**Demodectic Mange according to the book, Muller & Kirk's Small Animal Dermatology 6th Edition.
Also called demodicosis or Red Mange, demodectic mange in dogs is caused by a sensitivity to and overpopulation of Demodex canis as the animal's immune system is unable to keep the mites in check. This is a mite that occurs naturally in the hair follicles of most dogs in low numbers around the face and other areas of the body. In most dogs, these mites never cause problems. However, in certain situations, such as an under-developed or impaired immune system, intense stress, or malnutrition, the mites can reproduce rapidly, causing symptoms in sensitive dogs that range from mild irritation and hair loss on a small patch of skin to severe and widespread inflammation, secondary infection, and—in rare cases—a life-threatening condition. Small patches of demodicosis often correct themselves over time as the dog's immune system matures, although treatment is usually recommended.
Minor cases of demodectic mange usually do not cause much itching but might cause pustules on the dog's skin, redness, scaling, hair loss, or any combination of these. It most commonly appears first on the face, around the eyes, or at the corners of the mouth, and on the forelimbs and paws.
In the more severe form, hair loss can occur in patches all over the body and might be accompanied by crusting, pain, enlarged lymph nodes, and deep skin infections.
Demodectic mange is not generally contagious to people, other animals, or even other dogs (except from mother to pup). However, the mite is zoonotic, and, upon infesting a human, will generally live in the hair follicles of the eyelashes and eyebrows. These mites thrive only on very specific hosts (dogs) and transmission usually occurs only from the mother to nursing puppies during the first few days after birth. The transmission of these mites from mother to pup is normal (which is why the mites are normal inhabitants of the dog's skin), but some individuals are sensitive to the mites, which can lead to the development of demodectic mange.
[Biggie gets a soothing bath]