Ringworm isn’t actually caused by a worm, but by a fungus. The infection most commonly occurs on the skin, but it could also affect the hair and nails. Ringworm infection is very contagious and could be passed on to other animals, and even humans.
In dogs, ringworm infection usually shows up as hairless patches on the affected area of the skin. Veterinarians typically prescribe shampoos or ointments that will eliminate the fungus, although some may prescribe oral medication. Owners should keep their dogs on the prescribed treatment for as long as the veterinarian recommends.