Demodectic Mange in Cats

Demodectic mange is a skin disease that affects both cats and dogs. In cats, it is commonly known as feline scabies. Demodectic mange in cats is caused by a different species of mite from the Demodex canis mite that causes demodectic mange in dogs. Its symptoms and treatment are also different.

Causes of Demodectic Mange in Cats

There are two types of mites that cause demodectic mange in cats; they are Demodex cati and D. gatoi. D. cati lives in hair follicles; D. gatoi lives in the outer layer of your cat's skin.

Both of these mites are normally present on all healthy cats. Normally, your cat's immune system keeps the population of these mites in check, so that they don't grow out of control and cause a skin irritation. Sick cats are more likely to suffer from localized infections of demodectic mange; cats who suffer from immunosuppressant diseases are most likely to develop generalized symptoms of demodectic mange. Burmese and Siamese cats seem especially prone to feline scabies.

Symptoms of Demodectic Mange in Cats

Feline scabies can occur as a localized or as a generalized infection. Localized infections are more common, and can often occur in cats being treated with steroids. Localized infections affect the eyelids, head, ears and neck. Symptoms include:

  • Hair loss on the affected area.
  • Scaly, itchy lesions.
  • Inflammation and irritation.

Generalized infections are usually a result of an underlying medical condition that has compromised your cat's immune system. Symptoms are similar, but can affect the legs and body. Conditions that can compromise your cat's immune system in this manner include:

  • Feline leukemia
  • Feline Immumodeficiency Virus
  • Diabetes

Demodectic mange should not be confused with cheyletiellosis, a skin disease caused by an infestation of Cheyletiella mites, which is characterized by itchy, scaly skin and can affect the entire body, particularly the back. Cheyletiellosis is known as "walking dandruff" because, upon close inspection, the scales appear to be moving. This movement occurs when mites walk around under the scales. Cheyletiellosis, unlike demodectic mange, is contagious to both humans and dogs.

Diagnoses and Treatment of Demodectic Mange

Your vet can make a diagnosis of demodectic mange by taking a scraping from the affected area and examining it under a microscope. Once your vet has identified the type of mite involved, one of many treatment options can be used.

For localized infections, a topical solution of rotenone or amitraz may be used. Lime sulfur dips can also be applied. The oral drug ivermectin can also be effective in the treatment of localized demodectic mange. Treatment of demodectic mange should occur under close veterinary supervision.

In the case of a generalized infection, your cat should be screened for underlying medical conditions. In most cases, treatment of the underlying condition will cause demodectic mange lesions to heal on their own as your cat's immune system gains strength. Sometimes, lesions may become infected. These secondary infections should be treated with antibiotics.

Demodectic mange is rare in cats but very contagious (although not to humans). If you have multiple cats in your household, make sure they all receive treatment for feline scabies, even if they aren't showing symptoms. Fortunately, demodectic mange is easy to identify and treatment is usually quite successful.