Ringworm, also known as dermatophytosis, is a fungal infection very common in cats. Ringworm fungus infects the superficial layers of the skin and nails. The most common species of ringworm fungus, Microsporum canis, is zoonotic, meaning it can be transmitted between cats, dogs and people.
Unlike the easily-spotted raised red circle seen in people with ringworm, the lesions may be more difficult to detect in cats. The skin may appear scaly and have round thickened patches of skin with hair loss. Patchy hair loss on the body is also common. The lesions are most commonly seen on the head, chest, along the back and on the forelegs. The lesions are not usually itchy.
Ringworm can be diagnosed by identifying the fungus through a culture sent to the lab, or sometimes can be found using a special ultraviolet lamp at the veterinary clinic. Ringworm is treated with a combination of topical antifungal shampoos and oral antifungal agents; treating the environment including furniture, bedding, combs and bowls is important because the fungal spores can remain dormant in the environment for months.