Diseases Which Cause a Black Skin Rash in Dogs

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Identifying the diseases that cause a black skin rash in dogs is related to the type of '"black rash" appearing on the skin, the area it is in and the symptoms of the canine. Some diseases and conditions cause a rash that looks like black specks on the skin surface or in the fur.

Others appear as eruptions with black crusty skin, or hyperpigmentation, which is a darkening of the skin.


Black specks that look like a rash around the genitals, groin, belly and legs of a dog are the most common symptom of canine flea allergies. The specks are flea "dirt," which are the remains of flea faeces, dried blood and new eggs. As the larvae hatches, they become parasites that eat the dirt for food. Not only is the black rash a breeding ground for fleas, but dogs can also be allergic to flea bites, as a reaction to insect saliva. Itching, red bumps, hair loss and dry skin, mostly around the rump and rear hind quarter of the animal are systemic along with the black rash.

Several prevention methods exist. Fipronil, methodprene or imodocloprid, permethrin are commonly known monthly treatments that veterinarians recommend. Flea and tick collars, topical oils or gels, sprays, shampoos and powders are advisable. These canine flea and dog tick deterrents eliminate black rash flea dirt, and parasite bites, that cause allergic reactions, infections and potential Bartonella, an infection spread by fleas.

Canine Black Crusty Skin

Canine black crusty skin dog disorder can also cause dark skin in dogs. General aspects are darkening of the skin and severe hair loss. Often abnormally low levels of growth hormone are the root cause. Veterinarians will examine the pet's skin with a "wood light," as well do blood tests to check for bacterial and fungal infections, or hormonal levels for specific diagnosis.

Bathing regularly with medicated shampoo are important for bacterial infections, and you can deter yeast infections with anti-fungal shampoos

Canine Black Skin Disease

Canine black skin disease may be misdiagnosed as Cushing's syndrome. A veterinarian is needed to properly diagnose this condition. Some of the contributing factors are hormone imbalance, genetics and allergies. Some breeds are more susceptible to the condition and it may be inherited. As in black crusty skin condition, black skin disease is the primarily evidenced by blackening skin pigmentation.

When the canine is diagnosed with black skin disease due to a sex hormonal problem, vets usually recommend neutering. Otherwise treatments may include prescription medications or natural remedies. Hormonal, breed considerations and inherited dark pigmentation are more cosmetic issues.


All these conditions include either a black rash or pigmentation changes. Regular check-ups, vaccinations and preventive treatments are prudent. When skin, coat, eating, weight loss, lethargy, hyperactivity or other noticeable changes occur, get immediate attention for your dog.