NAVLE practice questions

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Question 1Canine and feline (companion animal) practice

A 4-month-old unvaccinated puppy is presented with acute vomiting, bloody diarrhea, lethargy, and fever. The CBC shows leukopenia. What is the most likely diagnosis?

Giardia duodenalis infection
Hemorrhagic gastroenteritis
Canine parvovirus enteritis Correct answer.
Canine coronavirus enteritis

Explanation

Canine parvovirus causes severe necrotizing enteritis in young unvaccinated dogs, often with vomiting, hemorrhagic diarrhea, fever, and marked leukopenia. Diagnosis is supported by fecal antigen testing or PCR. The other conditions can cause diarrhea but do not typically produce this combination of severe hemorrhagic enteritis and leukopenia.

Question 2Canine and feline (companion animal) practice

A 12-year-old cat has weight loss despite a good appetite, tachycardia, and a palpable cervical mass. Which test is the best initial screening test for hyperthyroidism?

Serum thyroid-stimulating hormone
Thyroid scintigraphy
Fine-needle aspirate of the gland
Serum total thyroxine Correct answer.

Explanation

Hyperthyroidism is confirmed by an elevated serum total thyroxine (T4) concentration in a cat with compatible clinical signs. TSH is typically low and is not used as the initial screening test. Scintigraphy and cytology are advanced or supportive tests, not first-line screening.

Question 3Canine and feline (companion animal) practice

A 3-year-old dog lives in a heartworm-endemic area and has never received prevention. Before starting monthly preventive, which test is most appropriate?

PCR on blood for microfilariae
Serum antibody test for Dirofilaria immitis
Echocardiography for adult worms
Antigen test for Dirofilaria immitis Correct answer.

Explanation

Dogs should be tested for adult heartworm infection before starting a preventive, and the antigen test detects adult female Dirofilaria immitis. Antibody testing does not distinguish active infection well, and echocardiography and PCR are not routine screening tests.

Question 4Canine and feline (companion animal) practice

A male cat is straining to urinate, vocalizing, and has a tense urinary bladder. He is obtunded and has hyperkalemia. What is the most immediate priority?

Perform perineal urethrostomy
Relieve the urethral obstruction Correct answer.
Administer furosemide to increase urine flow
Start oral antibiotics for cystitis

Explanation

Urethral obstruction is a life-threatening emergency because retention causes hyperkalemia, acidosis, and cardiac arrhythmias. The immediate priority is to relieve the obstruction and correct fluid and electrolyte abnormalities. Antibiotics and surgery are not immediate first steps in an unstable obstructed cat.

Question 5Canine and feline (companion animal) practice

Which vaccine is considered core for all dogs regardless of lifestyle?

Borrelia burgdorferi vaccine
Rattlesnake toxoid
Bordetella bronchiseptica vaccine
Rabies virus vaccine Correct answer.

Explanation

Core vaccines for dogs are those recommended for all dogs because of widespread risk or public health importance: rabies, canine distemper, canine parvovirus, and canine adenovirus. Bordetella, Borrelia, and rattlesnake vaccines are selected based on lifestyle or geographic risk.

Question 6Canine and feline (companion animal) practice

A young unvaccinated kitten has fever, vomiting, diarrhea, and profound neutropenia. Which virus is most likely responsible?

Feline parvovirus Correct answer.
Feline calicivirus
Feline herpesvirus-1
Feline coronavirus

Explanation

Feline parvovirus causes panleukopenia, with fever, vomiting, diarrhea, and marked neutropenia in susceptible kittens. Herpesvirus and calicivirus primarily cause upper respiratory signs, and feline coronavirus usually causes mild enteritis or FIP.

Question 7Canine and feline (companion animal) practice

A dog with chronic otitis externa has a dark, waxy discharge. Cytology shows many Malassezia yeasts. Which treatment is most appropriate?

Oral griseofulvin
Topical glucocorticoid alone
Topical miconazole Correct answer.
Systemic enrofloxacin

Explanation

Malassezia otitis is treated with topical antifungal agents such as miconazole or clotrimazole, often after gentle ear cleaning. Glucocorticoids reduce inflammation but do not eliminate yeast, and griseofulvin is used for dermatophyte infections rather than Malassezia.

Question 8Canine and feline (companion animal) practice

Which dental condition is most common in adult dogs and results from plaque accumulation?

Enamel hypoplasia
Periodontal disease Correct answer.
Oropharyngeal neoplasia
Tooth fracture

Explanation

Periodontal disease is the most common dental disease of adult dogs; plaque accumulation leads to gingivitis and progressive loss of periodontal support. Enamel hypoplasia, neoplasia, and fractures are important but are not caused primarily by plaque.

Question 9Canine and feline (companion animal) practice

A 9-year-old obese female dog has polyuria, polydipsia, and weight loss. Blood glucose is 420 mg/dL, and urine glucose is present without ketones. What is the most appropriate initial insulin therapy?

NPH insulin twice daily Correct answer.
Once-daily ultralong-acting insulin without monitoring
Rapid-acting insulin as needed
Oral glipizide alone

Explanation

Most diabetic dogs are managed with an intermediate-acting insulin such as NPH or porcine lente given twice daily, along with diet and glucose monitoring. Rapid-acting insulin alone is not suitable for maintenance, and oral sulfonylureas are generally ineffective in dogs.

Question 10Canine and feline (companion animal) practice

A 5-year-old cat has recurrent cough and wheeze; thoracic radiographs show bronchial thickening, and bronchoalveolar lavage shows eosinophilia. Which treatment is most appropriate for long-term control?

Inhaled corticosteroid Correct answer.
Long-term doxycycline therapy
Oral phenylephrine
Oral enalapril

Explanation

Feline asthma is an allergic inflammatory airway disease, and inhaled corticosteroids are the mainstay of long-term control. Bronchodilators may be used for rescue, while antibiotics and cardiac drugs do not treat the underlying inflammation.

Question 11Canine and feline (companion animal) practice

A young female dog has waxing and waning vomiting, weakness, and collapse. Serum sodium is 128 mEq/L, potassium is 6.8 mEq/L, and the Na:K ratio is 19. What is the most likely diagnosis?

Hypothyroidism
Hypoadrenocorticism Correct answer.
Primary hyperaldosteronism
Diabetes insipidus

Explanation

Hypoadrenocorticism (Addison disease) commonly causes hyponatremia, hyperkalemia, and a Na:K ratio below 27, along with vague gastrointestinal and weakness signs. Confirmatory testing is an ACTH stimulation test. Hyperaldosteronism tends to cause hypertension and hypokalemia, not hyperkalemia.

Question 12Canine and feline (companion animal) practice

A dog has pale mucous membranes, icterus, PCV 16%, spherocytes, and autoagglutination. What is the most likely diagnosis?

Immune-mediated hemolysis Correct answer.
Mycoplasma haemocanis infection
Iron-deficiency anemia
Aplastic anemia

Explanation

Spherocytes and autoagglutination are classic features of immune-mediated hemolytic anemia, which often causes pale mucous membranes and icterus. Glucocorticoids are the initial treatment. Mycoplasma can cause hemolysis, but the spherocyte and autoagglutination pattern strongly supports immune-mediated disease.

Question 13Canine and feline (companion animal) practice

A dog is in continuous seizure activity for 5 minutes. What is the first-line medication?

Oral potassium bromide
Intravenous diazepam Correct answer.
Oral phenobarbital
Intravenous hypertonic saline

Explanation

Status epilepticus is first treated with a benzodiazepine such as intravenous diazepam or midazolam to stop ongoing seizure activity. Phenobarbital and potassium bromide are maintenance anticonvulsants, and hypertonic saline is used for specific osmotic or neurologic problems, not as an anticonvulsant.

Question 14Canine and feline (companion animal) practice

A 14-year-old cat has weight loss, polyuria and polydipsia, creatinine 2.8 mg/dL, and urine specific gravity 1.012. Which is most appropriate initial management?

Oral potassium binder
Restrict water intake
Renal diet, free water Correct answer.
High-dose furosemide therapy

Explanation

This cat has chronic kidney disease with impaired concentrating ability, so water should not be restricted. Initial management includes a renal diet and free access to water, with monitoring of hydration, electrolytes, and blood pressure. Furosemide can worsen dehydration, and potassium binders are used for hyperkalemia when present.

Question 15Canine and feline (companion animal) practice

A dog has acute vomiting, cranial abdominal pain, and lethargy. Which test is most specific for pancreatitis?

Abdominal contrast radiography
Canine pancreatic lipase (cPLI) Correct answer.
Serum lipase activity
Serum amylase activity

Explanation

Canine pancreatic lipase immunoreactivity (cPLI) is more specific for pancreatitis than amylase or lipase. Radiography may support the diagnosis by showing nonspecific changes but does not confirm pancreatitis. Clinical signs and cPLI are commonly combined to make the diagnosis.

Question 16Canine and feline (companion animal) practice

A 6-year-old dog has acute hindlimb lameness; physical examination shows cranial drawer and tibial thrust. What is the most likely diagnosis?

Hip dysplasia
Osteochondritis dissecans of the stifle
Patellar luxation
Cruciate ligament rupture Correct answer.

Explanation

Cranial drawer and tibial thrust are hallmark findings of cranial cruciate ligament rupture in the dog. Hip dysplasia causes different orthopedic signs, and patellar luxation is diagnosed by palpating the patella outside the trochlear groove. OCD of the stifle would not produce these instability tests.

Question 17Canine and feline (companion animal) practice

A cat has a systolic murmur, gallop rhythm, and echocardiographic concentric left ventricular hypertrophy. What is the most likely diagnosis?

Mitral valve dysplasia
Pericardial effusion with tamponade
Dilated cardiomyopathy
Hypertrophic cardiomyopathy Correct answer.

Explanation

Hypertrophic cardiomyopathy is characterized by concentric left ventricular hypertrophy, especially of the interventricular septum, and can cause murmurs and gallop rhythms. Dilated cardiomyopathy causes eccentric hypertrophy and systolic dysfunction, while pericardial effusion would show fluid around the heart.

Question 18Canine and feline (companion animal) practice

A 3-year-old dog has chronic pruritus affecting the paws, face, and ears, with secondary pyoderma and no fleas. Which diagnosis is most likely?

Hypothyroidism
Feline hyperesthesia syndrome
Canine atopic dermatitis Correct answer.
Sarcoptic mange

Explanation

Canine atopic dermatitis is a common pruritic allergic skin disease with predilection sites including the paws, face, ears, and ventrum. The diagnosis is clinical after ruling out parasites and secondary infections. Sarcoptic mange is intensely pruritic and contagious, but the distribution and chronic course here fit atopy.

Question 19Canine and feline (companion animal) practice

A dog with access to standing water has fever, jaundice, azotemia, and thrombocytopenia. Which organism is most likely?

Canine distemper virus infection
Ehrlichia canis
Leptospira interrogans Correct answer.
Babesia canis

Explanation

Leptospirosis often causes acute kidney injury, hepatic involvement with jaundice, fever, and thrombocytopenia, and exposure to contaminated water is a risk factor. Diagnosis is supported by PCR or serology. Distemper, babesiosis, and ehrlichiosis have different typical clinical patterns.

Question 20Canine and feline (companion animal) practice

A dog recently boarded has a harsh dry cough, retching, and mild fever; lung sounds are clear. What is the most appropriate initial management?

High-dose corticosteroids
Immediate thoracic surgery
Euthanasia discussion
Supportive care, isolation Correct answer.

Explanation

Infectious tracheobronchitis (kennel cough) is usually self-limiting and managed with supportive care, rest, and isolation from other dogs. Antibiotics are reserved for severe or complicated cases. Thoracic surgery, high-dose steroids, and euthanasia are not appropriate initial steps for mild disease.

Question 21Canine and feline (companion animal) practice

A 6-month-old Yorkshire Terrier is stunted, has postprandial lethargy, and has ammonium biurate crystals in the urine. Which diagnostic finding is most consistent with a portosystemic shunt?

Marked neutrophilic leukocytosis
Postprandial serum bile acid increase Correct answer.
Postprandial serum bile acid decrease
Hyperkalemia with hyponatremia

Explanation

Portosystemic shunts reduce hepatic clearance of bile acids, so serum bile acids are increased, especially after a meal. Ammonium biurate uroliths and poor growth are supportive findings. Hyperkalemia with hyponatremia suggests hypoadrenocorticism, and marked neutrophilia suggests inflammation or infection.

Question 22Canine and feline (companion animal) practice

A dog ingested rat poison 3 days ago and now has epistaxis and prolonged prothrombin time. Which treatment is most appropriate?

Fresh frozen plasma alone
Vitamin K1 Correct answer.
Vitamin K3
Protamine sulfate

Explanation

Anticoagulant rodenticides inhibit vitamin K epoxide reductase, causing deficiency of vitamin K-dependent clotting factors. Treatment is vitamin K1 given until clotting times normalize. Vitamin K3 is ineffective, and plasma is an adjunct for severe bleeding but does not replace prolonged vitamin K1 therapy.

Question 23Canine and feline (companion animal) practice

A cat with hypertrophic cardiomyopathy suddenly has painful, cold hindlimbs and absent femoral pulses. What is the most likely cause?

Bilateral hip luxation
Myasthenia gravis
Acute intervertebral disc extrusion
Aortic thromboembolism Correct answer.

Explanation

Aortic thromboembolism is a serious complication of feline cardiomyopathy; a thrombus lodges at the aortic trifurcation, causing acute hindlimb paresis, pain, cold limbs, and absent pulses. Treatment focuses on analgesia, heart failure management, and supportive care, with a guarded prognosis. Disc extrusion and hip luxation do not cause absent femoral pulses and cold limbs.

Question 24Canine and feline (companion animal) practice

A dog has petechiae, epistaxis, a platelet count of 12,000/µL, and prolonged buccal mucosal bleeding time. Which is most likely?

Immune-mediated thrombocytopenia Correct answer.
Rodenticide poisoning
Disseminated intravascular coagulation
Von Willebrand disease

Explanation

Severe thrombocytopenia with petechiae and prolonged mucosal bleeding time is characteristic of immune-mediated thrombocytopenia. Coagulation times are typically normal unless there is concurrent DIC. Treatment usually includes glucocorticoids and sometimes other immunosuppressive therapy.

Question 25Canine and feline (companion animal) practice

A 10-year-old cat with insulin-resistant diabetes has an enlarged jaw, weight gain, and a high IGF-1 concentration. What is the most likely diagnosis?

Diabetes insipidus
Hypersomatotropism Correct answer.
Hyperadrenocorticism
Hyperthyroidism

Explanation

Hypersomatotropism, or acromegaly, is caused by a growth hormone-secreting pituitary tumor and leads to insulin resistance, enlarged jaw or paws, and increased IGF-1. Hyperadrenocorticism and hyperthyroidism can cause insulin resistance but not this classic acromegalic appearance.

Question 26Canine and feline (companion animal) practice

A 4-year-old dog lives outdoors in a region where Dirofilaria immitis is endemic and has never received heartworm prevention. The dog is clinically healthy. Which screening test is most appropriate?

Antigen testing for Dirofilaria immitis Correct answer.
Fecal Baermann testing
Thoracic radiography alone
Microfilarial concentration testing alone

Explanation

Antigen testing detects adult female heartworm antigen and is the recommended primary screening test in dogs; microfilarial tests can be negative in occult infections. A positive antigen test should be confirmed before treatment.

Question 27Canine and feline (companion animal) practice

An unvaccinated 4-month-old puppy has fever, ocular and nasal discharge, and cough, and later develops myoclonus and hyperkeratosis of the nasal planum. Which virus is most likely responsible?

Canine adenovirus type 1
Canine distemper virus Correct answer.
Canine parvovirus type 2
Rabies virus

Explanation

Canine distemper virus causes multisystemic disease with respiratory and gastrointestinal signs, followed by neurologic signs such as myoclonus and hyperkeratosis of the nasal planum and footpads. Parvovirus primarily causes enteritis and does not produce these neurologic or cutaneous changes.

Question 28Canine and feline (companion animal) practice

A shelter cat has sneezing, conjunctivitis, and dendritic corneal ulcers. Which virus is most likely responsible?

Feline leukemia virus
Feline herpesvirus-1 Correct answer.
Feline calicivirus
Feline immunodeficiency virus

Explanation

Feline herpesvirus-1 is a major cause of feline upper respiratory disease and classically produces dendritic corneal ulcers and latent infection in the trigeminal ganglion. Calicivirus more often causes oral ulceration and less commonly corneal disease.

Question 29Canine and feline (companion animal) practice

A healthy 2-year-old cat from a multi-cat household is being screened for feline leukemia virus before adoption. Which test is most appropriate as the initial screening test?

ELISA for FeLV antigen Correct answer.
PCR for proviral DNA
Indirect immunofluorescence assay
Bone marrow cytology

Explanation

The initial screening test for FeLV is an ELISA that detects viral antigen in blood; it is sensitive and suitable for screening. Positive ELISA results in healthy cats should be confirmed with a second test such as IFA or PCR.

Question 30Canine and feline (companion animal) practice

A 1-year-old Labrador retriever has hindlimb lameness and difficulty rising; radiographs show shallow acetabula with femoral head subluxation. What is the most likely diagnosis?

Hip dysplasia Correct answer.
Cranial cruciate ligament rupture
Panosteitis
Legg-Calvé-Perthes disease

Explanation

Hip dysplasia is a developmental disorder characterized by hip joint laxity, shallow acetabula, and secondary osteoarthritis, typically affecting young large-breed dogs. Legg-Calvé-Perthes causes femoral head necrosis in small breeds, and cruciate rupture causes cranial drawer rather than acetabular shallowness.

Question 31Canine and feline (companion animal) practice

A large-breed dog has acute nonproductive retching, a distended abdomen, and tachycardia. What is the most appropriate immediate management?

Gastric decompression and IV fluid therapy Correct answer.
Perform abdominal ultrasound before any treatment
Start broad-spectrum antibiotics alone
Administer oral activated charcoal

Explanation

Gastric dilatation-volvulus is a surgical emergency; immediate priorities are intravenous fluid resuscitation and gastric decompression, followed by surgery. Delay for imaging or giving oral medication worsens the risk of necrosis and shock.

Question 32Canine and feline (companion animal) practice

A puppy has a potbellied appearance and diarrhea, and a fecal flotation shows roundworm eggs. Which anthelmintic is most appropriate?

Metronidazole for protozoa
Clindamycin (antibiotic)
Pyrantel pamoate Correct answer.
Praziquantel (antitapeworm)

Explanation

Pyrantel pamoate is effective against common canine roundworms and hookworms and is commonly used in puppies. Metronidazole treats protozoal and anaerobic infections, while praziquantel targets tapeworms.

Question 33Canine and feline (companion animal) practice

A 7-year-old overweight Pomeranian has a chronic honking cough that worsens with excitement. Radiographs show diffuse narrowing of the intrathoracic trachea. What is the most likely diagnosis?

Tracheal collapse Correct answer.
Chronic bronchitis
Laryngeal paralysis
Kennel cough

Explanation

Tracheal collapse classically causes a goose-honk cough in small-breed dogs, exacerbated by excitement or pressure on the neck, with radiographic or fluoroscopic narrowing of the trachea. Chronic bronchitis causes a softer cough with bronchial thickening rather than tracheal narrowing.

Question 34Canine and feline (companion animal) practice

A 12-year-old cat has weight loss despite a good appetite, tachycardia, and a palpable cervical mass. Serum total thyroxine is high. What is the most likely diagnosis?

Hyperthyroidism Correct answer.
Diabetes mellitus
Acromegaly
Chronic kidney disease

Explanation

Hyperthyroidism in cats causes weight loss with polyphagia, tachycardia, and often a palpable thyroid nodule; high total T4 confirms the diagnosis. Diabetes mellitus causes polyuria and polydipsia, and acromegaly is less common and associated with insulin resistance and enlarged extremities.

Question 35Canine and feline (companion animal) practice

A 6-year-old spayed dog has weight gain, lethargy, bilateral symmetrical alopecia, and bradycardia. Total T4 is low and TSH is high. What is the most likely diagnosis?

Hypothyroidism Correct answer.
Diabetes mellitus
Hyperadrenocorticism
Hypoadrenocorticism

Explanation

Primary hypothyroidism typically produces weight gain, lethargy, symmetric alopecia, and bradycardia, with low T4 and elevated TSH. Hyperadrenocorticism causes polyuria, polydipsia, and a potbellied appearance, while hypoadrenocorticism causes weakness, vomiting, and electrolyte abnormalities.

Question 36Canine and feline (companion animal) practice

An 8-year-old intact female dog is presented 6 weeks after estrus with purulent vaginal discharge, fever, and leukocytosis. What is the definitive treatment?

Repeat breeding
Ovariohysterectomy Correct answer.
Antibiotics alone
Prostaglandin F2α alone

Explanation

Pyometra is a uterine infection with accumulation of pus; ovariohysterectomy is the definitive treatment and removes the source of infection. Antibiotics alone or prostaglandins may be used only in selected breeding animals and carry a risk of recurrence or rupture.

Question 37Canine and feline (companion animal) practice

A 5-year-old dog has a painful red eye, corneal edema, a dilated pupil, and an intraocular pressure of 45 mmHg. What is the most likely diagnosis?

Anterior uveitis
Glaucoma Correct answer.
Conjunctivitis
Keratoconjunctivitis sicca

Explanation

Glaucoma is characterized by elevated intraocular pressure, a dilated pupil, corneal edema, and pain; normal IOP is roughly 10 to 20 mmHg. Uveitis often causes a constricted pupil and low or normal pressure.

Question 38Canine and feline (companion animal) practice

A 9-year-old dog has polyuria, polydipsia, a pendulous abdomen, and thin skin. Urine cortisol:creatinine ratio is elevated, and low-dose dexamethasone suppression shows no suppression. What is the most likely diagnosis?

Hypoadrenocorticism (Addison)
Hypothyroidism
Diabetes mellitus with ketoacidosis
Hyperadrenocorticism Correct answer.

Explanation

Hyperadrenocorticism causes polyuria, polydipsia, pendulous abdomen, thin skin, and failure to suppress cortisol on low-dose dexamethasone testing. Hypothyroidism and diabetes mellitus can cause some similar signs but do not produce these cortisol test results.

Question 39Canine and feline (companion animal) practice

A 9-year-old dog has had a chronic cough for 4 months. Radiographs show bronchial thickening, and bronchoalveolar lavage shows neutrophilic inflammation without infectious organisms. What is the most likely diagnosis?

Heartworm infection
Chronic bronchitis Correct answer.
Kennel cough
Tracheal collapse syndrome

Explanation

Chronic bronchitis is diagnosed by chronic cough with bronchial thickening and neutrophilic airway inflammation after infectious and parasitic causes are excluded. Kennel cough is acute and infectious, and heartworm disease would be identified by antigen testing.

Question 40Canine and feline (companion animal) practice

A 3-year-old dog has regurgitation, weight loss, and aspiration pneumonia. Radiographs show a dilated esophagus. Which management is most appropriate?

Give oral prokinetics with every meal
Withhold food for 48 hours
Free access to dry food and water all day
Elevated feeding of small frequent meals Correct answer.

Explanation

Megaesophagus is managed by feeding small, frequent meals with the dog in an elevated position to reduce regurgitation and aspiration risk. Free access to food and water increases aspiration risk, and prokinetics are not uniformly effective.

Question 41Canine and feline (companion animal) practice

An 8-year-old Cavalier King Charles Spaniel has a left apical systolic murmur, cough, and exercise intolerance. Echocardiography shows mitral regurgitation and left atrial enlargement. What is the most likely diagnosis?

Pulmonic stenosis
Hypertrophic cardiomyopathy
Dilated cardiomyopathy
Myxomatous mitral disease Correct answer.

Explanation

Myxomatous mitral valve disease is the most common acquired heart disease in small-breed dogs and causes a left apical systolic murmur with mitral regurgitation and left atrial enlargement. Hypertrophic cardiomyopathy is primarily a feline disease, and pulmonic stenosis causes a left basilar murmur.

Question 42Canine and feline (companion animal) practice

A dog has fever, epistaxis, thrombocytopenia, and a history of tick exposure. Morulae are seen within monocytes. Which organism is most likely responsible?

Borrelia burgdorferi
Babesia canis
Ehrlichia canis Correct answer.
Anaplasma phagocytophilum

Explanation

Ehrlichia canis infects monocytes and produces fever, thrombocytopenia, and bleeding tendencies after tick exposure; morulae may be seen in monocytes. Anaplasma phagocytophilum typically forms morulae in neutrophils, and Babesia causes hemolysis.

Question 43Canine and feline (companion animal) practice

A cat has anorexia, lethargy, and vomiting. Feline pancreatic lipase immunoreactivity is markedly elevated. What is the most likely diagnosis?

Pancreatitis Correct answer.
Cholangiohepatitis
Chronic kidney disease
Inflammatory bowel disease

Explanation

Elevated feline pancreatic lipase immunoreactivity supports pancreatitis, which often causes nonspecific anorexia, lethargy, and vomiting in cats. Cholangiohepatitis and inflammatory bowel disease can coexist but are not identified by this specific test.

Question 44Canine and feline (companion animal) practice

A 5-year-old dog has generalized lymphadenopathy. Lymph node cytology shows a monotonous population of large lymphoid cells. What is the most likely diagnosis?

Leukemia
Reactive lymphoid hyperplasia
Lymphoma Correct answer.
Mast cell tumor

Explanation

Lymphoma is diagnosed by finding a uniform population of large atypical lymphoid cells in an enlarged lymph node. Reactive hyperplasia would show mixed cell types and normal architecture rather than a monotonous malignant population.

Question 45Canine and feline (companion animal) practice

A postpartum small-breed dog has tetany, muscle tremors, and seizures. Serum calcium is 6 mg/dL. What is the most appropriate treatment?

Intravenous diazepam alone
Intravenous glucose
Oral calcium supplementation alone
Intravenous calcium gluconate Correct answer.

Explanation

Eclampsia is caused by hypocalcemia in the postpartum period; intravenous calcium gluconate is the specific treatment, given cautiously while monitoring for bradycardia. Diazepam may control seizures but does not correct the underlying hypocalcemia.

Question 46Canine and feline (companion animal) practice

A male cat has stranguria, vocalization, and a hard bladder. An ECG shows bradycardia with peaked T waves. What is the most appropriate immediate management?

Perform cystocentesis without stabilization
Give furosemide and oral potassium
Start antibiotics and send urine for culture
IV calcium and relieve the obstruction Correct answer.

Explanation

Urethral obstruction causes hyperkalemia, which can produce bradycardia and peaked T waves; intravenous calcium protects the myocardium while the obstruction is relieved. Cystocentesis or antibiotics without relieving the obstruction does not address the life-threatening electrolyte disturbance.

Question 47Canine and feline (companion animal) practice

A young cat has persistent fever, weight loss, and ascites. Serum globulins are high, and PCR on the effusion is positive for feline coronavirus. What is the most likely diagnosis?

Feline infectious peritonitis Correct answer.
Feline leukemia virus infection
Toxoplasmosis
Lymphoma

Explanation

Feline infectious peritonitis is caused by a mutated feline coronavirus and classically produces persistent fever, weight loss, effusion, and hyperglobulinemia in young cats. A positive coronavirus PCR on effusion supports FIP when combined with compatible clinical findings.

Question 48Canine and feline (companion animal) practice

An 8-year-old German Shepherd has progressive hindlimb ataxia and proprioceptive deficits without pain. Myelography is normal. What is the most likely diagnosis?

Fibrocartilaginous embolism
Degenerative myelopathy Correct answer.
Intervertebral disc disease
Hip dysplasia

Explanation

Degenerative myelopathy causes slowly progressive, nonpainful hindlimb ataxia and proprioceptive loss in older large-breed dogs, with normal myelography. Intervertebral disc disease and fibrocartilaginous embolism are typically acute or painful, and hip dysplasia causes pain and lameness rather than progressive myelopathy.

Question 49Canine and feline (companion animal) practice

A 10-year-old dog has hypercalcemia and a firm perianal mass. Biopsy shows a neuroendocrine tumor. What is the most likely diagnosis?

Lymphoma (multicentric)
Anal sac adenocarcinoma Correct answer.
Mast cell tumor (cutaneous)
Perianal adenoma (benign)

Explanation

Anal sac apocrine gland adenocarcinoma is a neuroendocrine tumor that often causes hypercalcemia and a perianal mass in older dogs. Perianal adenomas are androgen-dependent and usually benign, without hypercalcemia.

Question 50Canine and feline (companion animal) practice

An obese cat stops eating for 1 week and becomes icteric. Ultrasound shows a diffusely echogenic, enlarged liver. What is the most likely diagnosis?

Hepatic lipidosis Correct answer.
Cholangiohepatitis
Pancreatitis
Feline infectious peritonitis

Explanation

Hepatic lipidosis is a common cause of icterus in obese cats after a period of anorexia, with diffuse hepatic lipid accumulation. Cholangiohepatitis and pancreatitis can also cause icterus but have different imaging and clinical features.