Ketoconazole-induced transient hypoadrenocorticism in a dog

A 6-year-old, spayed female, mixed breed boxer dog was presented for decreased appetite, polyuria and polydipsia, and lethargy 9 days after treatment with ketoconazole for Malassezia pododermatitis. Ketoconazoleinduced hypoadrenocorticism was confirmed with an adrenocorticotropic hormone (ACTH) stimulation test, and ketoconazole was discontinued. Clinical signs resolved 48 hours after initiation of prednisone, and resolution of glucocorticoid insufficiency was confirmed with a repeat ACTH stimulation test 48 hours after a 10-day course of prednisone. Glucocorticoid insufficiency after administration of a commonly used dermatological dose of ketoconazole has not been previously reported in veterinary medicine but should be considered in patients with adverse effects while receiving ketoconazole. Key clinical message: Iatrogenic hypoadrenocorticism may occur in dogs treated with commonly used dermatological doses of ketoconazole. The disease is likely transient, but steroid supplementation may be required in some patients to resolve clinical signs, especially in the presence of concurrent illness or stress.