NAVLE Canine Internal Medicine 3 — Questions and Answers
Question 1: A 12-year-old Miniature Schnauzer presents with hypercalcemia (Ca 14.2 mg/dL), weight loss, and peripheral lymphadenopathy. Which test is most useful to differentiate hypercalcemia of malignancy from primary hyperparathyroidism?
- Serum phosphorus
- PTH and PTHrP assay (Correct answer)
- Ionized calcium
- Urinary calcium:creatinine ratio
Correct answer: PTH and PTHrP assay
Measuring both PTH (elevated in hyperparathyroidism) and PTHrP (elevated in humoral hypercalcemia of malignancy) is the most direct way to distinguish these causes.
Question 2: A 6-year-old Shar-Pei presents with fever, swollen hocks, and elevated SAA. Renal biopsy shows amyloid deposition in the medullary interstitium. Which treatment has shown the most benefit in slowing renal amyloidosis progression in this breed?
- Prednisone
- Colchicine (Correct answer)
- Cyclosporine
- Mycophenolate mofetil
Correct answer: Colchicine
Colchicine inhibits amyloid fibril formation and has been shown to slow progression of renal amyloidosis in Shar-Peis when started early.
Question 3: An 8-year-old Dachshund presents with acute onset of severe back pain and inability to ambulate. MRI confirms acute thoracolumbar IVDD at T12-13. Deep pain perception is absent. Within what time frame should surgical decompression ideally occur to maximize neurological recovery?
- Within 48 hours (Correct answer)
- Within 24 hours
- Within 4 hours
- Within 6 hours
Correct answer: Within 48 hours
Surgical decompression within 48 hours of loss of deep pain perception is associated with the best neurological outcomes in acute IVDD.
Question 4: A 5-year-old Labrador Retriever presents with acute onset hemolytic anemia (PCV 14%, spherocytes on smear, positive Coombs test). Which treatment combination is most appropriate as initial therapy?
- Prednisone alone
- Prednisone + azathioprine or mycophenolate (Correct answer)
- Cyclosporine alone
- Dexamethasone + vincristine
Correct answer: Prednisone + azathioprine or mycophenolate
Combination immunosuppression with a corticosteroid plus a steroid-sparing agent (azathioprine or mycophenolate) is recommended for IMHA to reduce relapse rates.
Question 5: A 7-year-old Doberman Pinscher presents with exercise intolerance, ascites, and a gallop rhythm. Echocardiography shows a dilated left ventricle with reduced fractional shortening of 12%. What is the most likely diagnosis?
- Hypertrophic cardiomyopathy
- Dilated cardiomyopathy (Correct answer)
- Mitral valve endocardiosis
- Pericardial effusion
Correct answer: Dilated cardiomyopathy
Dilated cardiomyopathy with reduced fractional shortening and a dilated left ventricle is the classic presentation in Dobermans.
Question 6: A 9-year-old Cairn Terrier has chronic hepatitis with copper accumulation on liver biopsy (>2000 µg/g dry weight). Which chelation agent is most commonly used in dogs to reduce hepatic copper?
- Deferasirox
- D-penicillamine (Correct answer)
- Deferoxamine
- EDTA
Correct answer: D-penicillamine
D-penicillamine is the most widely used copper chelator in dogs with copper-associated hepatopathy, mobilizing hepatic copper for urinary excretion.
Question 7: A 2-year-old Border Collie presents with episodic muscle tremors and facial rubbing after exercise. Ionized calcium is 0.78 mmol/L (normal 1.12–1.40). Which condition is the most common cause of hypocalcemia in young adult dogs?
- Primary hypoparathyroidism
- Eclampsia (puerperal tetany) (Correct answer)
- Vitamin D deficiency
- Chronic renal failure
Correct answer: Eclampsia (puerperal tetany)
Eclampsia due to calcium loss through milk production in periparturient females is the most common cause of acute hypocalcemia in young adult dogs.
NAVLE Canine Internal Medicine 3
A 12-year-old Miniature Schnauzer presents with hypercalcemia (Ca 14.2 mg/dL), weight loss, and peripheral lymphadenopathy.
Which test is most useful to differentiate hypercalcemia of malignancy from primary hyperparathyroidism?