AAVSB - American Association of Veterinary State Boards Internal Medicine by Species Questions and Answers — Questions and Answers
Question 1: A 4-year-old female spayed Standard Poodle presents with a 2-day history of lethargy, vomiting, and weakness. Physical examination reveals dehydration and bradycardia. Initial bloodwork shows hyponatremia and hyperkalemia, with a Na:K ratio of 22:1. Which of the following is the most definitive diagnostic test for the suspected condition?
- Endogenous ACTH measurement
- Dexamethasone suppression test
- ACTH stimulation test (Correct answer)
- Baseline cortisol level
Correct answer: ACTH stimulation test
The clinical signs (lethargy, vomiting, weakness), physical exam findings (dehydration, bradycardia), and classic electrolyte abnormalities (hyponatremia, hyperkalemia, Na:K ratio < 27:1) are highly suggestive of hypoadrenocorticism (Addison's disease). The ACTH stimulation test is the gold standard for confirming the diagnosis. A baseline cortisol can be used as a screening tool to rule out Addison's, but it cannot definitively diagnose it. Dexamethasone suppression tests are used to diagnose hyperadrenocorticism (Cushing's disease), and endogenous ACTH helps differentiate pituitary-dependent from adrenal-dependent Cushing's.
Question 2: A 12-year-old Domestic Shorthair cat is presented with a 3-month history of progressive weight loss despite a ravenous appetite. The owner also reports increased vocalization and occasional vomiting. On physical exam, you note a heart rate of 240 bpm and a palpable nodule in the cervical region. What is the most likely diagnosis?
- Chronic kidney disease
- Diabetes mellitus
- Hyperthyroidism (Correct answer)
- Inflammatory bowel disease
Correct answer: Hyperthyroidism
The combination of weight loss with polyphagia, hyperactivity/vocalization, tachycardia, and a palpable thyroid nodule are classic clinical signs for feline hyperthyroidism. While diabetes mellitus can cause weight loss and polyphagia, it is typically associated with polyuria and polydipsia. Chronic kidney disease and inflammatory bowel disease usually present with weight loss and anorexia or variable appetite, not a ravenous one.
Question 3: A 10-year-old Morgan gelding presents with a 'cresty neck,' generalized obesity (BCS 8/9), and a history of recurrent laminitis. Which of the following is the most appropriate initial diagnostic approach to confirm Equine Metabolic Syndrome (EMS)?
- Thyroid-releasing hormone (TRH) stimulation test
- Fasting blood glucose and insulin levels (Correct answer)
- Abdominal radiographs to assess for enteroliths
- A complete blood count (CBC) and serum chemistry panel
Correct answer: Fasting blood glucose and insulin levels
Equine Metabolic Syndrome (EMS) is characterized by insulin dysregulation, obesity or regional adiposity (like a cresty neck), and an increased risk of laminitis. The initial and most common screening test for EMS involves measuring baseline (fasting) blood glucose and insulin concentrations. An oral sugar test may be required for a more definitive diagnosis if baseline levels are equivocal. A TRH stimulation test is used for diagnosing Pituitary Pars Intermedia Dysfunction (PPID), while a CBC/chemistry panel and radiographs are not specific for EMS.
Question 4: A dairy cow in her third week of lactation presents with decreased milk production, anorexia, and a preference for hay over grain. You notice a faint, sweet smell on her breath. A cow-side test confirms the presence of ketones in her urine. Which treatment is considered the standard oral therapy for this condition?
- Intravenous dextrose
- Propylene glycol (Correct answer)
- Vitamin B12 injection
- Oral calcium supplementation
Correct answer: Propylene glycol
The clinical signs and presence of ketonuria are indicative of bovine ketosis, a common metabolic disease in early lactation dairy cows caused by a negative energy balance. The standard and most effective oral treatment is the administration of a glucose precursor, such as propylene glycol, to help re-establish normal blood glucose levels. Intravenous dextrose is typically reserved for more severe cases. Vitamin B12 can be a useful adjunct therapy but is not the primary treatment. Oral calcium is used for hypocalcemia (milk fever).
Question 5: A goat from a large herd presents with a large, firm, non-painful abscess on its right prescapular lymph node. The owner reports that several other goats in the herd have similar swellings. A fine-needle aspirate reveals thick, caseous, odorless pus. What is the most definitive method to diagnose Caseous Lymphadenitis (CL)?
- Serological testing (SHI test)
- Gram stain of the aspirate
- Bacterial culture of the purulent material (Correct answer)
- Ultrasound of the affected lymph node
Correct answer: Bacterial culture of the purulent material
Caseous Lymphadenitis (CL), caused by Corynebacterium pseudotuberculosis, is characterized by abscesses in external and/or internal lymph nodes. While the clinical presentation is highly suggestive, the definitive diagnosis is achieved through bacterial culture of the purulent material from an intact abscess. Serology can be useful for herd screening but may produce false negatives in early infection or false positives due to exposure without active disease. A Gram stain can suggest the bacterial type but is not definitive, and ultrasound confirms the abscess but not the etiologic agent.
Question 6: A recently acquired Amazon parrot is presented for lethargy, anorexia, and bright green droppings ('biliverdinuria'). Physical examination reveals nasal and ocular discharge. The owner, who also feels unwell with flu-like symptoms, mentions the bird was stressed during transport. Which of the following zoonotic diseases should be at the top of the differential list?
- Avian influenza
- Newcastle disease
- Aspergillosis
- Avian Chlamydiosis (Psittacosis) (Correct answer)
Correct answer: Avian Chlamydiosis (Psittacosis)
The combination of non-specific signs of illness (lethargy, anorexia), respiratory signs (nasal/ocular discharge), and characteristic lime-green urates in a stressed psittacine bird is highly suggestive of Avian Chlamydiosis, caused by Chlamydia psittaci. Importantly, this disease is zoonotic and can cause 'parrot fever' in humans, presenting as atypical pneumonia with flu-like symptoms, which matches the owner's history.
AAVSB - American Association of Veterinary State Boards Internal Medicine by Species Questions and Answers
A 4-year-old female spayed Standard Poodle presents with a 2-day history of lethargy, vomiting, and weakness.
Physical examination reveals dehydration and bradycardia.
Initial bloodwork shows hyponatremia and hyperkalemia, with a Na:K ratio of 22:1.
Which of the following is the most definitive diagnostic test for the suspected condition?