Black Hair Follicular Dysplasia in Dogs

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. Clinical diagnosis is not usually difficult as it is a visually striking disease.

Signs of Black Hair Follicular Dysplasia

Extensive alopecia develops in the affected dark-hair spots. 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.

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. A genetic defect in melanin transfer and hair shaft formation is suggested to be the cause. 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.

It has been suggested that in the Gordon setter black hair follicular dysplasia might be autoimmune disease.

Testing for Black Hair Follicular Dysplasia

DNA test is available to identify dogs that carry the f allele for black hair follicular dysplasia. The DNA test allows a breeder to control the f allele frequency in predisposed breeds thus preventing the production of puppies affected with BHFD. This DNA test accurately and specifically identifies normal, heterozygotes and affected dogs.

Black hair follicular dysplasia has been reported in the following breeds:

References:
1. Guidelines for Veterinarians: Prevention of Zoonotic Transmission of Ascarids and Hookworms of Dogs and Cats, Centers for Disease Control and Prevention, National Center for Infectious Diseases, Division of Parasitic Diseases