Atypical Cushing's Syndrome Associated with Sex Steroids Excess in a Dog

A 10-year-old, intact male, toy poodle was presented with abdominal distension, truncal alopecia, hepatomegaly, and sustained elevation of alkaline phosphatase. Vacuolar hepatopathy and glycogen deposition in hepatocytes were confirmed by liver biopsy and ultrasound-guided fine-needle aspiration with periodic acid-Schiff (PAS) staining of mass lesion respectively. Cortisol and some sex hormones associated with adrenal gland were analyzed at IDEXX Reference Laboratories before and 1 hour after ACTH stimulation. The results of analysis confirmed elevation of some sex hormones including androstenedione, progesterone and 17 hydroxyprogesterone, not cortisol concentration, before and 1 hour after ACTH stimulation. The dog was diagnosed as atypical form of hyperadrenocorticism associated with sex steroids excess. The treatment was initiated with trilostane (0.5 mg/kg, PO, q12hr) that is an adrenal steroid synthesis inhibitor. Trilostane was administered for 8 weeks and the clinical sign including truncal alopecia was improved.