Demodicosis in Dogs
Mange (demodicosis) is an inflammatory disease in dogs caused by various types of the
Demodex
mite. When the number of mites inhabiting the hair follicles and skin
of the dog become exorbitant, it can lead to skin lesions, genetic
disorders, problems with the immune system and hair loss (alopecia). The severity of symptoms depends upon the type of mite inhabiting the dog.
The condition or disease described in this medical article can affect
both dogs and cats. If you would like to learn more about how this
disease affects cats, please visit this page in the petMD health library. You can also learn more about the other common type of mange: sarcoptic mange 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.
Diagnosis
Skin scrapings are used to find and diagnose demodicosis in dogs.
Plucking hairs may also help identify the mite responsible for the
condition.
If performed, a urine test will identify other possible diagnoses,
namely those caused by a disorder with the dog’s metabolic system.
Alternative diagnoses may include bacterial infection in the hair
follicle.
Treatment
If localized, the problem is likely to resolve itself and disappear
spontaneously, which happens in approximately 90 percent of cases. For
severe generalized cases, long-term medication may be necessary to
control the condition. Lime-sulfur dips to the affected areas may help
relieve symptoms. In either case, the general health status of the
animal should be evaluated.
Living and Management
Follow-up care should include skin scrapings, known as trichograms,
to continually monitor the presence of mites and check the treatment’s
progress. With chronic long-term cases, regular medication may be
necessary.
Prevention
General good health may help prevent some cases. It also advised that
dogs with generalized chronic mange not be bred, as the condition is
likely to be passed to offspring.