There are several reasons why the fur may be thin. It is common to see squirrels with patches of fur missing. Hair loss in squirrels can be caused by mange or fungal disease. Mange is a disease caused by microscopic mites that burrow under the skin. The squirrel mange mite (Notoedres sp.) has been reported in both fox and gray squirrels. There have been no reports of this type of mange being transmitted to humans or domestic pets. Loss of hair, and dark, thickened skin are symptoms of mange in squirrels. Mange can be spread by direct contact between squirrels. Adult squirrels in good condition typically survive mild infestations, but severe infestations can be fatal. Additionally, infected squirrels with a lot of hair loss may die of exposure during the winter in areas that experience prolonged periods of cold temperatures. Another possible cause of hair loss in squirrels is fungal disease. A variety of fungal diseases affect squirrels. The fur of infected squirrels will break off at the skin leaving patches of skin that appear to be bare. Otherwise healthy squirrels typically recover from fungal infections.
