here's an article about mange (both types)
Demodex canis is the scientific name for the mite that causes “demodectic mange”. This follicular mite lives in the hair follicle where it occupies the space between the hair shaft and the lining of the hair follicle.
It is believed to feed on fluids present in the hair follicle. It causes inflammation in the hair follicle. This inflammation damages the hair follicle and the surrounding skin causing the hair to fall out.
As the infestation progresses, secondary bacterial infection occurs which results in formation of pus and drainage from the skin surface. It is believed that all puppies acquire a small number of mites during nursing and dogs normally have a small number of mites in their skin.
The immune system normally keeps the number of mites in check and most dogs never develop disease from the mite. However if the immune system is weakened by disease or medications that are immunosuppressive, the mites may multiply and cause disease.
It is believed that susceptibility to mange can also be inherited. This is the reason some veterinarians do not recommend breeding dogs that have ever gotten demodectic mange.
The most common finding in dogs with this type of mange is hair loss that starts on the face and/or legs. This type of mange does not cause itchiness unless a secondary bacterial infection occurs.
This type of mange is not considered to be contagious to other dogs and isolation from unaffected dogs is not believed to be necessary. This type of mange is not contagious to people.
Diagnosis is by multiple skin scrapings and examination of the material with a microscope. The only approved treatment is MitabanTM (amitraz) a dip that is applied to the skin. For some difficult cases 1% ivermectin, used to treat parasites in cattle and horses, has been used.
This drug is not approved for treatment of demodicosis in dogs and has significant possibly fatal side effects if used improperly. Advice from a veterinarian familiar with your dog is needed.
Sarcoptes scabei causes the second most common type of mange in dogs, “sarcoptic mange” or “scabies”. The canine scabies mite is slightly different than the scabies mite that can be found in nursing homes. There are many important differences
between sarcoptic mange and demodectic mange. Sarcoptes mites do not normally inhabit the skin of dogs. They are acquired by contact with infested dogs or objects that have been in contact with infested dogs.
This mange can also be acquired by contact with infested foxes, raccoons or other wild mammals. Dogs can also get the mite by lying down in the same spot as an infested animal. The mite lives in the epidermis (the upper layer of the skin) not within hair follicles.
Sarcoptic mange always causes itchiness that can be quite severe, even if a secondary bacterial infection is not present. The more commonly affected areas are the head, ears, underside, elbows and feet.. Hair loss occurs because of scratching. The skin is usually inflamed. This mange is also contagious to humans although some people may not be as susceptible as others.
It is important that infested animals are isolated from non-infested animals. Positive diagnosis is by finding mites during microscopic examination of material collected from skin scrapings.
However this type of mite can be hard to find and often treatment is recommended based on physical exam alone. It can be easy to confuse the itchiness of sarcoptic mange with the itchiness of other skin disease such as allergy.
Treatments include amitraz, lime-sulfur dips, and 1% ivermectin. Your veterinarian will usually treat all dogs in contact with the infested dog at the same time.
Bedding should be discarded or washed in hot water. Using the same insecticidal products used for killing fleas in the environment can kill any mites present in the environment.
This type of mange can occur in any dog even if their immune system is functioning normally. There does not appear to be any inheritable susceptibility to this type of mange.
Prevention is by avoiding contact with infested dogs and avoiding contact with areas inhabited by infested wild animals.