall is observed sonographically, then pneumothorax is effectively ruled out. • If there is no evidence that lung is against the thoracic wall, then the lung point is searched for where the transition zone is between pneumothorax and lung recontacting the thoracic wall. 3. Left and right PCS (pericardial site) view-over the heart at the level of the fifth and sixth intercostal spaces in gravity-dependent regions of the thorax • PCS views are used for quick assessment of lungs, heart, pleural, and pericardial spaces. TFAST as an extension of the physical exam • Part of both AFAST and TFAST examinations-see AFAST DH view • Useful for sonographic confirmation of pleural effusion and pericardial effusion (racetrack sign) • Less air interference than TFAST transthoracic PCS views, liver and gallbladder provide acoustic window into thorax • Allows for assessment of volume status by observing dynamics of the caudal vena cava (see DH view in AFAST as an extension of exam). • The most recent, most accurate described methodology by the originator of the Vet BLUE is to begin by finding the transition zone in a standing (or sternal) patient at the CTS/Cd view where abdominal contents and lung are viewed over an intercostal space, then sliding toward the head two intercostal spaces to begin the Vet BLUE at the Cd view (point 1). • From the Cd view (point 1) draw an imaginary line to the elbow. Halfway from the Cd to the elbow is the Ph view (point 2), and at the elbow is the Md view (point 3) and then in the axillary area as the final Cr view. If the heart is in view at the Md, slide the probe directly dorsally until over lung for the Md view, and define the Cr view by finding the transition of lung and thoracic inlet, then sliding caudally over the first two intercostal spaces. If a gator sign orientation is not observed, then you cannot be assured lung is being imaged. Vet BLUE lung ultrasound findings in progression from most to least aerated/most consolidated • Dry lung-glide sign with A-lines (reverberation artifact) at lung line indicates dry lung at the lung periphery. The confounder: A-lines with no glide sign consistent with pneumothorax • Wet lung ULRs (also called B-lines)-hyperechoic streaks that oscillate with respiration and extend to the far field, obliterating A-lines • Shred sign-deviation of the lung line (pulmonary-pleural line) and within the deviation hyperechoic foci of air movement seen in bronchi. Comparable to a radiographic air bronchogram. Indicates lung consolidation/infiltration. • Tissue sign-more severe consolidation/infiltration where no air movement is present. Referred to as hepatization of lung. • Nodule sign-anechoic round (nodule) often with a hyperechoic far border and acoustic enhancement through the far field as a ULR. Vet BLUE differential diagnosis for patients with respiratory signs with dry lung in all fields • Upper airway disease (laryngeal paralysis, collapsing trachea) • Airway obstruction (mass) • Feline asthma • Chronic obstructive pulmonary disease • Pulmonary thromboembolism • Centrally located lung lesion away from lung line, therefore missed by Vet BLUE Uveitis Differential Diagnosis in the Dog and Cat SYSTEMIC INFECTION Bacterial • Bacteremia or septicemia (d, c) • Bartonellosis (d, c) • Leptospirosis (d) • Borreliosis (d) • Brucellosis (d) Rickettsial • Ehrlichiosis (d, c) • Rocky Mountain spotted fever (d) Viral • Canine adenovirus-1 (d) • FeLV (c) • FIV (c) • FIP (c) Histoplasmosis (d, c) • Coccidiomycosis (d, c) • Cryptomycosis (d, c) • Aspergillosis (d) Algal • Protothecosis Parasitic • Aberrant nematode larval migration • Toxocara (ocular larval migrans) (d, c) • Dirofilaria larvae (d) Leishmaniasis (d, c) Immune-Mediated Uveitis • Idiopathic anterior uveitis (d, c) • Lens-induced uveitis (d, c) • Canine adenovirus vaccine reaction (d) • Uveodermatologic syndrome (d) (primarily Akita and Arctic breeds) primarily Golden Retrievers) mammary tumors • Mixed tumors (fibroadenomas) • Adenomas • Mesenchymal tumors • Malignant mammary tumors • Solid carcinomas • Tubular adenocarcinomas • Papillary adenocarcinomas • Anaplastic carcinomas • Sarcomas (rare) • Most feline mammary tumors are adenocarcinomas BB pellets or shot may be confused with small mammary masses) Prostatic Disease Differential Diagnosis Benign prostatic hyperplasia (BPH) Acute prostatitis Chronic prostatitis Abscess Cyst Prostatic neoplasia • Adenocarcinoma most common • Transitional cell carcinoma second most common • Urothelial carcinoma • Primary and metastatic hemangiosarcoma • History of lower urinary tract signs, penile discharge, hematuria, dysuria, tenesmus, obstipation, ribbon stools, stiff gait. Severe systemic signs suggest sepsis or systemic inflammation raises suspicion of acute prostatitis • Digital rectal examination along with caudal abdominal palpation is a noninvasive initial screening test. The prostate Acquired • Toxic (Escherichia coli endotoxin) • Drugs (glucocorticoids, chemotherapeutics) • Metabolic disease (hypokalemia, hypercalcemia) • Tubular injury or loss Active urine sediment • Good body condition • Hyperkalemia (if oliguric) • Normal to increased hematocrit • Enlarged kidneys • Potentially severe metabolic acidosis • Severe clinical signs for level of dysfunction • Normal-sized parathyroid glands (ultrasound appearance) CHRONIC RENAL FAILURE • History of previous renal disease • History of polyuria/polydipsia • Small irregular kidneys • Nonregenerative anemia • Normal to hypokalemia • Normal to mild metabolic acidosis • Inactive urine sediment • Weight loss/cachexia • Mild clinical signs for level of dysfunction • Enlarged parathyroid glands Calculi (nephroliths or nephrolith fragments that have migrated into the ureter) Acute Pain Preemptive Scoring System (examples in each category) Chronic Pain Assessment Acute Pain Assessment Subjective evaluation of pain in animals relies on observation and interpretation of animal behavior. Pain may be indicated by loss of normal behaviors or appearance of abnormal behaviors thrashing • Lethargic, withdrawn, dull, obtunded • May ignore environmental stimuli • Abnormal sleep-wake cycle, inability to sleep • May bite, lick, or chew painful area • Adopt abnormal body positions to cope with pain, hunched posture, "prayer position" • Abnormal tail position • Lameness, abnormal gait • Anorexia, reluctant to eliminate • Ears held back, eyes wide open with dilated pupils or closed with a dull appearance • Disuse or guarding of painful area • Vocalization • May become more aggressive and resist handling or palpation or may become more timid and seek increased contact with sit very quietly, and pain may be missed by those looking for more active signs of pain Acute Pain Preemptive Scoring System (examples in each category) Minor Procedures: No Pain • Physical examination, restraint • Radiography • Suture removal, cast application, bandage change Moderate Surgeries: Moderate Pain • Ovariohysterectomy, castration, caesarean section Major Surgeries: Severe Pain • Fracture repair, cruciate ligament repair • Thoracotomy, laminectomy, exploratory laparotomy • Limb amputation • Ear canal ablation Chronic Pain Assessment Clinical signs of chronic pain depend on underlying cause and pathologic state. in treatment (e.g.,osteoarthritic dog that experiences acute pain after excessive strenuous activity) examinations (Focused Assessment with Sonography for Trauma Rule-outs include: • Right-sided volume overload • Pulmonary hypertension • Right-sided heart failure • Dilated cardiomyopathy 2. An attenuated CVC with little variability in its diameter supports a low CVP and hypovolemia; CVC is flat • Rule-outs include causes of profound hypovolemia, including hypovolemia and distributive shock The CVC normally has a change in its diameter of between 30% and 50%; in the ballpark of normal with a "bouncing" appearance • Gallbladder is often adjacent the diaphragm on DH view • May be displaced by an enlarged liver • May be difficult to image with diaphragmatic hernia or gallbladder rupture, calculi/mineralization, or emphysema • Feline gallbladders are more difficult to image on DH view. • Gallbladder wall edema Used to visualize the heart, pericardial space, and pleural space • Assess for pericardial or pleural effusion combining with the DH view Increase depth so that the heart is seen in its entirety to avoid false positives from mistaking right ventricle/other heart chambers for effusion views: left ventricular short axis view to assess volume status and contractility; long axis four-chamber view to assess for right-sided conditions thoracic surgery, lung lobe aspirate, thoracoscopy, tracheal wash, thoracentesis Probe is positioned as described at the TFAST CTS view but then moved through three more views bilaterally • Vet BLUE has eight total acoustic views (four views bilaterally) Cd (caudodorsal lung region)-same as TFAST CTS view, upper third of the thorax at the level of the eighth to ninth intercostal spaces directly above the xiphoid near the highest point where lung may be visualized on the dorsolateral thoracic wall Ph (perihilar lung region)-sixth to seventh intercostal space, middle third of the thorax Md (middle lung region)-fourth to fifth intercostal space, lower third of the thorax Cr (cranial lung region)-second to third intercostal space GFAST Triad for volume status and patient monitoring GFAST, the name for the use of AFAST and its fluid scoring system, TFAST and Vet BLUE combined, may be used for rapid patient volume status assessment during, before, and after fluid resuscitation • Characterization of CVC and hepatic veins for estimation of CVP (see earlier); forms of shock (e.g., hypovolemic/distributive shock/cardiogenic/obstructive shock) • TFAST-assessment of cardiac views for volume and contractility, right-and left-sided conditions (see TFAST) • Vet BLUE-presence of wet lung screens for left-sided cardiac overload, and the pattern-based approach and Vet BLUE lung ultrasound signs help determine CHF, pneumonia, neoplasia, granulomatous conditions, PTE (pulmonary thromboembolism), and others FAST Ultrasound edited by Gregory R. Lisciandro, DVM, Dipl. ABVP, Dipl. ACVECC of Hill Country Veterinary Specialists, FASTVet.com and editor of textbook Focused Ultrasound Techniques for the Small Animal Practitioner Amphotericin B Ethylene • Patients are placed in either lateral recumbency; right is preferred because the basic echo views, gallbladder, caudal vena cava, left kidney are more easily imaged. Dorsal recumbency should not be used because of increased patient respiratory and hemodynamic stress. Ultrasound probe is placed in four regions of abdomen:1. Diaphragmatic-Hepatic (DH) view-at the level of the xiphoid, images the diaphragm, liver, gallbladder, caudal vena cava, pleural space, pericardial space, and lung 2. Spleno-Renal (SR) view-images spleen, left kidney, abdominal and retroperitoneal space 3. Cysto-Colic (CC) view-images bladder; however, an airfilled colon can confound imaging 4. Hepato-Renal (HR) Umbilical view-images small intestine and spleen • Probe is fanned in longitudinal (sagittal); transverse is not necessary • Purpose is quick assessment of AFAST target organs and detection of free abdominal and retroperitoneal fluid. Blood rapidly defibrinates in blunt trauma and nontrauma so it is seen as anechoic black triangulations. Penetrating trauma is different initially because blood often clots and blends in as soft tissue. Abdominal fluid score (AFS) BLUNT TRAUMA (THINK MEDICAL FIRST)• AFS 1 and 2 are major injury, small volume bleeder-no blood transfusion needed, not expected to be anemic (PCV >35%) if intraabdominal bleeding only. Reassess by AFAST and AFS (abdominal fluid score) to monitor for changes minimally 4 hours postadmission and sooner if unstable. If AFS stays 1-2 but PCV drops, look for bleeding at another site (retroperitoneal, pleural space, fracture site, external). • AFS 3 and 4 are major injury, large volume bleeder (AFS [3] [4] or becomes . Expect anemia (PCV <35%), use graduated fluid therapy (one third shock dose) and repeat titrated fluid challenges needed. With severe anemia (PCV <25%) blood transfusion is often necessary, and surgery uncommon. • Blood from ripping, tearing, crushing tends to clot, making it blend with adjacent tissue and difficult to detect by AFAST. With time clotted blood will defibrinate and become visible as black anechoic triangulations. Serial exams are key and should be performed as often as needed until certain the patient is medical and not surgical. • AFS 3 and 4 initially or on serial exams need surgical ligation of bleeding. • AFS 1 and 2 that stays 1 or 2 with serial exams is not surgical. • AFS 3 and 4 that are not anemic still need surgical exploration; waiting may lead to need for transfusion and additional risk and expense. Nontraumatic hemoabdomen (variably medical and surgical) • Bleeding intraabdominal tumor, spleen most common, PCV generally low normal or low. Surgical problem. • Useful for ruling out pneumothorax and for surveying for lung lesions. • Probe is placed perpendicular to the long axis of the adjacent ribs in order to image the intercostal space • The orientation obtained is referred to as the gator (alligator) sign from the image created by rounded rib heads as the gator's eyes and the intercostal space, a white line, as the gator bridge of its nose, likened to a partially submerged alligator peering at the sonographer. • Glide sign-normal to-and-fro motion of lung along the intercostal space or more specifically the movement of parietal and visceral pleural ruling out pneumothorax. Absence of the glide sign suggests pneumothorax. • Ultrasound lung rockets (ULR, also called B-lines)-hyperechoic streaks that extend from pleural line through the far field that oscillate like a pendulum in synchrony with respiration 1. Trauma-associated ULRs immediately rule out pneumothorax at that level of the thorax and support lung contusions until proven otherwise. 2. In nontrauma ULRs (also called B-lines) represent various forms of alveolar-interstitial edema, including left-sided CHF, hemorrhage, variety of pneumonias, inflammation, as more common causes (see Vet BLUE) • Step sign-deviation from the expected linear pulmonarypleural interface 1. Chest wall trauma or disease (intercostal tears, fractured ribs, subpleural hematoma) 2. Pleural space disease (effusion, diaphragmatic hernia, masses) • Lung point-location or transition zone at which collapsed lung secondary to pneumothorax recontacts thoracic wall 1. Move probe ventrally to middle, then ventral or lower third of the thorax with patient standing or sternal until evidence of lung against the thoracic wall is found, then move incrementally dorsally until lung is lost to determine the exact lung point 2. Use the lung point to assess and monitor pneumothorax; upper one third trivial to mild; middle one third is moderate; lower one third is severe.