Although the name often misleads pet owners into thinking a worm has invaded their pet’s bodies, ringworm is actually a fungus that can affect the hair, skin and nails. This fungus can lead to circular patterns of hair loss and red, scabby bumps. Before you introduce another pet into your home, knowing the facts about ringworm and how to prevent the skin condition from spreading is crucial. Dermatophytes, fungi that feeds on protein in the skin, hair and claws, is the agent of ringworm. Infections are transmitted by contact with infected hairs from another infected pet in the environment, or through bedding, grooming tools, and even fleas. The fungus can be passed between animals and humans, but young and elderly people are more susceptible to developing the infection. Those with weak immune systems are also more prone to ringworm.