Demodicosis, or demodectic mange, is a fairly common skin condition in puppies. It's caused by a mite that is usually present on all dogs. For unknown reasons, in some dogs, especially puppies, the mite population grows beyond normal numbers and begins to damage the hair follicles in which the mites live. Affected puppies develop bald spots, often on the face, but they may have extensive areas of hair loss often covering the face, forelegs and feet. Many puppies with localized spots get better without treatment; those with generalized involvement (bald spots covering multiple areas of the body) may need dips or systemic medication to resolve the problem. Your veterinarian can diagnose the condition with a skin scraping and can suggest the best treatment.