NAVLE Canine Medicine and Surgery Questions and Answers

Question 1

A 5-year-old, male neutered Doberman Pinscher presents for evaluation. Echocardiography reveals a dilated left ventricle with decreased fractional shortening. The owner reports episodes of coughing and exercise intolerance. Which of the following long-term oral medications has been shown to delay the onset of clinical signs and extend the life of Dobermans in the occult stage of this disease?

Accepted Answer

Pimobendan

Answer

Pimobendan, an inodilator, has been proven to delay the onset of congestive heart failure and prolong survival in Doberman Pinschers with preclinical (occult) dilated cardiomyopathy (DCM). While furosemide, enalapril, and spironolactone are used to manage congestive heart failure once it develops, pimobendan is the key therapy for the occult stage.

Question 2

A 10-week-old female Maltese puppy is presented for her first physical examination. On auscultation, you detect a continuous, 'machinery-like' murmur, heard best over the left heart base. The puppy is otherwise bright and alert. Which of the following is the most likely diagnosis?

Accepted Answer

Patent Ductus Arteriosus

Answer

A continuous, machinery-like murmur heard best at the left heart base in a young dog is pathognomonic for a left-to-right shunting Patent Ductus Arteriosus (PDA). This occurs because the ductus arteriosus, a vessel that bypasses the lungs in the fetus, fails to close after birth, causing a constant flow of blood from the high-pressure aorta to the lower-pressure pulmonary artery.

Question 3

A 4-year-old female spayed Standard Poodle presents with a 2-day history of lethargy, vomiting, and weakness. Physical exam reveals pale mucous membranes and tachycardia. A CBC shows a hematocrit of 15% with marked spherocytosis and autoagglutination. What is the MOST critical initial component of immunosuppressive therapy for this dog's condition?

Accepted Answer

Glucocorticoids

Answer

The clinical signs and laboratory findings are highly suggestive of Immune-Mediated Hemolytic Anemia (IMHA). The cornerstone and first-line treatment for IMHA is aggressive immunosuppression, which is most rapidly and effectively achieved with glucocorticoids (e.g., prednisone or dexamethasone). While other immunosuppressive drugs like azathioprine, cyclosporine, and mycophenolate are often used as adjuncts, they are not the primary, initial therapy.

Question 4

Which of the following findings on an ACTH stimulation test is most consistent with a diagnosis of typical hypoadrenocorticism (Addison's disease) in a dog?

Accepted Answer

Low baseline cortisol with a minimal to no response post-ACTH

Answer

The definitive diagnosis of hypoadrenocorticism is made with an ACTH stimulation test. Dogs with Addison's disease have adrenal glands that cannot produce cortisol, so both the baseline (pre-ACTH) cortisol level and the post-ACTH cortisol level will be low, showing a minimal or flat-line response to stimulation.

Question 5

A 7-year-old, neutered male Golden Retriever is presented with a chief complaint of weight gain, lethargy, and a 'rat tail' (alopecia on the tail). Physical examination reveals a dull coat, truncal alopecia, and mild obesity. Which of the following clinicopathologic abnormalities would be most supportive of a diagnosis of hypothyroidism?

Accepted Answer

Hypercholesterolemia

Answer

The clinical signs described are classic for canine hypothyroidism. Due to the decreased metabolic rate associated with hypothyroidism, hypercholesterolemia is a very common finding on a serum biochemistry panel, present in about 75% of cases. While a mild, non-regenerative anemia may also be seen, hypercholesterolemia is the most consistent biochemical abnormality.

NAVLE - North American Veterinary Licensing Examination Practice Test

NAVLE - North American Veterinary Licensing Examination Practice Test

NAVLE Canine Medicine and Surgery Questions and Answers