Demodicosis In Dogs

Symptoms and Types: Demodectic mange may either be localized and affect specific areas of the body, or generalized, where it affects the entire body. If localized, symptoms are usually mild, with lesions occurring in patches, especially on the face, trunk, or legs. If generalized, symptoms will be more widespread and appear across the body. These symptoms include alopecia, a redness of the skin (erythema), and the appearance of scales and lesions.

Causes: While an exact cause of mange in dogs is unknown, many experts believe genetic factors, such as problems with the immune system, may predispose a dog to developing mange. Three species of mites have been identified to cause mange in dogs. While the mode of transmission is unknown for two of these, it is known that one type, Demodex canis, inhabits the skin and hair follicles and may transfer from mother to newborn during nursing.

How is demodectic mange diagnosed in dogs?
Once Demodectic mange is suspected in a dog, it can usually be confirmed by a skin scraping or biopsy, in which case, the mites can be seen with the aid of a microscope. They are too small to be seen with the naked eye. The adults appear as tiny, alligator-like mites. Remember that these mites are present in every dog, so by themselves, they do not constitute a diagnosis of mange. The mite must be coupled with the lesions for a diagnosis of mange to be made. Older dogs diagnosed with demodectic mange should be screened for certain other diseases such as Cushing's disease, hypothyroidism, cancer, and heart-worm disease. Nutritional history and any history of treatment with corticosteroids or other immune-suppressing drugs should be noted.

How is demodectic mange treated?
The localized form is usually treated with topical medication. The generalized form requires more aggressive treatment using special shampoos and dips, along with oral medication. Shampooing with special cleansing shampoos helps to flush out and open the hair follicles prior to dipping. A separate handout is available to describe the dipping process. In some cases, especially dogs with generalized demodectic mange, secondary skin infections complicate the condition, requiring antibiotic therapy. Dogs with skin infections often have very red, inflamed skin. This is the source of the term "red mange."