Mange is a skin disease caused by parasites. If your dog gets mange, she'll be very itchy and may develop some bald patches in her fur. Time for a trip to the vet.
Mammals are vulnerable to mange, which they get when tiny mites embed themselves in their skin. While humans and plants can also be infected by mites, the resulting conditions have different names, including scabies in the case of people. Mange is generally only used for furry mammals including dogs, cats, horses, coyotes, and sheep. If an animal has mange, you can describe it as being (literally) mangy.