Ringworm in Cats and Dogs

Ringworm is not actually caused by a worm, but rather by a fungus that infects the outer layer of skin and hair. It is a zoonotic disease, meaning it can be transmitted from pets to humans, or people to pets. There are numerous species of ringworm. It is most commonly recognized in cats (often kittens) and dogs, although rabbits and rodents can also become infected. Ringworm can be very contagious.

Can I Get Ringworm from My Pet?

Yes. Anyone that has come into contact with the infected animal or its environment has the chance of contracting ringworm. In people, the infection may appear on the skin as a ring with reddish borders and is usually itchy. If you have any concerns about ringworm in family members, please seek advice from your physician.

How is Ringworm Treated?

Ringworm is easily treatable in humans with only topical medication. However, this is not the case with pets. In order to eliminate ringworm from animals, topical and oral anti-fungal medications are required, and it often takes months for complete resolution. Oral medication is either itraconazole or fluconazole. Topical medications are daily miconazole or clotrimazole creams plus weekly lime sulfur dips. Once the skin starts to improve, a fungal culture will be obtained and sent out to monitor the status. As soon as there is one negative culture, a second culture will be sent to the lab. Dermatologists recommend that treatment be continued for one month beyond the second negative culture. It is important that your pet receive their medication and treatment regularly.

How Do I Clean My House?

• Ringworm spores can survive in the environment for two years. Pets and people can become re-infected if the house isn’t properly cleaned.
• The best product to kill ringworm is bleach (1:10 dilution with hot water). You can also use Lysol with Bleach or 409. Make sure to use any product liberally and repeat cleaning daily.
• Vacuum carpets, floors, and furniture frequently and dispose of the vacuum bag immediately.
• All curtains, comforters, etc. should be dry cleaned at a professional cleaner.
• Clean all air vents and change filters often.
• It is also recommended that items that cannot be bleached (e.g. floor rug, couch, etc.) be placed outside in the sun on a hot day.
• Wash all sheets, blankets, towels, pet beds, plush toys, pet brushes, etc., bleaching items when possible.
• Throw away anything that cannot be fully cleaned.
• Be sure to talk to your veterinarian if you notice any changes in your pet’s behavior or if your pet does not appear to be improving.

Sources:

University of Guelph, Worms and Germs Blog
WebMD, Ringworm of the Skin