NAVLE Canine Internal Medicine 5

Question 1

A 7-year-old intact male Golden Retriever presents with polyuria, polydipsia, and a pendulous abdomen. Bloodwork reveals mild hyperglycemia, elevated ALP, and hypokalemia. Urine cortisol:creatinine ratio is elevated. A low-dose dexamethasone suppression test fails to suppress cortisol at 8 hours. An ACTH stimulation test shows an exaggerated response. Abdominal ultrasound reveals bilateral adrenal enlargement. Which additional finding would most strongly suggest concurrent occult neoplasia rather than PDH alone?

Accepted Answer

Neurological signs with a pituitary mass > 1 cm on MRI

Answer

A pituitary macroadenoma (> 1 cm) detected on MRI in a dog with PDH indicates a large pituitary tumor that carries a worse prognosis and may cause neurological signs (circling, behavior change, blindness). This is distinct from a microadenoma and strongly shifts management toward radiation therapy in addition to or instead of medical adrenal blockade. Elevated ALP, UTI, and failure to suppress at 4 hours are all common features of PDH itself and do not specifically indicate concurrent occult neoplasia.

Question 2

A 5-year-old Labrador Retriever is presented with acute collapse and hematemesis. On exam, the dog is tachycardic (HR 160 bpm), pale, and has a fluid wave on abdominal ballottement. PCV is 18%, total protein is 3.2 g/dL, and abdominal ultrasound reveals a large splenic mass with free abdominal fluid. After stabilization, a splenectomy is performed. Histopathology confirms splenic hemangiosarcoma. Which combination of prognostic factors is associated with the LONGEST median survival time post-splenectomy?

Accepted Answer

Stage I disease with adjuvant doxorubicin chemotherapy

Answer

Splenic hemangiosarcoma staged as Stage I (tumor confined to spleen, no rupture, no metastasis) combined with adjuvant doxorubicin-based chemotherapy is associated with the longest median survival — approximately 4–6 months compared to 1–2 months with surgery alone. Stage II (ruptured or with regional spread) and Stage III (distant metastasis) carry significantly worse prognoses regardless of protocol. VAC has not consistently outperformed single-agent doxorubicin in canine HSA.

Question 3

A 9-year-old spayed female Cocker Spaniel presents with progressive exercise intolerance, a 3/6 left apical systolic murmur, and radiographic evidence of left atrial enlargement without pulmonary edema. Echocardiography confirms myxomatous mitral valve disease (MMVD) with a left atrial-to-aortic root ratio (LA:Ao) of 1.7. Which management decision is most consistent with current ACVIM consensus guidelines for this patient?

Accepted Answer

Begin pimobendan immediately to delay onset of congestive heart failure

Answer

Per the 2019 ACVIM consensus guidelines for MMVD (EPIC trial criteria), dogs in Stage B2 — defined as radiographic cardiomegaly OR LA:Ao ≥ 1.7 on echo — should be started on pimobendan to delay onset of CHF. An LA:Ao of 1.7 meets the echocardiographic threshold for Stage B2, making pimobendan initiation appropriate now. Enalapril was not shown to significantly delay CHF onset in Stage B dogs in the SVEP trial. Furosemide is reserved for Stage C (active CHF) and should not be used prophylactically.

Question 4

A 4-year-old male Shar-Pei presents with recurrent fever episodes lasting 1–3 days, swollen hocks, and intermittent vomiting. Between episodes the dog appears normal. CBC and chemistry during a febrile episode show neutrophilia with a left shift and mildly elevated BUN. Urinalysis shows 3+ proteinuria. Which underlying pathophysiologic mechanism is most directly responsible for the proteinuria in this dog?

Accepted Answer

Renal amyloid A deposition in glomeruli and medullary interstitium leading to nephrotic syndrome

Answer

Shar-Peis are predisposed to Shar-Pei Autoinflammatory Disease (SPAID), formerly called Familial Shar-Pei Fever, caused by dysregulation of the inflammasome with markedly elevated IL-6 and IL-18. Chronic inflammation drives sustained serum amyloid A (SAA) production. SAA fibrils deposit as reactive amyloid A (AA amyloidosis) preferentially in the renal medullary interstitium and glomeruli in Shar-Peis, causing progressive proteinuria and eventual renal failure — a pattern distinct from other breeds where hepatic deposition predominates. Immune-complex GN is a feature of some breeds but is not the primary mechanism in SPAID-associated renal disease.

Question 5

A 6-year-old spayed female Doberman Pinscher presents with a 2-week history of anorexia, weight loss, and ascites. Physical exam reveals icterus and hepatomegaly. Bloodwork: ALT 850 U/L, ALP 340 U/L, total bilirubin 6.2 mg/dL, albumin 1.8 g/dL, glucose 58 mg/dL. Coagulation panel: PT prolonged, PTT prolonged, fibrinogen low, D-dimer elevated. Abdominal ultrasound shows a nodular liver with portal hypertension. Liver cytology via ultrasound-guided FNA shows hepatocytes with intracytoplasmic copper granules. Which statement about copper-associated hepatopathy in Dobermans is MOST accurate?

Accepted Answer

Hepatic copper concentrations in affected Dobermans are typically highest in periportal zones (zone 1), unlike Bedlingtons where zone 3 is predominant

Answer

Copper-associated hepatopathy in Doberman Pinschers demonstrates a periportal (zone 1) distribution of copper accumulation on rhodanine or rubeanic acid staining, which is a key histologic distinguishing feature from Bedlington Terrier copper toxicosis (where copper accumulates in centrilobular/zone 3 hepatocytes). Bedlington Terriers carry COMMD1 mutations; Dobermans have a separate, incompletely characterized genetic basis. The primary vs. secondary distinction remains debated in Dobermans, but their pattern of copper distribution is diagnostically and mechanistically distinct from Bedlingtons.

NAVLE - North American Veterinary Licensing Examination Practice Test

NAVLE - North American Veterinary Licensing Examination Practice Test

NAVLE Canine Internal Medicine 5