Canine follicular dysplasia
From Wikipedia, the free encyclopedia
Follicular dysplasia is a genetic disease of dogs causing alopecia, or hair loss. It is caused by hair follicles that are misfunctioning due to structural abnormality. There are several types, some affecting only certain breeds. Diagnosis is achieved through a biopsy, and treatment is rarely successful.
Contents |
[edit] Structural follicular dysplasia
Structural follicular dysplasia varies by breed but all involve weakened hairs that break easily. Hair loss is originally seen in areas of repeated grooming or trauma, for instance the neck because of contact with a collar. Hair regrowth may occur, but the hair will be even weaker and the pattern will repeat. The dogs are affected between the ages of two to four years, and it is most commonly seen on the back towards the tail. Progression of the hair loss to cover the trunk can occur.
[edit] Commonly affected breeds
[edit] Atrophic follicular dysplasia / Pattern baldness
In some breeds hair follicles in certain parts of the body become progressively miniaturized, analagous to what occurs in male pattern baldness in humans. Affected areas become progressively more alopecic. The pattern of hairlessness that results is somewhat breed-dependent and sex dependent. In short-coated toy and miniature dogs, ventral neck, ventral chest, ventral abdomen and inner thighs are affected. In males, the pinnae (ear flaps) are affected. In greyhounds, the thighs are affected as well as the ventral chest and abdomen.
[edit] Cyclic follicular dysplasia
Cyclic follicular dysplasia is also known as seasonal alopecia.
It causes bilateral hair loss and hyperpigmentation of the flanks. The disease usually starts in the late fall or early spring, and can regrow in about six months, although the hair may be different in color or texture. Treatment with melatonin may result in hair regrowth sooner, so it is thought that the amount of daylight influences this condition. The dogs are affected between the ages of two to four years.[1]
[edit] Commonly affected breeds
- Airedale Terrier
- English Bulldog
- Staffordshire Terrier
- Wirehaired Pointing Griffon
- Boxer
- Affenpinscher[1]
[edit] Follicular lipidosis
Follicular lipidosis is a type of follicular dysplasia found in the Rottweiler. It usually occurs before the age of nine months and involves loss of some of the mahogany or red hair of the face and feet. It is caused by lipid invasion of the hair follicle cells.
[edit] Color dilution alopecia
Color dilution alopecia is an inherited type of follicular dysplasia. It most commonly affects dogs with blue or fawn coats, which are dilutions of black and brown, respectively. Dilution is caused by irregularities in melanin transfer and storage. Signs of color dilution alopecia include hair loss and recurrent skin infection on the back. It can involve the whole body. The condition starts between the ages of six months and two years. Early hair loss occurs due to hair breakage, making it similar to structural follicular alopecia. It is important to treat the skin infections, and etretinate has been used to treat the hair loss.
[edit] Commonly affected breeds
- Dobermann - has the highest frequency of this condition. It occurs in 93 percent of blues and 75 percent of fawns.[1]
- Dachshund
- Great Dane
- Whippet
- Italian Greyhound
- Chow Chow
- Standard Poodle
- Miniature Pinscher
- Yorkshire Terrier
- Silky Terrier
- Chihuahua
- Boston Terrier
- Saluki
- Newfoundland
- German Shepherd Dog
- Shetland Sheepdog
- Schipperke
- Bernese Mountain Dog
- English Bulldog
[edit] Other types of follicular dysplasia
The Siberian Husky and Alaskan Malamute have a type of follicular dysplasia that occurs between the ages of three and four months, possibly later in the Malamute. The guard hairs of the trunk are progressively lost and the coat turns reddish in color.
In black or red Dobermanns, Miniature Pinschers, and Manchester Terriers there is a type of follicular dysplasia that occurs between the ages of one and four years. It begins in the flank and spreads to the back.[1]
