Canine Medicine and Surgery Flashcards

A dog presents with a rapidly growing subcutaneous mass on the trunk. Fine needle aspirate shows granules that stain metachromatically with toluidine blue. What is the diagnosis and recommended initial treatment?

Answer: Mast cell tumor; wide surgical excision with 2-3 cm margins

Mast cell tumors contain metachromatic granules and require wide surgical margins of 2-3 cm laterally and one fascial plane deep to reduce local recurrence.

A 2-year-old female Weimaraner presents with recurrent urinary tract infections despite appropriate antibiotic therapy. Vaginal examination reveals a band of tissue at the vestibulovaginal junction. What is the likely diagnosis?

Answer: Vestibulovaginal stenosis (vaginal stricture)

Vestibulovaginal stenosis creates a pool of urine anterior to the stricture that acts as a reservoir for bacterial colonization, causing recurrent UTIs.

A dog is diagnosed with leptospirosis after exposure to wildlife. Which organ system is MOST commonly affected, leading to the clinical presentation seen in acute leptospirosis?

Answer: Renal and hepatic systems

Leptospira organisms have a particular tropism for renal tubular epithelium and hepatocytes, leading to acute kidney injury and hepatopathy as the dominant clinical syndrome.

A 9-year-old male neutered Golden Retriever presents with progressive forelimb lameness. Radiographs of the shoulder reveal a 'moth-eaten' lytic lesion of the proximal humerus with periosteal reaction and cortical destruction. What is the most likely diagnosis and treatment?

Answer: Osteosarcoma; limb amputation with adjuvant carboplatin chemotherapy

Osteosarcoma most commonly affects the proximal humerus in large breeds; amputation combined with carboplatin or doxorubicin chemotherapy provides the best median survival.

A 7-year-old Poodle presents with a PCV of 18%, MCV of 110 fL (macrocytosis), and a low serum cobalamin (B12). What is the most likely cause?

Answer: Cobalamin deficiency causing megaloblastic anemia

Cobalamin deficiency impairs DNA synthesis in RBC precursors, causing large, immature red cells (macrocytosis) and non-regenerative megaloblastic anemia.

During a routine physical exam, a 4-month-old Bulldog puppy is noted to have a heart murmur. Echocardiography reveals obstruction of the right ventricular outflow tract and right ventricular hypertrophy. What is the definitive therapy?

Answer: Balloon valvuloplasty via cardiac catheterization

Balloon valvuloplasty is the treatment of choice for pulmonic stenosis in dogs, providing effective relief of the outflow obstruction with low morbidity.

A 3-year-old intact male dog presents with a draining tract near the anus with recurrent abscesses. Probing reveals a communication with the rectum. What is this condition?

Answer: Perianal fistula (anal furunculosis)

Perianal fistulas (anal furunculosis) are chronic inflammatory tunneling tracts around the anus communicating with the rectum, most commonly seen in German Shepherds.