Pattern alopecia in a miniature pinscher dog

A dog (5.6 kg, 4-year-old, castrated male, Miniature pinscher) with diffuse symmetric alopecia on the chest and excessive scales was referred to Veterinary Medical Teaching Hospital of Chungnam National University, Korea. On physical examination, diffuse alopecia on ventral aspect of the neck and caudomedial thighs, and severe scales were presented. Dermatologic tests of lesions revealed bacterial infections. Histopathologically, atrophy of hair bulb was observed in the severely alopecic lesion of caudomedial thighs. ACTH stimulation test was performed to differentiate the endocrine disorder related to generalized alopecia. The pre-ACTH serum testosterone and progesterone concentrations were above normal ranges and the post-ACTH serum testosterone concentration was high. The pre- and post-ACTH serum estradiol and cortisol concentrations were within normal ranges. Canine pattern alopecia was diagnosed based on history, physical examination, hormonal assay and dermatohistopathologic examination. After 3 months of melatonin administration, multifocal alopecia on the trunk was improved and general hair regrowth was identified.