Demodectic mange is caused by a microscopic Demodex mite. All dogs have demodex mites on their skin that live within the hair follicles. Most dogs live in harmony with their mites, never suffering any consequences from being parasitized. However, if the dog’s immune system becomes suppressed (or in young puppies), the Demodex mites proliferate and can cause serious skin disease. It can occur in isolated spots or affect larger areas and multiple spots on the body.
Demodex mites are host specific, therefore are not contagious to other species. Canine demodex is typically not contagious to other dogs unless infected dog is in contact with immune suppressed or very young/old dogs.
Because demodex live within the hair follicles a deep skin scraping is needed to make this diagnosis. In adult dogs with spontaneous demodex infection, further diagnostics may be warranted to determine the cause of immune suppression to result in this type of infection.
Localized demodex (those cases of demodex that only occur in few small locations on the body) in young dogs do not always require treatment. Depending on the severity of the case topical (medicated shampoos and ointments) and or oral medications (ivermectin) are used. Occasionally, dogs with demodex have secondary skin infections which require oral antibiotics.