The diagnosis of follicular dysplasia is made primarily based upon the breed, the dog’s history and the veterinarian’s physical examination of the animal. External parasite infestation, such as that caused by the mites that cause demodectic mange, among others, must be ruled out as a cause of hair loss. Hypothyroidism and hyperadrenocorticism (Cushing’s Disease), as well as other endocrine disorders, must also be ruled out as a cause of a dog’s hair loss. Of course, the veterinarian will take a thorough history from the dog’s owner and will conduct a thorough physical examination. Routine blood work and a urinalysis will typically be normal in a dog that is only affected by follicular dysplasia. Samples of the dog’s hair and its roots down into the hair follicles will probably be taken and submitted to a laboratory for a diagnosis, which is called a dermatohistopathologic evaluation. A biopsy of affected areas is often helpful as well. This involves taking an actual sample of the skin from an area of hair loss and submitting it to a laboratory for examination by a pathologist, to determine the cause of the alopecia.
There are a number of different types of follicular dysplasia – or hair loss – in dogs. The exact cause of the hair loss may never be precisely diagnosed.