Follicular dysplasia is a condition caused by an abnormality in the canine hair follicle. It typically manifests as hair loss or abnormal hair growth that progresses over an animal's lifetime.
Several types of follicular dysplasia have been identified, all of them presumably genetic in origin. The most well understood of these, black hair follicular dysplasia, appears as hair loss in black-haired dogs or in black-haired patches in black and white colored dogs. This latter form of the disease is known to be inherited as an autosomal recessive trait.
Symptoms and Identification
For black hair follicular dysplasia, symptoms include a progressively worsening, permanent hair loss over black areas of the skin that begins at about four weeks of age. Scaling and flaking of the skin is common, as are secondary infections that can impart an odor to the skin and elicit itching. For other types of follicular dysplasia, the symptoms will differ by breed (see below).
Though the condition can often be diagnosed by breed and symptoms alone, skin biopsy is strongly recommended for definitive diagnosis.
For black hair follicular dysplasia, affected breeds include:
For other affected breeds, the following clinical signs are evident:
Doberman Pinscher: progressive Flank and back alopecia starting at age 1-2
Siberian Husky and Malamute: Hair loss over trunk, post-clipping alopecia and undercoat crimping along with reddish discoloration beginning at age 3-4 months
Airedale Terrier, Boxer, English Bulldog, Staffordshire Terrier: Alopecia beginning at 2 to 4 years of age in a saddle pattern; hair loss may not be permanent but may recur in a cyclical pattern
Portuguese Water Dog, Irish Water Spaniel, Curly-coated Retriever: Starting at 2 to 4 years, progressive back and trunk alopecia
The Chesapeake Bay Retriever, English Springer Spaniel, German Short-haired and Wire-haired Pointer and Rottweiler may also be affected by this disease.
The disease is not treatable. Management of the scaling and secondary infections is usually undertaken via supplements, shampoos, topical applications and topical antimicrobials when necessary.
The cost is usually limited to diagnosis via skin biopsy (which may or may not require a veterinary dermatologist's consultation, thereby raising the price of the diagnosis) and to treatment of secondary symptoms such as skin infections which may mean accrual of costs which, if symptoms are mild to moderate, could reach a monthly sum of $20 to $50.
The mainstay of prevention involves genetic counseling. Affected dogs and their first degree relatives should not be bred.
Scott, D.W., Miller, W.H., Griffin, C.E. 1995. Muller and Kirk's Small Animal Dermatology. pp 773, 780. W.B. Saunders Co., Toronto.