Dermatophytosis is a clinical condition caused by fungal infection of the skin in humans, pets such as cats, and domesticated animals such as sheep, goats and cattle. The most common term for the infection, "ringworm", is a misnomer, since the condition is caused by fungi of several different species and not by parasitic worms. The fungi that cause parasitic infection, collectively dermatophytes, feed on keratin, the material found in the outer layer of skin, hair, and nails. These fungi thrive on warm and moist skin, but may also survive directly on the outsides of hair shafts or in their interiors. In pets, the fungus responsible for the disease survives in skin and on the outer surface of hairs.