Primary hyperaldosteronism in a domestic ferret with an adrenocortical adenoma

Case Description - A 6-year-old spayed female domestic ferret was evaluated because of lethargy, alopecia, pruritus, and an abdominal mass. Clinical Findings - On initial examination, nonregenerative anaemia, mild azotemia, and a large left adrenal gland mass were identified. However, deterioration of the ferret's general condition prevented excision of the mass, and dyspnoea, weakness, hypertension, and severe hypokaliaemia developed. Plasma aldosterone concentration was >3,329 pmol/L, confirming a provisional diagnosis of hyperaldosteronism. High concentrations of sex hormones were also observed, but baseline cortisol concentration was within reference limits. Treatment and Outcome - Medical treatment included oral administration of spironolactone, potassium gluconate, leuprolide acetate, amlodipine, and benazepril. Inhalation of albuterol proved effective in reducing the dyspnoea. In the following weeks, serum potassium concentration returned to within reference limits and hypertension decreased, but dyspnoea persisted. Two months after initial examination, the ferret became anorectic and was euthanized. Histologic examination revealed a large left adrenal gland adenoma, progressive chronic nephropathy, severe pulmonary oedema, and focal fibrosis in the left ventricle. Immunohistochemical staining of the adrenal gland mass revealed aldosterone within neoplastic adrenocortical cells. Clinical Relevance - Findings suggested that primary hyperaldosteronism should be considered as a possible cause in ferrets with hypokaliaemia, hypertension, and an adrenal gland mass. Early detection of aldosterone-secreting masses might allow for removal of the tumour before irreversible complications occur.