Demodectic Mange, Canine - contd.
Demodex is a type of skin mite that has a head and eight legs extending from a long, tubular body. In the skin of healthy dogs and puppies, the mites can exist in small numbers, but when the dog's immune system is weakened or not functioning normally, the population of mites begin to increase to the point that skin disease begins.
Demodicosis can manifest itself in two forms. The first is a milder form that occurs commonly in young puppies that get the mites from their mother while nursing. The Demodex mite, which will be localized to just a few regions of the puppy's skin, may cause hair loss, mild redness, scaling, and occasional itchiness. However, with time, the puppy's immune system will strengthen so that it resists the mites and prevents them from overgrowing.
Generalized demodicosis may occur in a dog that, as a puppy, had localized demodicosis that never went away, or in a dog that developed localized demodicosis as an adult. This form of the disease can be very serious because it usually means that another disease is causing the dog's immune system to function poorly, allowing the mite to proliferate at an uncontrolled rate. Because the mites burrow deep into the skin, they cause irritation leading to severe inflammatory skin disease. Many times, forms of bacteria that resist antibiotic medications will grow on the skin, causing severe infections that make the illness worse. The diseased skin of a dog with generalized demodicosis is often hairless, reddened, scaling and, in certain areas, will ooze a pus-filled, bloody material that forms thick crusts. When severe infection occurs, an owner may elect euthanasia for the affected dog because of the poor quality of life.
