Ringworm In Cats

“Ringworm” is a skin disease of warm-blooded mammals properly termed “dermatomycosis". It can be a major problem in multiple animal households and kennels/catteries.

It is caused by a fungal organism, not a “worm!”

Symptoms Of Ringworm:

The fungus lives in the outer layers of skin, hair shafts, and toe nails. It invades the hair follicles damaging the actual hair itself. The hairs become fragile and break easily.

Ringworm infections frequently appear as a dry, grey colored, scaly patch, but can take on any appearance and mimic many different skin diseases.

Some lesions may begin to heal and re-grow hair in the center, creating a circular lesion of hair loss, surrounding a central area where the hair may or may not be darker colored than normal. As the infection progresses, more and more hair may be lost and more skin lesions may appear.

After appropriate treatment, the hair will grow back though sometimes discolored.

Ringworm may result in secondary bacterial infections of the skin causing destruction of the hair follicles-so that hair may not grow back. It is important to initiate treatment early.

Dogs and cats become infected with the fungus by contact with other infected animals, infected people, or contaminated soil.

Diagnosis Of Ringworm:

Diagnosis is made by specific tests for ringworm, including skin scrapings, ultraviolet light observation, fungal cultures, and sometimes biopsy.

Treatment Of Ringworm:

Treatment may involve shampoos, ointments, creams, and/or systemic medications. Your veterinarian will determine the best treatment protocol for your cat based on your cat's physical condition and status.

Oral medications commonly used to treat ringworm are griseofulvicin and itraconazole. Both of these medications must be given with food and typically must be continued for 1-2 months. They are not safe for use in pregnant animals as both of these drugs can cause birth defects in unborn animals.

Lime sulfur is frequently used as a topical treatment. This is a dip which is applied to your cat's hair coat after bathing. The dip remains on the hair coat and should not be rinsed off. Caution must be taken in using this product. It must be diluted accurately, according to the labeling instructions, in order to avoid toxicity (poisoning). You should also be aware that lime sulfur dip will stain your cat's white hair yellow for a time. It will also stain clothing and jewelry. It has a very strong odor associated with it (it smells like rotten eggs).

Other products sometimes recommended are shampoos, creams, or ointments containing anti-fungal medications, such as miconazole or ketoconazole. Tame iodine (not tincture of iodine) also has some efficacy as a anti-fungal agent.

If secondary bacterial infections are present, antibiotics will be necessary to treat the pyoderma (skin infection), in addition to treating the fungal lesions.

It is also necessary to clean the environment concurrent with treating your cat for ringworm, as the fungal organisms can be shed in the environment and provide an additional source of infection. Carcats should be vacuumed thoroughly and the vacuum cleaner bags disposed of in the trash. Bedding and blankets should be discarded and replaced.

Infected cats remain contagious for several weeks after treatment is initiated. It is important for treatments to be performed properly and for adequate lengths of time. Your veterinarian will help you determine how long to continue treatment. Sometimes, repeating cultures of the skin and hair are necessary to insure that your cat is free of disease and the discontinuation of treatment is safe.

Ringworm is contagious to people. Caution should be used in handling animals diagnosed with ringworm. If you or any member of your family develop skin lesions after handling an animal with ringworm, you should consult your family physician.

Feline Health Care Corner Home Page

Feline Preventive Health Care

Feline Diseases

Other Feline Health Care Issues


The Pet Health Care Gazette Blog

Glossary Of Terms

About Us

Contact Us
Voice of Pet Care
Quick Search:

Subscribe To The Pet Health Care Gazette

Enter your email address to receive email notices:


Subscribe Through An RSS Feed Reader

Subscribe To The Voice of Pet Care Newsletter

Get up-to-date, essential news and information relative to your pet's health. Subscribe now.