Sarcoptic mange infestation is a highly contagious disease of dogs found worldwide. The mites are fairly host-specific, but animals (including humans) that come in contact with infested dogs can also be affected. The most common symptom is crustiness around the edges of the ears. Even though this infection usually starts on the abdomen or legs, it can spread over the entire body. Other symptoms are skin pustules, hair loss and intense itching.
Notoedric Mange is a rare, highly contagious disease of cats and kittens and is caused by Notoedres cati , which can opportunistically infest other animals, including humans.
Affected cats are extremely itchy and may present with crustiness and hairloss.
Otodectic mange mites (ear mites) are a common cause of otitis externa especially in cats but also in dogs. Clinical signs include head shaking, continual ear scratching, and ear droop. Common appearance of ear mites is the consistency of coffee grounds in the ear canals.
Cheyletiella blakei infests cats, C yasguri infests dogs, and C parasitovorax infests rabbits, although cross-infestations are possible. This disease is very contagious, especially in animal communities. Human infestation is frequent. They live on the surface of the skin, and their entire life cycle (3 wk) is spent on the pet. Another name for this disease is walking dandruff, because if you look close enough you can see it move.
Canine demodicosis is a skin disease of dogs that occurs when large numbers of Demodex canis mites inhabit hair follicles and sebaceous glands. In small numbers, these mites are part of the normal flora of the skin of dogs and cause no clinical disease. The mites are transmitted from mom to puppies during nursing within the first 72 hr after birth. The mites spend their entire life cycle on the dog, and the disease is not considered to be contagious. Immunosuppression (weak immune system), natural or iatrogenic, can precipitate the disease in some cases. Secondary bacterial infections may occur making it harder to treat. 
Feline demodicosis is uncommon. In localized demodicosis, there are one or several areas of hair loss on the head and neck. In generalized disease, hairloss, crusting, and secondary infection of the skin of the whole body are seen. The generalized form has also been associated with other systemic diseases, especially diabetes mellitus. 
