Demodex mange: This is a skin disease of young dogs. It is not contagious to humans. Puppies contract this disease while nursing from their mother. It will usually stay dormant in the pups until the teething period begins at about 4 months of age or a time of stress such as a bitches first time in heat. At this time, the microscopic mites begin to multiply and eat hair follicles resulting in visual hair loss. The hair loss is usually patchy and can be anywhere on the body, but most commonly starts on the head. Any patchy hair loss on your puppy should be seen by your veterinarian so a diagnostic skin scraping can be done. The mites are easily visualized under the microscope. Treatment consists of weekly dippings of the body with a product such as Mitaban and or the use of Ivomec.Daily application of medicine to the spots may relieve discomfort. This treatment is continued until a negative skin scraping is achieved. Once the mites are all killed they usually never recur. Researchers believe that many puppies and adult dogs have demodex in a symbiotic relationship, which means there are no outward lesions. It is believed that the stress of teething and some immune deficiency may cause it to become a clinical problem in some puppies or young dogs.