Alopecia X in Dogs | Black Skin Disease in Dogs

By Caitlin Ultimo

If your dog has been losing patches of his hair or fur and you’ve noticed dark skin grow back in its place you may be wondering: What’s causing this to happen? You may also be worried and want to determine if this is a sign of something bigger or if it is causing your pet any discomfort. If this is the case for your pet, you’ll want to talk to your vet as his symptoms could be a sign of an endocrine condition called Alopecia X. Here’s what you should know:

What is Alopecia X?

Alopecia X is also known as Black Skin Disease, Adult Onset Growth Hormone Deficiency, Growth Hormone-Responsive Alopecia, Castration-Responsive Alopecia, and more recently, Adrenal Hyperplasia-Like Syndrome.  It is an uncommon, cosmetic skin condition with characteristic areas of hair loss (alopecia) and hyperpigmentation (dark or “black” skin). “This syndrome is recognized in both male and female dogs as an adrenal imbalance of the sex hormones (estrogen or testosterone), in combination with depleted production of melatonin,” explains Dr. Mark Macina, staff doctor if dermatology at NYC’s Animal Medical Center. “Low melatonin levels stimulate pigment cells, making the skin appear to darken over time, while the hormonal imbalance contributes to an arrested growth phase in the hair follicle, causing hair loss and/or the inability to regrow the coat.” Some breeds that are predisposed to the congenital or inherited defect include Pomeranians, Chow Chows, Siberian Huskies, Keeshonds, Samoyeds and Miniature Poodles.

Signs and Symptoms of Alopecia X in Dogs

“Hair loss can first occur as early as 1 year of age or as late as 10 years of age,” says Dr. Susan Konecny, RN, DVM and medical director at Best Friends Animal Society . “The main clinical sign is the symmetrical and gradual loss of hair over the trunk and back of the thighs, sparing the head and front legs.”

Sometimes the condition may start with your dog losing hair and having a soft “puppy” coat and then the skin may become intensely darker or “hyperpigmented” in the areas that lost hair or fur.

The condition can occur regardless whether they are spayed or neutered, although if the pet is intact, spaying or neutering is highly recommended. “Some dogs may re-grow some hair after they are spayed or neutered, because of the hormonal changes associated with those procedures, although hair re-growth is not always permanent,” says Konecny.

There are no signs of systemic illness associated with this Alopecia X. “If your dog is not eating and drinking (or is eating and drinking excessively), is depressed, acting ill, or has elevated liver or kidney values, then it is important to look for another cause of the hair loss,” says Konecny, as these same symptoms can be recognized in a number of other endocrine system disorders including Cushing’s Disease and hypothyroidism. “It’s best to have your veterinarian run a full blood and chemical screen, including the appropriate endocrine testing to rule these alternative conditions out,” shares Macina.

Treatment Options for Alopecia X

“Treatment for Alopecia X is often a trial and error approach, since the underlying cause of this disorder is not known,” shares Konecny. And while there are ways to help encourage hair growth, because this is a cosmetic condition and the health of the affected pet is not impaired, foregoing treatment entirely is a reasonable option too. Still, there some options for pet parents who want to address the cosmetic symptoms.

The first strategy is to focus solely on the hair follicle itself. “Your vet can correct the lining, decrease plugging, and stimulate growth of the hair follicle while normalizing the maturation of the skin with oral retinoid therapy (related to vitamin A),” explains Dr. Macina. “This should be combined with a melatonin supplement to normalize the appearance of the skin at the same time.” Additionally, a topical glycolic shampoo can also be used to help exfoliate the skin and stimulate hair growth.

“The second option is to focus on the hyper-production or imbalance of the adrenal sex hormones,” says Macina. “Adrenal suppressing medications (similar to those used to manage Cushing’s Disease) can be used, but at lower doses and different frequencies.” While you may see results, this option requires frequent visits to your vet’s office, as regular testing is needed to monitor the medication’s effect on liver function and hormone balance.

“Hopefully through research we will gain a better understanding of the cause of the hair loss and develop a truly effective treatment,” says Konecny.

Image: Jaromir Chalabala via Shutterstock