Dr. Bruyette welcomes endocrinology questions from veterinarians and veterinary technicians.
Click here to submit your question, or send an e-mail to vm@advanstar.com
with the subject line "Endocrinology questions."
Q. Yesterday, I saw a 7-year-old neutered male obese (112-lb) Labrador retriever for evaluation of lethargy, partial anorexia,
weight loss (10 lb in three months), and heavy panting. The owner thinks the dog is drinking more water. Abnormal CBC results
include moderate erythrocytosis, lymphopenia, and eosinopenia. The serum alkaline phosphatase activity is 395 mU/ml, and the
glucose concentration is 310 mg/dl. The dog has glucosuria (4+) and a urine specific gravity of 1.014. The urine cortisol:creatinine
ratio is 2.96. Do I continue screening for hyperadrenocorticism, or should I treat for diabetes while attempting to gradually
reduce this dog's weight?
 David S. Bruyette, DVM, DACVIM VCA
|
A. This is a great question and common clinical problem. In general, we try to regulate the diabetes before attempting to diagnose
hyperadrenocorticism. Although this dog's UCCR result is normal, diabetes mellitus and many other nonadrenal illnesses can
affect the pituitary-adrenal axis, resulting in false positive results on the UCCR, ACTH stimulation test, and the low-dose
dexamethasone suppression test. I would treat the diabetes first and, once you think you have adequate glycemic control, then
revisit whether the dog may have concurrent hyperadrenocorticism. If you think there is an indication to evaluate the pituitary-adrenal
axis, I would start with the ACTH stimulation test, as it appears to be less affected by concurrent disease.
David S. Bruyette, DVM, DACVIM VCA
West Los Angeles Animal Hospital
1818 S. Sepulveda Blvd.
West Los Angeles,
CA 90025
Veterinary Diagnostic Investigation and Consultation
26205 Fairside Road
Malibu, CA 90256