Pomeranian black skin disease (alopecia X): signs and care

Your Pomeranian is losing hair in symmetrical patches on the rear body, thighs and tail. The bare skin is slowly darkening toward black. Yet your Pom isn’t itchy and still eats and plays normally. That is most likely Pomeranian black skin disease, known medically as alopecia X. It spoils the coat, but it usually doesn’t hurt the dog. Still, only a veterinarian can name it correctly, and only after ruling out hormonal diseases that look exactly the same.

That thick coat is what owners love most about a Pom. So a thinning coat is scary. The first question is usually whether the dog is seriously ill, followed by what to do about it in Vietnam, where the heat and humidity last all year.

What does Pomeranian black skin disease look like?

The early stage is easy to miss because the disease moves slowly. First, the coat on the body turns dry and dull and loses its shine. Then the guard hairs (the long, coarse outer layer) gradually fall out. Only the soft undercoat remains, so your Pom looks like it has its puppy coat back.

According to veterinary dermatologists interviewed by the American Kennel Club (AKC), hair loss usually starts on the rear part of the body and spreads, matching on both sides. The head and lower legs usually keep their hair. The tail varies. Some Poms keep a fluffy tail, while others lose all of it and end up with a “rat tail.” Skin that stays exposed for a long time turns dark, which is why owners call it black skin disease.

Alopecia X itself does not cause itching. However, bare skin has lost its protective cover, so it is prone to irritation or secondary infection. When that happens, you may see scaling, greasy skin, dandruff or small pimples.

Why do Pomeranians get alopecia X so often?

Nobody knows exactly. The “X” in the name means the cause is unknown. What is certain is that the condition is tied to thick, double-coated Spitz breeds from cold climates, such as the Chow Chow, Samoyed, Husky, Alaskan Malamute and Keeshond. The Pomeranian is the breed affected most often.

Vets also call it hair cycle arrest. The hair follicles stay in the resting phase for too long. Old hair falls out, and new hair doesn’t grow in.

Veterinary dermatology material from the University of Minnesota says the disease is most common in young males around 1–3 years old. Females and spayed or neutered dogs can still get it. A study of Poms in the Netherlands and Belgium found two associated factors: a woolly coat (a heavy, soft, fluffy undercoat) and being male.

On genetics, sources disagree. The AKC classifies alopecia X as an acquired condition, yet the way it clusters in a few breeds points to an inherited predisposition. That’s why nobody, breeders included, can promise that a Pom puppy will never develop it.

Is it safe to shave a Pom to keep it cool?

No, and in Vietnam this is the most common way it goes wrong. When the weather turns hot, many families take their Pom to a pet spa for a close shave. Then they wait and wait for the hair to grow back.

This is called post-clipping alopecia. It is another form of hair cycle arrest, and it’s common in double-coated breeds like the Pom. According to University of Minnesota material, hair usually grows back within about 3–4 months after clipping. If it hasn’t returned by then, something is off, and some dogs take 12–24 months to regrow a full coat. Others regrow only the undercoat while the guard hairs never come back, leaving the coat patchy and different in texture from before.

We don’t recommend shaving a Pom down to the skin to beat the heat. The double coat shields the skin from the sun. Shave it off and the skin is exposed directly to harsh sunlight. To help your Pom stay cool, brush out dead undercoat regularly and keep trims neat without clipping close to the skin. During the hottest hours, keep your dog in a well-ventilated or air-conditioned room.

What kind of hair loss means your Pom needs a vet?

If your Pom is losing hair in patches, see a vet. Alopecia X is only diagnosed after other causes have been ruled out. No single test confirms it. Vets usually run blood work, check thyroid and adrenal hormones and sometimes take a skin biopsy.

The conditions most easily confused with it are hormonal diseases such as Cushing’s disease (the adrenal glands produce too much cortisol) and hypothyroidism. Parasites, fungal infections, skin infections and allergies also cause hair loss. If the hair loss comes with any of the signs below, take your Pom to a veterinary clinic soon. Don’t wait to see whether the hair grows back on its own:

• Drinking and urinating much more than usual.
• Eating far more than normal or refusing food, with obvious weight gain or loss.
• Heavy panting even when it isn’t hot, sluggishness or little interest in play.
• Red or itchy skin, constant scratching, a bad smell or sores.

One cause people rarely consider is human medication. The AKC quotes a veterinary dermatologist who is seeing many cases of hair cycle arrest in dogs exposed to estrogen-containing drugs or strong topical steroids. If anyone in your home uses these, keep them out of your Pom’s reach. Don’t let your dog lick freshly treated skin.

Don’t confuse this with a Pom puppy shedding its puppy coat. During that stage the puppy looks scruffy for a while before the adult coat comes in. The hair falls out evenly all over the body instead of leaving symmetrical bare patches. The skin doesn’t darken.

Can alopecia X be treated?

Some dogs regrow their hair and some don’t. Because the condition is benign and usually doesn’t bother the dog, many Poms need no treatment at all. Talk it over with your veterinarian before you decide, ideally one with dermatology experience.

Options a vet may consider include neutering males, hormone therapy, melatonin, microneedling and platelet-rich plasma injections. According to the AKC, melatonin works well in about 30–40% of cases and is not used in dogs with diabetes. Microneedling is painful. Dogs usually need sedation or anesthesia for it. University of Minnesota material notes that hair may regrow after neutering, though the hair loss often returns after 1–2 years.

Never give your Pom melatonin or human supplements on your own. Whether your dog can take them, and in what form, is for your veterinarian to decide after an exam.

How do you care for bare skin in hot, humid weather?

The main job is keeping bare skin free of infection and sunburn. The dermatologist in the AKC article recommends regular baths with a gentle dog shampoo that is pH-balanced and moisturizing. Use a product made for dogs.

In Ho Chi Minh City (Saigon), where humidity stays high all year, drying matters as much as bathing. After every bath, dry the undercoat to the skin. Damp, half-dry fur that traps moisture is where fungi and bacteria thrive on already weakened skin.

Bare skin is easily damaged by the sun, especially light patches that haven’t darkened yet. Keep your Pom out of the midday sun and away from windows where sunlight pours in. Outdoors, a thin UV-protective dog shirt helps.

For diet, feed good-quality kibble in the amount you’ve been advised. If you want to add fatty acids such as fish oil, ask your veterinarian first.

A Pom’s coat depends on both genetics and care. That makes the parents the most reliable guide to how a puppy’s coat may turn out. If you’d like to see the parents, their coats and the paperwork for our Pom puppies, chat with us on WhatsApp. If you’re ever in Ho Chi Minh City, message us to book a time before stopping by 52 Le Lai Street, Bay Hien Ward.

Medical information in this article was reviewed by veterinarians at Home Pet Veterinary Clinic on October 13, 2026.