HYPERADRENOCORTICISM IN 6 CATS

The case records of six cats with hyperadrenocorticism presented to th e Department of Clinical Veterinary Medicine, University of Cambridge, over an Ii-year period were reviewed. Signalment and clinical signs w ere similar to previous reports but, in contrast to other reports, onl y three cats had diabetes mellitus on presentation. Abdominal radiogra phs revealed an adrenal mass in one case, obesity in all cases but no hepatomegaly, The adrenal glands were identified ultrasonographically in three out of six cases. Clinicopathological findings were non-speci fic. The diabetic cats had a significantly lower serum potassium conce ntration than the nondiabetic cats (P<0.05). Results of adrenocorticot rophic hormone (ACTH) stimulation tests were supportive of a diagnosis of hyperadrenocorticism in the five cats in which they were performed . Five cats had pituitary-dependent hyperadrenocorticism (PDH) and one had an adrenal tumour. Differentiation between the two forms of hyper adrenocorticism was possible preoperatively in five out of six cats. A drenal histopathology confirmed hyperplasia in four cats and adenocarc inoma in one cat. Three cats with PDH underwent bilateral adrenalectom y and two of these cats had low, flat ACTH stimulation tests postopera tively and survived for significant periods. The cat with an adrenal t umour underwent partial unilateral adrenalectomy, maintained a positiv e ACTH stimulation test postoperatively and was euthanased one week af ter surgery.