Surgical treatment and long-term outcome of ferrets with bilateral adrenal tumors or adrenal hyperplasia: 56 cases (1994-1997).

OBJECTIVE: To determine signalment, clinical signs, concurrent diseases, response to surgical treatment, and long-term outcome of ferrets with bilateral adrenal tumors or adrenal hyperplasia. DESIGN: Retrospective study. ANIMALS: 56 ferrets with bilateral adrenal tumors or adrenal hyperplasia confirmed histologically following subtotal bilateral adrenalectomy. PROCEDURE: Medical records of all ferrets with bilateral adrenal tumors or hyperplasia examined between 1994 and 1997 were reviewed. Ferrets underwent a subtotal bilateral adrenalectomy or a unilateral adrenalectomy initially, followed by a unilateral subtotal adrenalectomy when tumors or hyperplasia later developed on the contralateral adrenal gland. A long-term follow-up of a minimum of 18 months after final adrenal gland surgery was obtained by examination of medical records and follow-up telephone conversations. RESULTS: Clinical signs of hyperadrenocorticism included bilaterally symmetric alopecia, return to male sexual behavior in castrated male ferrets, or swollen vulva in spayed female ferrets. Surgical treatment of bilateral adrenal disease by subtotal bilateral adrenalectomy (or unilateral adrenalectomy followed by contralateral unilateral subtotal adrenalectomy) was effective with a mortality rate of < 2%. Only 3 (5%) ferrets required glucocorticoid or mineralocorticoid replacement following subtotal bilateral adrenalectomy. Recurrence after bilateral adrenalectomy was 15% with a mean long-term follow-up period of 30 months. CONCLUSIONS AND CLINICAL RELEVANCE: Bilaterally symmetric alopecia, return to male sexual behavior in castrated male ferrets, or swollen vulva in spayed female ferrets are indicative of adrenal tumors or adrenal hyperplasia in ferrets. Surgical treatment of bilateral adrenal disease by subtotal bilateral adrenalectomy is effective, with a low rate of complications and postoperative recurrence rate.