Ringworm is not a worm- its a fungus! It often assumes a ringlike, scales, reddened shape on the skin of your pet, hence the name. Cats and kittens often have multiple ringworm sites on their bodies. Dogs generally only have a single lesion and its most common in puppies and immature dogs. Signs of ringworm are typically circular patches of skin or missing hair. Surrounding this area is a band of inflamed, reddened skin. The most common areas for ringworm to occur on your pet are their face, ear tips, tail, and paws.