Color dilution alopecia (CDA) is a genetic condition that strikes dogs with dilute fur colors—these are soft colors, such as bluish or silvery gray, fawn, and cream. It leads to patchy hair loss which eventually can spread over the dog's entire body. Although blue Dobermans are the most commonly affected dogs, any breed with dilute coloring can develop CDA. This condition can be alarming to dog owners who don't understand the disease, but it does not affect the dog's overall health or shorten its life. Unfortunately, however, there is no cure for color dilution alopecia.
What Is Color Dilution Alopecia?
Color dilution alopecia or CDA is an inherited type of hair loss that affects dogs that have a dilute fur color. Blue (silvery or bluish-gray) and fawn (soft brown) are the two most common dilute fur colors in dogs. Many different breeds can sport these fur colors. Also known as color mutant alopecia or blue Doberman syndrome, this inherited disease is a result of a recessive gene that causes hair shafts to break off at the base, along with overall stunted hair growth.
CDA is not fully understood, but it is known that hair follicle damage occurs in dogs with this condition due to melanin clumping in the hair shafts. Typically, puppies carrying the inherited trait have normal coats for their first few months but begin to lose patches of hair as they enter late puppyhood or early adulthood.
Although CDA does not cause skin inflammation or irritation directly, occasionally, bits of broken hair and skin cells can block the hair follicles, leading to secondary bacterial infections that cause itchy or flaky skin. Typically, however, dogs with this condition have normal skin.
Symptoms of Color Dilution Alopecia in Dogs
The defining symptom of CDA is patchy hair loss that usually begins when the dog is still a puppy. Over time, the patches of hair loss grow bigger and eventually the dog can lose all of its fur.
Dilute-colored dogs that have inherited color dilution alopecia may develop symptoms as young as 6 months of age. The coat usually begins to thin and takes on a dull or dry appearance. Fur might fall out in patches or clumps creating a patchy or moth-eaten appearance to the coat, as well. In some dogs, the hair follicles develop bacterial infections around them which results in papules or small bumps on the skin, along with inflammation, itching, and even some flaking.
Causes of Color Dilution Alopecia
Recessive genes that disrupt the way melanin distributes in the hair shafts of dogs with dilute coloring are the cause of color dilution alopecia. The melanin in these dogs tends to clump, leading to fragile hair that breaks off at its base. Affected dogs also have overall stunted hair growth.
In dilute-colored dogs, the recessive gene "dd" is inherited from a parent. Breeding two dogs with this gene results in the potential for their puppies to have the condition. It is important to remember that color dilution alopecia is not contagious or a result of a hormonal imbalance, parasites, or other issue, but rather is always an inherited condition.
Diagnosing Color Dilution Alopecia
If your dilute-colored puppy begins to lose its hair, your veterinarian will first carry out a full physical examination. The vet will perform tests to rule out other issues such as fleas, demodex mites, hypothyroidism, and ringworm that can also cause hair loss. They will usually look at the hair under a microscope to check for abnormal melanin clumps. Occasionally, a skin biopsy is also performed. If damaged hair follicles, abnormal hair shafts, and clumps of melanin are found, then a diagnosis of color dilution alopecia can be made.
Color dilution alopecia is not curable, but luckily it can be managed so that a dog diagnosed with this condition can lead a normal, happy life. Skin infections may occur repeatedly in dogs with color dilution alopecia if measures are not taken to help improve the skin and hair health. Because of this, antibiotics and anti-inflammatory medications may be used temporarily to treat an infection, but long-term management of CDA involves supplements and topical therapies to improve skin and coat health.
Medicated shampoos, sprays, and mousses can be used to moisturize the skin and coat. It's also important to avoid harsh, damaging brushes when grooming dogs with color dilution alopecia. If you get your dog groomed professionally, you will want to tell your groomer about your dog's special needs.
Oral therapies prescribed by your veterinarian may involve melanin, synthetic retinoids such as isotretinoin (Accutane) and etretinate (Tegison), omega-3 fatty acids from fish oils, vitamin A, high-quality diets, and other skin and coat supplements. These supplements help keep the skin and coat as conditioned and healthy as possible. However, hair loss is normally permanent in this condition.
Prognosis for Dogs With Color Dilution Alopecia
While potentially unsightly, color dilution alopecia does not shorten a dog's life or increase its susceptibility to other health conditions. Your dog can lead a normal, healthy, and happy life with this genetic condition.
How to Prevent Color Dilution Alopecia
Because CDA is an inherited condition, the only prevention is to refrain from breeding dogs that carry the recessive gene. Several breeds of dogs that come in blue, silver, or fawn colors have been shown to have the recessive gene for color dilution alopecia more often than other dogs. These breeds include:
- Doberman pinschers
- Miniature pinschers
- Chow chows
- Great Danes
- Irish setters
- Italian greyhounds
- Standard poodles
- Yorkshire terriers
- Bernese mountain dogs
- Shetland sheepdogs
- Boston terriers
Blue Doberman pinschers tend to develop the most severe symptoms so this condition is often associated with that breed.