Ringworm in Cats

Ringworm in cats, or dermatophytosis, is a fungal skin infection that affects cats' hair, skin and nails. Ringworm is contagious to both dogs and humans; those with a lowered immune response are especially vulnerable to the risk of ringworm contagion. Though ringworm in cats often clears up on its own with time, the risk of contagion means that you should be aware of its symptoms, transmission and treatment.

The Cause of Ringworm

While there are several different fungi that cause ringworm, most cases of in cats are the result of fungi in the Microsporum canis, Microsporum gypseum or Trichophyton species. The fungus that causes ringworm are usually found on the infected animal or in its living quarters. An infected animal can shed spores that can live in the environment for up to two years.

Ringworm fungus thrives in warm, humid environments. Spores can live on bedding, furniture and anything else that has come into contact with the infected animal. Cats can become chronic carriers, harboring and shedding the fungus without showing signs of infection.

Transmission of Ringworm

Ringworm is transmitted by direct contact with fungal spores. Spores can survive in bedding, grooming equipment and boarding facilities inhabited by an infected animal. Because the ringworm fungus can live for up to two years in the environment, your cat can contract ringworm from anyplace where other animals have been.

Most healthy adult cats, however, enjoy some natural resistance to the fungus and may never show symptoms. Cats with suppressed immune systems are most vulnerable to developing symptoms of infection. Older cats, free-roaming cats, stressed and malnourished cats are at increased risk to develop an infection; Persian cats also seem more susceptible to infection.

Symptoms of Ringworm

Ringworm in cats causes skin lesions which can differ in appearance. The most common type of lesion is small, round and hairless. Scaly skin may appear in the center of the lesion. Small pustules may also appear.

Ringworm lesions may begin small and grow in size. They may become irritated and itchy. They are most commonly found on the head, ears and tail. Sometimes, the fungus can spread over the face, lips, chin and nose; it can be difficult to distinguish the symptoms of ringworm in cats from those of other skin diseases.

Diagnosis and Treatment of Ringworm in Cats

One of several tests is necessary to diagnose ringworm in cats. Many types of ringworm fungus will fluoresce under a special type of black light known as a Wood's lamp. However, this test is not entirely accurate as other substances in your cat's fur can fluoresce as well.

Some ringworm infections can be diagnosed by examining hairs from the lesion beneath a microscope. However, the most reliable means of diagnosis involves collecting scales from the lesion and performing a fungal culture.

In healthy cats and kittens with small lesions, ringworm can be treated with an anti-fungal cream. In more severe cases, a combination of oral and topical medications can be used. Lime sulfur dips are the topical treatment of choice for ringworm in cats.