Black hair follicular dysplasia (BHFD) is a rare canine hereditary skin disease characterized by lesions that are restricted to the dark hair areas of light colored dogs with darker spots leading to dull, dry, lusterless hair, hair fracture, hypotrichosis and scaliness. A genetic defect in melanin transfer and hair shaft formation is suggested to be the cause. Extensive alopecia develops in the affected dark-hair spots, while adjacent light-hair areas are normal. Darker hair areas often appear washed out, gray or bluish before hair is lost. The bold areas become dry and scaly. Secondary pyoderma is common in the bold areas.
It has been speculated that BHFD and color dilution alopecia are the same entity, as both share histological findings and because some dogs with BHFD are born with gray and white rather than black and white coats. The early age of onset in BHFD, however, differentiates the disease clinically.1 Black hair follicular dysplasia has been reported in the Basset Hound, Bearded Collie, Dachshund, Gordon setter, bi-colored and tri-colored crossbreeds, Jack Russell Terrier, Papillon, Pointer, Large Münsterländer, and Saluki. It has been suggested that in the Gordon Setter black hair follicular dysplasia might be an autoimmune disease.
Clinical diagnosis is not usually difficult as it is a visually striking disease. Puppies appear normal at birth, but by 1 month of age begin losing black hairs only, progressing until all of these hairs are lost by 8-9 months of age. Black haired areas of the head and neck are less severely affected. In black and red Doberman Pinschers, hair loss develops between 1 and 4 years of age, as in the Gordon Setter, and hair loss is dorsally distributed on the lower back. DNA test is available to identify carrier dogs that allows accurately identify normal, heterozygotes, and affected dogs.
Black hair follicular dysplasia has been reported in the Jack Russell terrier breed.
- Black hair follicular dysplasia in Large Münsterländer dogs: clinical, histological and ultrastructural features
- Antinuclear Antibodies (ANA) in Gordon Setters with Symmetrical Lupoid Onychodystrophy and Black Hair Follicular Dysplasia