Pattern Alopecia in a Miniature Pinscher Dog

In 2011, a 4-year-old castrated male Miniature Pinscher dog weighing 5.6 kg was examined for diffuse symmetric alopecia on the chest and excessive scaling. The dog presented with alopecia on the neck and thighs, and severe scales, with dermatologic tests indicating bacterial infections. Histopathological analysis showed atrophy of the hair bulb in the affected areas. An ACTH stimulation test revealed abnormally high pre- and post-ACTH serum testosterone levels, but normal estradiol and cortisol levels. Based on the clinical history, physical examination, hormonal assays, and dermatohistopathologic findings, the dog was diagnosed with canine pattern alopecia. Treatment with melatonin for 3 months resulted in improved alopecia on the trunk and general hair regrowth.