Ringworm is also known as a fungal infection of the superficial layers of the skin, hair and nails. Ringworm infections can occur in humans and in all domesticated species of animals. The name comes from the classical appearance of the round, red, raised ‘ring’ marking the boundary of inflammation in people infected with the disease. The common name of ringworm is somewhat misleading, in that it is not an infection caused by a worm, and the infected areas are not always ring-shaped. The organisms that cause ringworm infections belong to a specialized group of fungi known as dermatophytes, so the medical name for this disease is dermatophytosis.
Some species of dermatophytes are species-specific, meaning that they will only infect one species, whereas others can be spread between different species of animals or from animals to man. In cats, one species of dermatophyte, called Microsporum canis, is responsible for almost all ringworm infections, and this species is infectious to cats, dogs and man. Occasionally ringworm infections in cats may be caused by species such as Trichophyton mentagrophytes. Both of these species are zoonotic, meaning that they can also infect humans.
