Mites, arthropods related to spiders, cause canine mange. Mange comes in five varieties: sarcoptic mange, demodectic mange, ear mites or otodectic mange, walking dandruff and trombiculosis. Of these types of mange, sarcoptic and demodectic mange can be devastating to dogs.
Sarcoptes scabiei mites cause sarcoptic mange, which is highly contagious. Infected animals can spread the mites to your pets through direct contact or through indirect contact, such as with bedding or other items used by the infected animal. The most common symptom is itching and hair loss. In the long term, untreated pets may develop oozing sores and thickening skin. They may experience oily dandruff called seborrhea. These symptoms can cause death if not controlled.
Normally most dogs carry a small number of demodex mange mites on their skin. However, with dogs that suffer from demodicosis have had the demodex mange mites numbers expand dramatically. This type of mange exists in three forms: localized, generalized, and demodectic pododermatitis. Localized mange usually clears itself up, whereas generalized mange can be devastating.
Generalized demodex mange may be caused by an underlying health issue that might be an endocrine problem, a hereditary problem or an immune system compromised by another disease such as cancer. Often the mange leads to secondary bacterial infections. Dogs with this disease can have inflamed paws, inflamed lymph nodes, fever, lethargy and swollen skin, which has pus in it.
Prescription dips and shampoos are one way your veterinarian may combat this disease. Another way is through prescription medications. Your veteriarian may prescribe antibiotics for secondary bacterial infections. Your dog will probably have to have monthly skin scrapings performed to determine whether the treatment is working. Treatments may have to last for several months.
Demodectic pododermatitis is a type of demodectic mange whereby the infection is in the dogs' feet. It is hard to diagnose and harder to treat. Secondary bacterial infections may accompany such an infestation. Often veterinarians must perform deep tissue biopsies to determine the cause of the infection.
Of the mange types, sarcoptic mange is the most treatable. If your veterinarian diagnoses your dog with sarcoptic mange, you will have to treat all your pets for the disease and throw out or thoroughly clean your pets' bedding. The treatment may last for weeks. If treatment starts in time, your pets should not progress to the chronic stages of sarcoptic mange.
The prognosis for demodectic mange isn't necessarily good. It usually appears in conjunction with other health problems and suggests that the immune system is so compromised that the dog can't ward off mites that would be under control in a healthy dog. It isn't considered contagious, as dogs normally have demodex mites on their skin -- just not in numbers large enough to cause problems.