The long-term outcome, prognosis, and risk factors that affect survival time of ferrets with hyperadrenocorticism following surgical treatment were evaluated in a retrospective study. Information from the medical records included history; primary clinical sign at the time of admission; findings on physical examination, hematologic and serum biochemical analysis, and abdominal ultrasonography as well as information on surgical findings and technique; postoperative complications; and results of histologic evaluation. Domestic ferrets treated surgically for adrenal gland disease had a good prognosis, with 98% and 88% survival rates at 1 and 2 years, respectively, and a 70% survival rate at 5 years. Survival time of ferrets undergoing surgery was not affected by the histologic characteristic of the tumor, the adrenal glands affected (right, left, or both), or complete versus partial adrenal gland resection. Left adrenal glands were more commonly affected than right glands and are more often completely resected because of their location relative to the caudal vena cava. In this study, the addition of cryosurgery with partial resection was a negative prognostic indicator for long-term survival. If larger numbers of patients were evaluated, this finding may not be significant. Although complete tumor resection is the goal of surgical treatment, partial resection seems to be sufficient to achieve long-term survival, especially for tumors involving the right adrenal gland.
COMMENTARY: This report involves cases of surgically treated adrenal gland disease at the University of Colorado over a 9-year period (1995-2004). Although the term used in the title is "outcome," a more correct term might be "long-term survival"-the study evaluates how long the animals that survived surgery lived afterward, not such factors as disease-free interval or quality of life. Animals that died during surgery were excluded from analysis. Some important findings include good long-term survival of the ferrets, with a 98% 1-year survival rate and a 70% 5-year survival rate for animals for which follow-up was available. Another important finding was that tumor type and histologic grade did not affect long-term survival. Although this study does not enable us to compare ferrets treated surgically with those treated medically or left untreated, it does show that surgical treatment can be a good option.
Long-term outcome of domestic ferrets treated surgically for hyperadrenocorticism: 130 cases (1995-2004). Swiderski JK, Seim HB, MacPhail CM, et al. JAVMA 232:1338-1343, 2008.