Demodicosis (Demodectic mange, red mange) is a skin disease caused by a mite, Demodex canis, in the hair follicle. The localized form consists of one or more small areas of hair loss. The lesions are usually on the head or front legs, although any area of the body may be involved. The generalized form is more extensive and is combined with inflammation, scaling and secondary skin infection. Although all breeds are affected, the highest incidence is in Doberman Pinschers.

The development of the disease requires two things--the presence of the mite and a genetic susceptibility (poor immune response) of the dog. Exposure occurs exclusively by transmission from the mother (who may have never shown signs of the disease) during the first few days of life. Dogs with normal immune systems may have mites on their skin but never develop skin disease. Most problems occur in puppies because their immune systems often develop slowly.

Because the immune response of many puppies improves as they mature, the disease will sometimes resolve spontaneously. We cannot rely on this, however, because the presence of the mites themselves tends to suppress immune response, predisposing the puppy to severe secondary skin infection. The older the patient is, the more aggressive the treatment may need to be.

HOW IS IT DIAGNOSED?
Diagnosis is made by scraping the top cell layers of skin lesions, preparing slides for microscopic examination, and demonstrating live mites under the microscope.

HOW IS IT TREATED?
Several treatments are available--topical application of amitraz solution, oral ivermectin or high doses of milbemycin. Medicated shampoos, good nutrition, multiple vitamins and antibiotics may also be used. We will select the treatment plan that best suits your case. Treatment should be continued until negative skin scrapings can be demonstrated.

WHAT IS THE PROGNOSIS?
In dogs with localized demodicosis, 90 percent respond in 3-8 weeks. The prognosis is excellent and there is no limitation on breeding. The generalized form, however, may take much longer to respond and in some cases can require lifelong treatment. These individuals should not be used for breeding. A high percentage of treated individuals recover completely. A few face recurring episodes throughout their lives and extreme cases develop severe, and sometimes fatal, secondary infections.

Demodectic Mange

Back to External Parasites
Back to PetEd