NAVLE General Practice 4 — Questions and Answers
Question 1: A 4-year-old ferret presents with muscle wasting, hindlimb weakness, and hypoglycemia (blood glucose 40 mg/dL) that resolves with dextrose. The most likely diagnosis is:
- Insulinoma (Correct answer)
- Adrenal gland disease
- Aleutian disease
- Lymphoma
Correct answer: Insulinoma
Insulinoma is the most common pancreatic tumor in ferrets over 3 years old and classically causes fasting hypoglycemia, weakness, and neurological signs relieved by glucose administration.
Question 2: A dog presents with acute onset of right-sided head tilt, nystagmus with the fast phase to the left, and rolling. MRI is normal. The most likely diagnosis is:
- Idiopathic vestibular syndrome (Correct answer)
- Otitis interna
- Cerebellar stroke
- Brainstem neoplasia
Correct answer: Idiopathic vestibular syndrome
Idiopathic (geriatric) vestibular syndrome presents with acute severe peripheral vestibular signs and a normal MRI, and typically resolves spontaneously within 72 hours to 2 weeks.
Question 3: During a pre-purchase exam of a 5-year-old Quarter Horse, grade 3/5 left forelimb lameness is localized to the foot with a palmar digital nerve block. Radiographs reveal navicular bone erosions and synovial invaginations. The diagnosis is:
- Navicular syndrome (palmar foot pain) (Correct answer)
- Pedal osteitis
- Distal phalanx fracture
- Laminitis with rotation
Correct answer: Navicular syndrome (palmar foot pain)
Navicular syndrome is characterized by palmar foot pain, positive response to palmar digital nerve block, and radiographic changes including synovial fossae and flexor cortex erosions of the navicular bone.
Question 4: A cat presents with open-mouth breathing, muffled heart sounds, and dull ventral lung sounds. Thoracocentesis yields chylous fluid. The most common underlying cause in cats is:
- Cardiac disease (cardiomyopathy)
- Thoracic duct trauma
- Mediastinal lymphoma
- Idiopathic chylothorax (Correct answer)
Correct answer: Idiopathic chylothorax
Idiopathic chylothorax is the most common cause in cats, though cardiac disease and neoplasia must be ruled out; true idiopathic cases have no identifiable underlying disorder.
Question 5: A goat kid presents at 2 days of age with failure to nurse, profuse watery diarrhea, and rapid dehydration. Feces are negative for Cryptosporidium and E. coli. Rotavirus ELISA is positive. Treatment priorities include:
- Oral electrolyte fluid therapy and supportive care (Correct answer)
- Sulfonamide antibiotics and probiotics
- Anthelmintic deworming
- Corticosteroids to reduce intestinal inflammation
Correct answer: Oral electrolyte fluid therapy and supportive care
Rotavirus diarrhea in neonatal ruminants is managed supportively with oral electrolyte replacement because the disease is viral and antibiotics are ineffective; correction of dehydration is paramount.
Question 6: A 9-year-old dog with a 3-week history of polyuria/polydipsia has a urine specific gravity of 1.008, sodium of 158 mEq/L, and fails to concentrate urine after water deprivation but responds to exogenous ADH. The diagnosis is:
- Central diabetes insipidus (Correct answer)
- Nephrogenic diabetes insipidus
- Psychogenic polydipsia
- Hyperadrenocorticism
Correct answer: Central diabetes insipidus
Central diabetes insipidus is confirmed when the patient fails the water deprivation test but concentrates urine in response to exogenous ADH (desmopressin), indicating a lack of endogenous ADH production.
Question 7: A pig farm reports sudden death in 3-week-old piglets with gross necropsy findings of fibrinous polyserositis, arthritis, and meningitis. The most likely causative agent is:
- Haemophilus parasuis (Glässer's disease) (Correct answer)
- Streptococcus suis type 2
- Mycoplasma hyorhinis
- Actinobacillus pleuropneumoniae
Correct answer: Haemophilus parasuis (Glässer's disease)
Haemophilus parasuis causes Glässer's disease in young pigs, characterized by fibrinous polyserositis (peritonitis, pleuritis, pericarditis), arthritis, and meningitis at 3–8 weeks of age.
NAVLE General Practice 4
A 4-year-old ferret presents with muscle wasting, hindlimb weakness, and hypoglycemia (blood glucose 40 mg/dL) that resolves with dextrose.
The most likely diagnosis is: