Congenital/Hereditary Alopecias

Hereditary alopecias - overview
Congenital alopecia occurs either at birth or within 2-4 weeks of life. Hereditary alopecia can occur at an early age or may have a tardive onset. Alopecia with a late onset may be more difficult to differentiate from endocrinopathies and other acquired alopecias.

Classic examples of hereditary alopecia are the hairless breeds. These dogs and cats have been purpose bred for a lack of a haircoat, but this does represent a hereditary disorder. Recognized breeds are mexican hairless, american hairless terrier, chinese crested dog, peruvian inca orchid and the sphynx cat. In the mexican hairless an autosomal dominant mode of inheritance has been demonstrated and in american hairless terriers it has been shown to be an autosomal recessive trait.

Inherited alopecias have no known specific therapies. Dietary manipulations, bathing and nutritional supplements have been proposed but have not been shown to be effective. Melatonin has been used with some success in some of the acquired, endocrine and hereditary alopecia.

Diagnosis is usually based on clinical signs, signalment and biopsy. Biopsy samples should be taken from affected areas and “normal” areas for comparison.

Since there are no known cures the goal is to obtain an accurate diagnosis and educate the owner on care of the hairless skin. Generally speaking the hairs and sebaceous glands will be miniaturized and therefore the skin will be dry. Comedones may also form and may lead to secondary infections. Good gentle, cleansing, moisturizing and protection from the elements (cold, sun etc) should be recommended. [...]