written by justine lee, dvm, dacvecc, dabt
As a vet, one of the most common fungal diseases I see is ringworm in cats.
Years ago, I raised a kitten brought to me by a Good Samaritan. what he didn’t know when he was raising her was that he would leave his infectious ringworm all over the house. this resulted in severe skin lesions on myself, my husband, and my 13-year-old cat. He also contaminated our house with ringworm. the treatment was quite intensive, not only did i have to shave all my cat’s fur off, but i also had to give my poor cat a smelly medical bath every 3 days. it also required about $1,500 worth of prescription oral antifungal medications.
so what is ringworm in cats and what do you need to know as a cat parent?
Ringworm, often called dermatophytosis, is a fungus that is an environmental disease. the most common types of ringworm found include:
- microsporum canis (commonly found in domestic animals)
- microsporum gypseum (commonly found in soil)
- trychophyton m. (commonly found in rodents)
- hairless regions on face or body
- broken hairs
- red, raised, dry, circular patches on you or your family members
- itching
- scaling (eg, white scales on fur)
- bark on your cat
- open, ulcerated bumps (eg, nodules)
- discolored areas of skin (especially in Devon Rex cats)
Cats can carry ringworm on their coats more often than dogs and often do not show any clinical signs; in other words, they may or may not be affected, but they are likely to spread it to their environment (including two-legged and four-legged pets too!).
what are the symptoms of ringworm?
signs of ringworm in cats include:
How do I know if my cat has ringworm?
Your vet will need to do several tests to diagnose ringworm in cats; it can sometimes be diagnosed with a specialized light called a wood lamp. more specific tests include a trichogram, a fungal culture (sent to a lab), a pcr test, or even a dtm test.
what is the treatment for ringworm in cats?
so what’s the treatment? ringworm should be aggressively addressed with topical lime sulfur baths, oral antifungal medications, environmental cleansing, and baths.
Topical treatment includes bathing your cat in a medicated lime sulfur bath twice a week. this usually comes in a concentrated form and must be diluted, or it can cause corrosive burns to the body. (normally has to be diluted in 8 ounces of lime sulfur to one gallon of water). this should be done for 1-2 months or until your cat has a negative skin culture for at least 2 tests in a row. i also found that shaving my cat (down to the skin) helped with bathing and minimizing shedding around the house. other topical options may include antifungal/chlorhexidine combination shampoos.
Oral antifungal medications should also be used to treat ringworm in cats. these include drugs such as itraconazole (typically 5 to 10 mg/kg orally once daily for 3 weeks), fluconazole, terbinafine, griseofulvin, and ketoconazole. rarely, there are possible side effects of the drug, so blood tests should be done to check the bone marrow. I preferred the sporanox brand, but it can be very expensive. There is a newer prescription medication called itrafungol™ that is FDA approved for the treatment of ringworm in cats. it is a cherry and caramel flavored liquid.
environmental cleanliness is also important. this includes the use of a dilute bleach solution (1:10 dilution) or antifungal solutions (eg, 0.2% enilconazole solution) to clean the environment and minimize the risk of ongoing contamination. I also recommend keeping new pets out of the house for several months to minimize spread.
can I get ringworm from my cat?
ringworm is zoonotic; in other words, it can be transmitted from an animal to a human being. If you suddenly notice red, dry, hairless circular patches on yourself and your family members, contact your doctor as you may need treatment (usually including long-acting tinactin). yes, the topical medicine used for jock itch or athlete’s foot is also used topically for human ringworm infections, that’s because it’s the same fungal infection.
Fear not: it’s nothing to be ashamed of! As a vet, I got ringworm after my stethoscope touched affected animals, only to develop it all over my neck. the good thing is that this is usually self-limiting (it will go away on you because you’re not the right host species for the fungus) and can be easily treated with an over-the-counter antifungal cream… but it’s still embarrassing.
When in doubt, talk to your vet and your doctor if you think your cat may have ringworm. treatment for ringworm in cats should be started as soon as possible!
