Correct: This is a classic image of osteosarcoma, a COMMON, aggressive bone tumor typically found in the appendicular skeleton, especially distal radius.
Here is a memory aid for common locations of osteosarcoma - "Away from the elbow, near the knee". 90% have microscopic metastases to lungs by time of Dx, (but less than 10% will have visible thoracic metastasis at time of diagnosis).
Usually, does not cross joint (unlike osteomyelitis, which usually DOES cross joint). Look for soft tissue swelling, periosteal proliferation, sunburst periosteal reaction (33%), possible pathologic fractures.
D. Treat affected heifers with Ivermectin, repeat in 6 months
Correct: Avermectins (macrocyclic lactones), such as ivermectin, are the most consistently effective of these choices against all stages, including hypobiotic larvae, of Ostertagia, the parasite in this calf's gastrointestinal tract. An abomasum with a cobblestone or "Moroccan leather" appearance is pathognomonic for Ostertagia , one of the three stomach worms of cattle. In order to minimize the development of anthelmintic resistance, current recommendations for parasite control include not only appropriate deworming, but adequate nutrition and rotation of treated stock to "clean" pastures. Targeted selective treatment, or the deworming of only the most severely affected individuals in a group, is supported by some experts. Amprolium is your treatment of choices for calves and cows with Coccidiosis.
Correct: It is 48%. The trick with this kind of question is to pick an imaginary number of animals that you test, like 1000, and fill out your 2x2 table from there. If prev is 5% then there must be 50/1000 cats with FeLV and 950 cats that are disease-free.
A 90% sensitive test will correctly call 45/50 positive (box "a"), and IN-correctly call 5/50 negative, (box "c": these are the false negs).
If 50/1000 animals are infected, then 950/1000 are disease-free. Your 95% specific test will correctly call 902/950 disease-free (box "d": 0.95 X 950=902) and IN-correctly call 48/950 positive, (box "b": these are the false pos).
Now your a,b,c,d boxes are all filled, it is easy to calculate PVP =a/(a+b)=45/(45+48)=48%
Correct: MCF virus is ovine herpes virus-2 (OvHV-2) and is carried by 95-99% of sheep in North America which show no symptoms. It is also carried by 75% of domestic goats, 40% of muskox, 37% of bighorn sheep, 25% of pronghorn antelope, 62% of mouflon sheep, and by a small percentage of elk, mule deer, and white tailed deer. Susceptible hosts include cattle, water buffalo, deer, pigs, and bison; bison are the most susceptible
C. Acer rubrum (red maple)
Correct: Ingestion of Acer rubrum (Red maple) is most likely the cause of hemolytic anemia and the resultant pathology in this horse. Wilted or dry leaves and bark of red maple trees contain oxidants which damage red blood cell (RBC) membranes, resulting in the formation of Heinz bodies and eccentrocytes. Acute intravascular hemolysis, hemoglobinemia, methemoglobinemia, hemoglobinuria, and methemoglobnuria follow. Clinical signs of toxicity include: weakness, depression, tachypnea, tachycardia, icterus, cyanosis, and brown discoloration of blood and urine. Post mortem findings include: icterus, splenic hemosiderosis, splenomegaly, swollen dark red-blue black kidneys with red-brown tubular casts, and a swollen brown liver. Toxicity is often fatal. If the horse survives the hemolytic crisis, renal failure may develop due to pigmenturia.
Treatment is supportive care: IV fluids, oxygen, and blood transfusions.
Which of the following correctly describes placement of the electrodes when performing an electrocardiogram on a dog or cat? (note arms = forelegs, legs = rear legs)
A. White on left arm, black on right arm, red on right leg
B. White on right arm, black on left arm, red on left leg
C. Red on right arm, green on left leg, black on left arm
D. Black on right arm, white on left leg, red on right leg
E. Red on left leg, green on right arm, black on left arm
D. Pasteurella multocida
Correct: Pasteurella multocida infection in conjunction with Mycoplasma hyopneumoniae causes exudative bronchopneumonia, polyarthritis, and chronic lung lesions. Mycoplasma hyopneumoniae, (also called "Enzootic pneumonia") is a common, smoldering low-level illness. Stressors (parasites, other infections, even weather) can result in severe pneumonia. Best managed by decreasing stressors with improved ventilation and decreased overcrowding. In endemic herds, ABX for sick individuals (ie: lincomycin, tylosin, tiamulin, or a tetracycline) helps control illness, most likely by preventing secondary bacterial infection (like Pasteurella). Bacterin vaccines give good protection, decrease signs (coughing). Pre-farrowing vaccination of sows decreases colonization in suckling piglets.
C. Furosemide and enalapril
Correct: The radiograph here shows a severe symmetrical alveolar pattern in the perihilar region extending to the right and left caudal lung lobes. The heart is tall on the lateral view causing dorsal elevation of the trachea.
This, in conjunction with the physical findings, is compatible with left congestive heart failure (CHF) secondary to mitral valve regurgitation. The dog also has hepatic congestion evident by enlargement on the radiograph. Treatment for CHF include diuretics (furosemide/Lasix, hydrochlorothiazide, spironolactone), arterial vasodilators (enalapril, benazepril, amlodipine, hydralazine), positive inotropes (pimobendan), and venodilators (nitroglycerine).
Clavamox and enrofloxacin are antibiotics which could be used to treat pneumonia, but that is not this dog's problem. Immiticide is the treatment for heartworm. Atenolol is a beta blocker and not part of the management of mitral regurgitation or CHF. Atropine or a pacemaker would be indicated for conduction problems.
E. Miosis, protruding nictitans, enopthalmos, ptosis
Correct: Remember "My 3rd Sunken Toe"
(Miosis, 3rd lid protrudes, Sunken eye, Ptosis) and "sweaty horses".
A syndrome, not a disease per se. Can see 4 things with Horner's, ALL associated with the eye:
1. MIOSIS (constricted pupil-lose sympathetic innervation)
2. PROTRUSION 3rd eyelid (nictitans)
3. ENOPHTHALMOS (sunken eye)
4. PTOSIS (drooped eyelid), +/- anisocoria
Below: dog with Horner's Syndrome OS (left side)
Anhidrosis (dry, decreased sweating ipsilaterally) occurs in all animals EXCEPT horse, but difficult to observe. PARADOXICALLY, Horses can show profuse sweating ipsilaterally due to loss of peripheral vasoconstriction.
It is your first day on the job and your boss says there is a dog in room two with Horner's syndrome.
Which four signs correctly constitute Horner's syndrome?
A. Sweating ipsilaterally, exopthalmia, sunken nictitans, mydriasis
B. Dry eye ipsilateral, miosis, sunken nictitans, exophthalmos
C. Proptosed nictitans, lip deviated ipsilaterally, miosis, anhidrosis
D. Protruding nictitans, bupthalmia, ptosis, mydriasis
E. Miosis, protruding nictitans, enopthalmos, ptosis
Correct: Parvovirus. Expect to see intestinal crypt necrosis, lymphoid depletion of Peyer's patches, shortened, blunt villi and collapse of the lamina propria with canine parvovirus. Puppies with parvo are severely neutropenic and lymphopenic which may help you remember that feline panleukopenia is ALSO caused by a parvovirus.
Think of canine distemper with intracytoplasmic eosinophilic inclusion bodies, catarrhal enteritis and mucopurulent oculonasal discharge.
Canine adenovirus-1 is the causative organism of infectious canine hepatitis.
Picture of necrosis and lymphoid depletion of Peyer's patches
NOTE: If you hear of necrotic Peyer's patches from necropsy of a cow with severe diarrhea, stomatitis and fever think of the foreign disease, rinderpest. In 2011, the United Nations Food and Agriculture Organization (FAO) and the World Organisation for Animal Health (OIE) officially declared that rinderpest was eradicated globally. But because it is a classic, severe, reportable, stomatitis-type disease, it's unlikely that vets will be allowed to forget rinderpest on DDXs for years.
Correct: hypothyroidism. The clinical signs, physical exam findings, and lab work abnormalities are classical for hypothyroidism. Other common abnormalities seen with hypothyroidism include pyoderma, neuromuscular signs (ataxia, knuckling, vestibular signs, etc), markedly elevated triglycerides, and a mild normocytic, normochromic anemia. Hyperthyroidism rarely occurs in dogs. You would expect to see polyuria, polydipsia, and polyphagia with hyperadrenocorticism.
A. Cauda equine neuritis, herpesvirus myelonencephalopathy
Correct: Horses with cauda equina neuritis (also called polyneuritis equi) have a progressive symmetric LMN paresis of the tail, bladder, rectum, anal sphincter.
Look for urinary incontinence, fecal retention, and a weak or paralyzed tail. May see hind limb paresis if lumbosacral spinal cord is affected.
Cranial nerves can also be affected, but typically cranial involvement is asymmetric. May see temporal or masseter atrophy (cranial nerve 5), facial paralysis, and exposure keratitis (cranial nerve 7), head tilt, or other CNS signs. Cause is unknown, may be an autoimmune process. Grave prognosis. Eventually euthanized.
Herpesvirus myeloencephalopathy (EHV-1) may also present with urinary incontinence, but this is a relatively uncommon manifestation of equine rhinopneumonitis.
You would expect to hear a history of the more common EHV signs in other horses from the same farm, like respiratory disease ("snots") in foals and abortions in mares.
Bracken fern toxicity (Pteridium aquilinum) causes thiamine deficiency in monogastrics (like horses) and bone marrow depletion, aplastic anemia, and bladder tumors in ruminants.
In horses, look for signs of anorexia, weight loss, incoordination, and a crouching stance with feet placed wide apart. Horses may have trembling muscles when forced to move.
A 7-year old male intact Chesapeake Bay Retriever presents to your clinic with the presenting complaint of an intermittent cough. On exam, the dog is bright and alert with a temperature of 100.5F (38.1 C), heart rate of 110 beats per minute and respiratory rate of 30 breaths per minute. You perform chest radiographs which are shown below. A CBC shows a hematocrit of 39% (35-57%), neutrophil count of 8,659/ul (2,900-12,000/ul), monocyte count of 984/ul (100-1,400/ul) and eosinophil count of 1,980/ul (0-1,300/ul). What is the treatment of choice for the most likely diagnosis?
E. Colitis X
Correct: This is the clinical picture of colitis X, a lethal diarrheal disease of horses with an acute to peracute-onset.
The specific cause is unknown, but infectious and toxic etiologies are most likely. Anaphylaxis also produces similar intestinal lesions.
Look for signs of shock, peracute severe diarrhea and a packed red cell volume (PCV) above 65%, and sudden death.
Some cases may die before diarrhea is seen.The cause is unknown but stress (like transport) or surgery often precedes disease. This is a diagnosis of exclusion.
If other potential causes of peracute diarrhea such as Salmonellosis, Potomac horse fever (PHF), Clostridial enterocolitis, cantharidin toxicity, etc., are ruled out, you are left with Colitis X.
This is not likely to be NSAID-associated right dorsal colitis due to the distribution of lesions seen at necropsy and the minimal amount of NSAIDs the horse had received (and not recently).
A. Administer ivermectin twice annually, once in the early summer and again in the fall
Correct: This case describes the appearance of the horse bot fly, Gasterophilus spp. Gasterophilus is frequently asymptomatic but treatment is recommended because bots can cause gastritis and frequently are a source of annoyance and stress to horses. In addition, the larval instars can cause stomatitis, and colic.
The key to answering this question regarding optimal treatment and management is an understanding of the Gasterophilus life cycle. Gasterophilus undergoes complete metamorphosis, including three larval instars and only one generation is produced per year. The general cycle typically begins with the female ovipositing 150-1,000 eggs on a horse during the early summer months directly on single hairs of the horse's front legs (especially around the cannon bone area) as well as the abdomen, flanks, and shoulders. The eggs are approximately 1-2mm long and are pale to grayish yellow attached near the tip of the hair.
The eggs develop into first instar larvae within five days and they are stimulated to emerge by the horse licking or biting at the fully developed eggs. The larvae then crawl to the mouth or are ingested and subsequently bury themselves in the tongue or gingiva and remain for approximately 28 days. The larvae molt to the second stage and move into the stomach. The second and later third stage larvae typically attach to the lining of the stomach in the non-glandular portion near the junction of the esophageal and cardiac regions where they remain immobile for the following 9 to 12 months.
The third instar larvae are relatively large, between 1-2cm long with a rounded body, narrow, hooked mouthparts, and spines. The hooked mouthparts enable the larvae to securely attach to the lining of the stomach and intestinal tract. After the third instar larvae have matured, they detach from the gastrointestinal tract and pass from the horse's body in the feces. The larvae burrow into the soil or dried manure where they pupate and remain for the next one to two months. This stage of the life cycle occurs between late winter and early spring.
Based on this life cycle, the recommended management protocol is typically to treat with an avermectin to control adults and all larval stages by administering in the early summer, shortly after any eggs are seen and again in the fall at the end of the botfly season. Such a control program will substantially reduce fly numbers.
D. Inability to close the mouth
Correct: Idiopathic trigeminal neuritis, cranial nerve 5, (CN 5) is characterized by acute onset of flaccid jaw paralysis.
Affected animals cannot close their mouth and have difficulty eating and drinking.
Seen occasionally in dogs, rare in cats. Cause is unknown.
Idiopathic facial nerve paralysis, cranial nerve 7, (CN 7) results in the inability to move the eyelid, lip, or ear and dryness of the eyes and mouth.
Masticatory myositis is characterized by pain on opening the mouth and swelling of the muscles of mastication (acute) or atrophy of the temporalis and masseter muscles with the inability to open the mouth due to fibrosis (chronic).
Dysphagia, dyphonia, and stridor are most often associated with dysfunction of the vagus nerve, cranial nerve 10 (CN 10).
Circling and head tilt toward the side of the lesion with no other signs is a common presentation of vestibulocochlear nerve, cranial nerve 8 (CN 8) lesions.
Concurrent CN 7 paralysis and Horner's syndrome (ptosis, miosis, enophthalmis) may be present with middle- and inner-ear infections.
C. Treat the other calves with vitamin E/Selenium
Treat the other calves with vitamin E/Selenium.
Think of white muscle disease when you see SUDDEN DEATH and endocardial PLAQUES in a young calf, lamb or kid with a history of recent VIGOROUS EXERCISE.
Image of pale ventricular myocardium.
Typically seen in young, fast-growing animals (ie: calves 2 weeks-6 mos).
Clinical signs may include dyspnea (due to myocardial disease), stiff gait, arched back, weakness, recumbent but BAR (bright, alert, responsive).
Sudden death may resemble enterotoxemia, should see acute bloody diarrhea, convulsions, opisthotonos in first days of life with enterotoxemia.
C. Diabetes mellitus, Cardiomyopathy, Renal disease
Correct: Think first of Diabetes mellitus in OLDER MALE cats (ave. 10 yr, 90% male) with Feline acromegaly.
First presenting sign may be PU/PD, polyphagia of diabetes. WEIGHT GAIN in an unregulated diabetic cat STRONGLY SUGGESTS acromegaly.
Think also of Cardiomyopathy (~50%; see weakness, dyspnea, systolic murmur, cardiomegaly/CHF, pulmonary edema ).
Think also of RENAL disease (~50%; see proteinuria, USpG 1.015-1.025, (and glucosuria from Dm)).
May see prognathism (long mandible), lameness (esp. cats), marked vertebral spondylosis.
Acromegaly is associated with what 3 diseases in cats?
A. Hypoadrenocorticism, Congestive heart failure, Hepatic lipidosis
B. Hyperadrenocorticism, Pleural effusion, Renal disease
C. Diabetes mellitus, Cardiomyopathy, Renal disease
D. Prognathism, Pulmonary edema, Pulmonary Hypertension
E. Vertebral spondylosis, 3rd degree heart block, Glomerulonephritis
Which one of the following sets of conditions predispose a cow to metritis?
A. Dystocia, overfeeding in dry period, Ca-P imbalance in feed
B. Agalactia, milk fever, bovine vibriosis
C. Strep. agalactiae mastitis, retained placenta, laminitis
D. Milk fever, malnutrition, excess dietary zinc
E. Contaminated calving environment, abortion, hypomagnesemia
A. Cavalier King Charles spaniel, Cocker spaniel
Correct: Think of mitral regurgitation/insufficiency in a Cavalier King Charles Spaniel of any age, or in old male Cockers with a Hx of cough, labored breathing, and exercise intolerance.
Remember that chronic obstructive pulmonary disease with fibrosis can cause similar signs-primarily older animals.
Here are 4 other big cardio predispositions:
If you see an intermittently fainting Boxer, think of Boxer cardiomyopathy.
A rapid, irregular heart rate in a middle-aged, depressed, coughing, exercise-intolerant Doberman, suggests dilated cardiomyopathy (DCM).
Think of Sick Sinus Syndrome (SSS) when you hear "Fainting Female Min. Schnauzer".
Also see SSS in dachshunds, cockers, west highland whites.
Think Tetralogy of Fallot in a young Bulldog, Keeshond, Wirehaired Fox Terrier with cyanosis, exercise intolerance.
Remember young Min. Schnauzers and Wirehaired Fox Terriers are predisposed to Mega-esophagus.
D. Feminization syndrome.
Correct: Nonpainful unilateral testicular swelling in an old dog should make you think of neoplasia, especially an estrogen-secreting sertoli cell tumor, which can cause feminization syndrome.
See gynecomastia, penile atrophy, pendulous prepuce, attraction of other males, blood dyscrasias, +/-bone marrow depression (via high estrogen), bilateral alopecia.
Remember that cryptorchidism increases risk of sertoli cell tumor:
About 25-29% of sertolis develop feminization syndrome and ~ 70% of intra-abdominal testicular tumors, regardless of type, cause feminization syndrome.
May see prostate hypertrophy with sertoli, but it is due to squamous metaplasia, not the classic (and common) benign prostatic hypertrophy (BPH).
Hypothyroidism and BPH are common older dog conditions, but not associated with unilateral testicular hypertrophy.
Remember that sex hormones are also secreted by the zona reticularis of adrenal cortex and can see feminization or virilism with excess secretion.
Correct: Encephalomyocarditis virus (EMCV) is caused by a cardiovirus in the family picornaviridae. Confusingly, the virus is named for its effects on mice.
Think of rodents and exotic zoo mammals with EMCV.
Pig-to-pig contact, contamination of swine feed and water by rodents or ingestion of dead rodents may cause disease. See pulmonary edema and copious transudate in the respiratory tract, causing cardiac failure.
Zoo outbreaks of EMCV have included lions, African elephants, rhinos, hippos, sloths, llamas, antelope and nonhuman primates. An outbreak of lion deaths at a Florida zoo in the USA occurred after feeding them the carcass of an African elephant that had died of EMCV.
Edema disease is a neurologic disease caused by a hemolytic Escherichia coli producing Shiga toxin e2 and F18 pili resulting in high mortality in recently-weaned pigs.
Glasser's Disease, caused by Hemophilus parasuis is usually an acute disease of 6 to 8 week-old pigs which causes fibrinous arthritis, polyserositis, and meningitis.
Porcine Reproductive and Respiratory Syndrome (PRRS), is an arterivirus causing reproductive failure and post-weaning respiratory disease.
Pseudorabies is a herpesvirus: infection causes CNS disease in neonates, respiratory disease in weaned pigs, and fever in all ages.
B - Common opening of the pancreatic and common bile ducts into the duodenum.
Correct: It is thought that this may predispose them to ascending cholangitis and pancreatitis after vomiting associated with inflammatory bowel disease, resulting in extrahepatic biliary obstruction.
Other possible etiologies of EHBO include neoplasia, biliary stricture, duodenal obstruction, diaphragmatic hernia, and parasitic infection.
In all cases, there is a lack of bile entry into the intestinal tract, leading to decreased absorption of fat and fat soluble vitamins such as vitamin K, potentially resulting in coagulopathies.
Except in transient cases that are related to acute pancreatitis, surgical intervention to relieve the obstruction is required as well as appropriate supportive care, antimicrobial treatment, and vitamin K administration.
Click here to see a good summary on extra-hepatic biliary obstruction with images, courtesy of the American College of Veterinary Surgeons (ACVS).
Correct: The cells depicted are well-differentiated adipocytes. These cells are large, appear in aggregates or sometimes singly, and contain fat that stains negatively with Wright's, such that the cytoplasm appears clear. The cells possess a small, round or ovoid, pyknotic nucleus that may be compressed and located in the periphery of the cell. This benign tumor is a lipoma, which is common in dogs. If the mass hinders the animal, it may be removed surgically. Infiltrative lipomas, and their malignant counterpart, liposarcomas, are less common.
When sampling for cytology, frequently the first indication that a lipoma has been aspirated is the clear, oily appearance of the material ejected from the aspiration needle onto the slide. Care must be taken while staining to ensure that the material does not wash off the slide, as fat does not adhere readily to the glass surface.
Note: Gentle heat fixing of greasy material to a slide may be of benefit in keeping adipose cells adherent to slides during staining. This can be accomplished by holding a slide over a Bunsen burner or lighter or gentle heating on a heating tray/bar for a few seconds so that the side opposite to that containing the cellular material is slowly warmed. The slide must be left to cool completely before staining. Slides coated with poly-l-lysine, which are used for Papanicolaou staining and/or increased adherence of tissue sections to slides, are also helpful in promoting cellular adherence and eliminating loss of cells during staining.
Sometimes, local fat will be aspirated and cannot be reliably differentiated from the adipose cells of a lipoma. If there is any doubt as to the presence of a discrete mass, surgical removal with histological evaluation is recommended.
B - 89%.
Correct: Remember - you are comparing TWO TESTS here. PVP means "Of the turtles my test says are positive (27), how many are truly positive?" (27-3=24, this # goes in the "a" box)
Here is how you do it: First, draw a 2x2 table, and label the boxes a,b,c,d. PVP = a/(a+b). Now, add in the TOTAL number of animals (100), the total positive by YOUR test (27) and the total negative by YOUR test (73).
Now the (slightly) tricky part. Add in the numbers that YOUR test got WRONG according to the gold standard test. (3 false pos in box b, 10 false neg in box c):
Last, subtract to fill in your "d" box (73-10=63) and do the math to calculate PVP = a/(a+b)=24/27=0.89 or 89%.
FYI: You can calculate sensitivity a/(a+c), specificity d/(b+d), Predictive Value POS (PVP) a/(a+b) and Predictive Value NEG (PVN) d/(c+d) with the same 2x2 table.
Correct: Cuterebra is a fly that lays its eggs on soil or plants. The eggs stick to the animal's fur when they come into contact. The eggs hatch, and the larvae either penetrate the skin, are ingested when the animal grooms, or they enter the animal's body through a natural opening, such as the nose.
In most cases, the larvae migrate to areas just under the skin on the head, neck, or trunk of the animal. In dogs, cats, and ferrets, who are not the usual hosts of this parasite, the larvae may also migrate to the brain, eye, eyelids, or throat.
As the larva grows under the skin, it produces a nodule or swelling. A small opening develops in the skin, through which it breathes. A small amount of drainage may occur around this breathing hole.
The treatment is to incise the skin if needed to remove the larva. You have to make sure to remove the larva in whole and not crush it. If it is damaged or crushed, it can cause an anaphylactic reaction.
Ctenocephalides is a flea, Ancylostoma is the hookworm, and Culicoides are tiny gnats that most often bother horses and livestock.
Which diseases are classically associated with a high anion gap (AG)?
A - Eosinophilic enteritis, Hypothyroidism, Gastrinoma
B - Prostatic adenocarcinoma, Pleural effusion, Lymphangiectasia
C - Diabetes mellitus, Pancreatitis, Proliferative enteritis
D - Hypercalcemia of malignancy, Hypoadrenocorticism, Displaced abomasum
E - Grain overload, Ethylene glycol toxicity, Renal insufficiency
C - Vitamin A deficiency
Correct: This is the clinical picture of vitamin A deficiency, a problem primarily seen in TURTLES, but also in alligators and other reptiles.
Look for swollen eyes, discharge from nose/mouth/eyes and ear infections. Vitamin A deficiency can predispose to a bacterial pneumonia.
Like other key reptile issues (metabolic bone disease for example), the problem is basically nutritional and preventable.
Inclusion body disease is a viral problem of boa constrictors and some pythons.
Septicemic cutaneous ulcerative disease (SCUD) is a shell disease (Citrobacter freundii). Look for pitted shells.
Herpesvirus causes oral mucosa necrosis, anorexia, regurgitation, oral, ocular discharge, but discharge from the nose and swollen eyes should put vitamin A deficiency, not herpes, at the top of your DDX.
West nile virus (WNV) has been diagnosed in farmed alligators with multiorgan necrosis, heterophilic granulomas, heterophilic perivasculitis, and lymphoplasmacytic mengingoencephalitis.
Very high WNV viremia titers have been reported in different reptiles, suggesting that they may play a role as amplification hosts for the virus.
ZOONOTIC NOTE: Remember SALMONELLA when you think of children with pet turtles or other pet reptiles.
A - T13, L1, and L2
Correct: The spinal nerves, T13, L1, and L2 must be blocked to completely desensitize the flank of a cow. The paravertebral (PV) nerve block targets these nerves. It can be performed via two techniques - the proximal or distal PV block.
The proximal block places local anesthetic in the space just caudal to the transverse processes of the vertebrae - T13, L1, and L2.
The distal block is placed at the ends of the transverse processes of the vertebrae - L1, L2, and L4 as the nerves gradually course caudally after they exit the spinal foramen.
Proper placement of the anesthetic results in warming of the skin from vasodilation, anesthesia of the skin and body wall, and a curvature of the spine in some cows.
The latter is caused by relaxation of the epaxial musculature on the affected side; the spine curves in a convex manner.
Which of the following nerves are targeted with a paravertebral block used to perform a standing laparotomy in a cow?
A - T13, L1, and L2
B - L1-3, and S1-5
C - L2, L3, S1, and S2
D - L1, L2, L3
E - L1, L2, and L4
Correct: This is infectious bovine rhinotracheitis (IBR) with pustular vulvovaginitis, caused by bovine herpesvirus 1.
IBR is a common infection in cattle. Infected animals develop fibrinonecrotic plaques at the site of inoculation, and from there, the virus ascends to the regional ganglia where the virus becomes latent.
During stressful episodes, recrudescence of latent virus occurs , and virus particles are shed, perpetuating infection in herds.
There are several different types IBR virus with different tissue specificites. One type causes mucosal lesions and respiratory or vaginal infections. A second type primarily causes abortion, and a third causes fatal nonsuppurative encephalitis in calves.
IBR is identifiable by the fibrinonecrotic plaques on the mucosal eithelium, and may be confirmed by collection of nasal or ocular swabs for virus isolation, ELISA, or fluorescent antibody testing.
All cattle should be vaccinated against IBR virus with a modified live vaccine (MLV) at 6 months of age, or earlier if the disease exists on a specific farm.
The MLV vaccine prevents abortion, and reduces clinical signs, but most live vaccines will cross the placenta and kill the fetus, so they are not recommended for use in pregnant cattle.
B - Infectious laryngotracheitis
Correct: Blood in the trachea and this Hx suggest infectious laryngotracheitis (ILT). A highly contagious herpesvirus infection, ILT is characterized by RESPIRATORY signs (rales, severe dyspnea, coughing). In severe forms, mortality can reach 50%, typically due to occlusion of the trachea by blood, mucus or caseous exudates. In most states ILT is REPORTABLE.
Infectious coryza is a milder respiratory disease, with swelling around the eyes and head, sneezing, nasal discharge.
Newcastle disease is characterized primarily by respiratory signs. Severe forms include depression, neurologic signs or diarrhea. Look for GI hemorrhage with most severe form, Viscerotropic Velogenic Newcastle disease (VVND), which is REPORTABLE.
With fowlpox, only a few birds typically affected with scablike lesions around head.
See only depression before death with Marek's disease . Some birds may have characteristic unilateral paresis (one leg forward, one leg back). On necropsy, see lymphoid tumors in organs and enlarged nerves
B - Trichomonosis, microscopic smear
Correct: This is trichomonosis , caused by Trichomonas gallinae, and diagnosed by microscopic smear exam of the caseous oral exudates. Look for trichomonads. More a problem in PIGEONS, but can cause disease in chickens.
Try not to confuse avian Trichomonas with Tritrichomonas foetus of cattle, which causes infertility (early embryonic death actually, 1st 2 months pregnancy). Infected bulls are mechanical carriers to cows.
Candidiasis is a fungal disease that can look SIMILAR to trichomonas in chickens.
- Caused by Pasteurella multocida, fowl cholera causes sudden onset septicemia with VARIABLE signs. (Sudden death, anorexia, depression, mucoid beak discharge, ruffled feathers, diarrhea, increased RR.
- Aspergillosis presents as respiratory disease. See fungi on microscopic smear, may see granulomatous lumps in lungs.
- See sudden death with necrotic enteritis, caused by Clostridium perfringens.
Correct: The negative predictive value is the proportion of test-negative animals that are truly disease negative (unaffected) in this population. In the 2X2 table, where a= Disease +, Test +; b= Disease -, Test +; c= Disease +, Test -; d= Disease -, Test -. The NPV is d/(c+d), or disease -, test - animals DIVIDED by all of the test - animals.
The answer to the question has to consider the prevalence of mastitis in the herd, which here is 5%. As the prevalence declines, NPV will increase.
The negative predictive value gives a proportion of the negative tests that are truly negative. The value is the number of true negatives divided by the sum of the true negatives and false negatives.
In this herd, the proportion of test negative animals that actually is negative is specificity x (1-prevalence) or (0.9)x(0.95) = 0.855 (d). The proportion of false negatives in the herd is (1-sensitivity) x prevalence, or (0.1)(0.05) = 0.005 (c).
Negative predictive value = d/(c+d) = 0.855/(0.855+0.005) = 0.994.
D - Pyelonephritis
Correct: This is the clinical picture of a cow with early signs of pyelonephritis. Onset is typically insidious. The first clinical sign may be passage of blood-stained urine (hematuria) in an otherwise normal animal.
As infection (usually Corynebacterium spp.or E. coli) ascends up the ureters into the kidney, the cow may display frequent attempts to urinate, anorexia, a slight fever, loss of production, colic, restlessness, tail switching, polyuria, more hematuria or pyuria.
Early in the disease, enlarged ureters and involvement of the kidney may not be detectable on rectal palpation. In chronic cases, the left kidney may be enlarged, with loss of lobulation and pain. The cow may show colic, diarrhea, polyuria, polydipsia, stranguria, and anemia.
C. Butorphanol and theophylline
Correct: The radiographs show dynamic collapse of the intrathoracic trachea, carina, and mainstem bronchi. There is a marked redundant tracheal membrane in the cervical region. The left atrium may be slightly enlarged but there is no evidence of left heart failure. Based on these findings, you should suspect that tracheal collapse is the cause of the dog's clinical signs.
Treatment options include bronchodilators (i.e. theophylline, terbutaline), cough suppressants (hydrocodone, butorphanol), weight loss, and corticosteroids to control inflammation. In severely affected dogs, sedation may be necessary to break the cough cycle. Dogs should be kept away from smoke and environmental pollution. About 70% of dogs respond to medical management. Those that don't are sometimes treated with stents or tracheal rings, but neither repairs the underlying cartilaginous defect.
Furosemide is not an appropriate treatment as there is no evidence of heart failure. Nebulization and coupage are used to treat pneumonia, which is also not present in this case.
You examine a very ill 4-year old Holstein dairy cow on a large commercial dairy. She freshened one week ago and was producing well, until she was found down and unwilling to rise this morning when you were called. T=103F or 39.4 C, HR=90, and RR=35. The scleral vessels are dark are enlarged, her rumen is fairly empty and the motility is poor, and she appears too weak to rise. Rectal exam reveals an involuting uterus which can be retracted, discharging a brownish red mucoid non-odorous lochia through the vagina. The left rear quarter of her udder is swollen, hot, painful, and discolored (see image), and contains a serum-like secretion with clumps of fibrin in it. What is your diagnosis?
B. Displaced abomasum
C. Hypocalcemia (milk fever)
D. Grain overload
E. Coliform mastitis
C - Infectious Coryza.
Correct: Think acute respiratory disease with nasal discharge, sneezing, and SWELLING UNDER THE EYES.
Caused by Avibacterium (Haemophilus) paragallinarum, infected flocks are a constant threat to uninfected flocks; farms with multiple-age flocks can perpetuate disease.
In the USA, "All-in/all-out" management has essentially eliminated infectious coryza from many commercial poultry farms.
Infectious laryngotracheitis (ILT) look for gasping, coughing, blood stained beaks, blood occluding trachea on necropsy.
A highly contagious herpesvirus infection, severe forms of ILT, can have 50% mortality.
In most states ILT is REPORTABLE.
Infectious bronchitis is characterized by respiratory signs, decreased egg production and poor egg quality.
Classically, you may see "wrinkled eggs" with infectious bronchitis.
Pasteurella multocida causes fowl cholera. Think sudden onset septicemia. Signs vary greatly.
In acute fowl cholera, dead birds are first indication of disease.
May see fever, depression, anorexia, oral mucoid discharge, ruffled feathers, diarrhea, increased respiratory rate.
Another name for Candidiasis is thrush.
Think Candida albicans, thickened mucosa, whitish, raised pseudomembranes in crop, mouth and esophagus.
A - Equine ehrlichiosis.
This is one of the 5 classic "anemia / edema " presentations of horses.
Remember "Big 3 are PEE" Purpura, EIA, EVA; 2 minors are Babesia, ehrlichia (now renamed Anaplasma).
Inclusion bodies in the neutrophils of a California horse with icterus and petechiae and an undulating fever says Equine granulocytic ehrlichiosis (EGE).
Originally classified as Ehrlichia equi, but is NOW called ANAPLASMA phagocytophilum due to DNA sequencing studies.
EGE is a seasonal necrotizing vasculitis (edema, icterus, petechiae) seen in N. California, suspected to be tick borne.
See dependent edema with Equine viral arteritis (EVA), but also should see respiratory presentation (conjunctivitis/pinkeye, rhinitis) +/- abortions.
Equine infectious anemia (EIA) is rarely seen today because of testing programs, but could present this way.
Less likely because 92% cases seen around the Gulf of Mexico states (Texas to Florida), Mississippi river valley AND no inclusion bodies.
Purpura hemorrhagica is a type III Antigen/Antibody/Complement complex disease causing vascultis, petechia, purplish discoloration, usually afebrile, with Hx of recent Strangles (Strep equi equi) or bacterin vaccination.
Equine Babesiosis presents more as a hemolytic anemia: seen in the S. USA, endemic in Southern FLORIDA.
A - Use high-dose antibiotics for sick piglets.
Correct: This is exudative dermatitis ("greasy pig disease"), caused by Staph hyicus.
Responds to most antibiotics (pen, amoxi, TMS, erythromycin, lincomycin, tylosin, AGs, cephs) at high dose 7-10 days, plus topical antiseptic.
In severe outbreaks, antibiotics for contact pigs recommended for a few days. Disinfection, good environmental hygiene important.
In chronically affected herds, autogenous bacterins have been used with some success to decrease incidence.
E. Fecal float
Correct: Hookworms (Ancylostoma and Uncinaria) are intestinal parasites that suck blood and can cause anemia, enteritis, coughing during larval migration, and dermatitis. Any young dog that is failing to thrive and/or has pale mucous membranes should be tested for intestinal parasites. Hookworm dermatitis, also called Ancylostomiasis is typically seen in conditions with poor sanitation and/or in kennels.
Hookworms can be transmitted in utero, during nursing, or via 3rd stage larva penetrating the skin. The most commonly affected skin areas are the pads and interdigital spaces of the feet, but can include any surface that contacts the ground. The larva migrate through the dog's tissues before arriving in the intestines. They cause significant anemia, failure to thrive, or sudden death in young dogs. In mild cases, deworming protocols are often enough; with severe cases blood transfusions and parenteral treatments are often necessary.
Skin scraping and impression smears of the affected skin areas are typically unrewarding for isolating parasites. A PCV/TP would show signs of anemia, but not the underlying etiology. Complete blood cell count and chemistry will often show anemia that is regenerative and an eosinophilia. Radiographs would be unrewarding in this case. A biopsy may show migrating larva if biopsied soon after trauma, however this is not a diagnostic test routinely used.
C - Proximal enteritis
Correct: Proximal enteritis, or duodenitis-proximal jejunitis, is a clinical syndrome characterized by large volumes of gastric reflux resulting from excessive fluid and electrolyte secretion into the small intestine and small intestinal inflammation and edema.
Laminitis is an important potential sequela.
The cause is unknown but several bacteria and toxins including Clostridium difficile, Clostridium perfringens, Salmonella, and fumonosin B1 mycotoxins have been implicated.
Ulcerative duodenitis is a disorder of foals resulting in fever, colic, diarrhea, and delayed gastric emptying.
Lawsonia intracellularis causes proliferative enteropathy in foals and weanlings, a disease characterized by hypoproteinemia, diarrhea, chronic ill thrift, and ventral edema.
Right dorsal colitis is typically a result of non-steroidal anti-inflammatory drug toxicity and results in hypoproteinemia and colic.
Cantharidin toxicity (blister beetles, Epicauta spp.) causes a wide range of clinical signs predominated by profuse diarrhea, stranguria and pollakiuria, and colic.
A. The thin, white, glistening amniotic membrane emerges from the vulva
Correct: This case description is consistent with stage I of labor in the horse. The first stage of foaling typically lasts 30 minutes to 4 hours. During this stage, mares act restless and may exhibit signs similar to colic such as flank watching, pawing, and constantly getting up and down. When the placenta ruptures ("water breaks"), there may be several gallons of allantoic fluid that come out. Usually, within about 5 minutes, the second stage of labor begins and the foals feet and nose appear at the vulva, covered in the white, thin, glistening amnion. If a red, velvety, membrane is seen, this is the chorioallantois which indicates premature placental separation which can impair oxygen delivery to the fetus and can result in death of the foal. Usually, the muzzle will emerge from the amnion by the time the foal's hips pass through the pelvis but if not, the amnion can be gently broken and removed. Usually, the umbilical cord breaks naturally when the mare stands or foal begins to rise. Then, within 30 minutes to 3 hours after foaling, the placenta should be expelled.
Correct: Based on the description of the cytology and clinical symptoms of this cat, the most likely diagnosis is Cryptococcus neoformans. This is a fungal disease that occurs when the organism is inhaled and is disseminated to skin, eyes, CNS, lungs, or other areas. The upper respiratory tract is most often involved and symptoms can include nasal discharge, sneezing, swelling over the nose, and regional lymphadenopathy. If the CNS is involved, seizures can also occur. The disease has been thought to be transmitted most often through infected pigeon droppings. Itraconazole or fluconazole are the anti-fungals of choice for this disease. Doxycycline, Trimethoprim sulfa, and Clavamox are all antibiotics and would not address a fungal infection. Lufenuron is a flea treatment that has had some implications for treatment of dermatophytes due to its ability to inhibit chitin. About 1/3 of the cell wall of a fungus is composed of chitin. This has not been a promising or approved treatment for ringworm and surely would not be an appropriate treatment for Cryptococcus.
B - Premature ventricular contractions.
Correct: Three premature ventricular contractions (PVCs) are present on this ECG strip.
Usual characteristics of PVCs - No p wave present that is associated with the QRS wave, the QRS is wider than normal and bizarre in shape compared to normal, often the QRS is oriented opposite to that of the sinus beats.
The orientation of the QRS is the same (both negative) in both the normal and ectopic beats in this case.
Don't be fooled by the presence of the small waveform just before the PVC, these are the T waves from the prior beat.
Cardiac arrhythmias that occur under anesthesia can be caused by hypercarbia, hypoxemia, hypotension, hypothermia, anesthetic drugs, sympathetic stimulation, electrolyte disturbances, and myocardial disease.
This foal had just been induced with isoflurane, was likely hypoventilating, and a little deeper than necessary.
The isoflurane was decreased, she was put on a ventilator - the PVCs disappeared and did not return.
C - Trigeminal neuritis
Correct: Idiopathic trigeminal neuritis, cranial nerve 5, (CN 5) is characterized by acute onset of flaccid jaw paralysis.
Affected animals cannot close their mouth and have difficulty eating and drinking.
In some cases unilateral or bilateral Horner's syndrome, facial paresis, and decreased facial sensation are present.
Most common in dogs, rare in cats. Cause is unknown.
Idiopathic facial nerve paralysis, cranial nerve 7 (CN 7) results in the inability to move the eyelid, lip or ear and dryness of the eyes and mouth.
Masticatory myositis, an immune-mediated disease of dogs, is characterized by pain on opening the mouth and swelling of the muscles of mastication (acute) or atrophy of the temporalis and masseter muscles with the inability to open the mouth due to fibrosis (chronic).
Myasthenia Gravis (MG), a neuromuscular disease, typically presents with episodic or exercise-induced weakness due to impaired transmission of acetylcholine at the neuromuscular junction of skeletal muscles.
Meningoencephalitis, inflammation of the brain and meninges, should always be on the differential list. Lesions may be anywhere in the CNS and may present with any neurological signs.
C - Liver and muscle
Correct: Damage to liver and muscle cells of dogs and cats causes increased serum levels of alanine aminotransferase (ALT).
ALT is a considered a "leakage" enzyme. High levels are normally found in the cytoplasm of healthy cells.
When hepatic or muscle cells are damaged, ALT leaks into adjacent tissue where it is picked up by the venous circulation.
Other animals such as horses, ruminants, pigs, and birds do not have high levels of ALT inside cells.
Aspartate aminotransferase (AST) is the leakage enzyme predominant in these animals.
The magnitude of the elevation of leakage enzymes can be deceiving - are a few cells leaking a lot or many cells are leaking a small amount?
Severe damage to a healthy liver may result in very high levels, while low levels may be seen when significant atrophy or fibrosis of the liver is present and few cells are left.
Prognosis of the former may be good, for the latter it is certainly grim.
Differentiation between muscle and liver as the source of increases in ALT/AST is determined by evaluation of other muscle (creatine phosphokinase (CK) and AST) and liver enzymes (AST, sorbitol dehydrogenase (SDH), gamma glutamyl transferase (GGT), alkaline phosphatase (ALP)), the animal, and the clinical evaluation.
Leakage enzymes do NOT provide an estimate of actual liver function. This is evaluated by measurement of substances dependent on the efficacy of liver function such as bile acids, blood urea nitrogen, albumin, and glucose.