Peter Kintze, DVM, DACVIM

Trilostane, currently the most used treatment for PDH, is a synthetic steroid analogue. It competitively inhibits the 3-beta hydroxysteroid dehydrogenase enzyme blocking cortisol, aldosterone and sex hormone production.

Canine hypothyroidism is one of the more common endocrine diseases seen by small animal clinicians. As thyroid screening has become more frequently utilized, practitioners have become more aware of the frequency with which hypothyroidism occurs.

There have been several new findings in canine and feline endocrinology. We will highlight those that are useful and applicable to clinical practice. New diagnostic protocols and treatments will be discussed where appropriate.

Insulinomas are tumors that arise from the beta cells of the pancreatic islets and secrete excessive amounts of insulin, resulting in hypo?glycemia. The secretion of insulin is usually episodic, as are the resulting clinical signs. Insulinomas in dogs are typically malignant and almost always metastasize; even those appearing benign on histo?pathological evaluation. Insulinomas are rare in dogs.

Hyperadrenocorticism can be pituitary-dependent (PDH), secondary to cortisol-secreting adrenocortical neoplasia, or iatrogenic. Spontaneous hyperadrenocorticism is primarily a disease of middle-aged to older dogs.

Feline hyperthyroidism is the most common endocrine disorder of older cats. Thyroid hormone excess effects multiple organ systems and the associated clinical signs range in severity from mild to severe and are quite variable from cat to cat. As a result of the increased incidence of the disease, the increased index of suspicion among practicing veterinarians and the increased screening of geriatric cats for hyperthyroidism, the average hyperthyroid cat is now evaluated earlier in the course of disease than when the disorder was first recognized.