Hyperadrenocorticism in dogs and cats

Hyperadrenocorticism, either pituitary or adrenal dependent, is common in dogs and rare in cats. In dogs it is suspected if clinical signs such as polyuria, polydipsia, polyphagia, and alopecia are present along with increased serum liver enzymes, cholesterol, or triglycerides; in cats it is often associated with diabetes mellitus. Dexamethasone suppression and/or ACTH stimulation test help confirm the diagnosis. Medical treatments for pituitary-dependent hyperadrenocorticism are trilostane in both species and mitotane or ketoconazole in dogs; although less frequently, transsphenoidal hypophysectomy and radiation therapy are considered. For adrenal-dependent hyperadrenocorticism, adrenalectomy is the treatment of choice; for unresectable adrenal tumors, trilostane and mitotane. Treatment quickly improves polyuria, polydipsia, and polyphagia, whereas a longer time is necessary for dermatologic signs and biochemical parameters to resolve. Prognosis of affected dogs and cats is fair and quality of life is good if treatment is adequately provided.