Black hair follicular dysplasia in a fox paulistinha dog: clinical and histopathological features

Abstract

Black hair follicular dysplasia (BHFD) is an unusual canine skin disorder defined as alopecia confined to black regions of the hair coat. First clinical abnormalities are usually noted around four weeks of age and comprise fracture of hair shafts in black-coated regions, later resulting in partial alopecia, usually, on the head, ear pinnae, neck, and back, whereas some nonblack-coated areas may exhibit normal hair. The diagnosis is confirmed by histopathologic features. This article aims to report a case of black hair follicular dysplasia in a seven-month-old Fox Paulistinha male dog showing alopecia restricted to black-haired areas, in which diagnosis was confirmed by histopathological exams that showed follicular dysplasia associated with melanic accumulation in the hair shaft and in and deep dermal tissue.