How to Know if Your Cat Has Ringworm & What to Do
Ringworm is a skin condition caused by a fungus that grows on hair, skin, and nails. It can infect cats and easily spread to dogs and people. Know the signs and symptoms of ringworm so you can treat and prevent it from spreading. 
By Kristi Valentini Medically Reviewed by JoAnna Pendergrass, DVM Updated March 27, 2023 Medically Reviewed by JoAnna Pendergrass, DVM Advertisement Pin FB More Tweet Email Send Text Message Print 
longhaired cat looking out the window Credit: taseffski / Getty
Ringworm is a pesky skin condition that's common in cats. Despite the name, it has nothing to do with worms. It's caused by a fungus that spreads among animals—even indoor cats—and can infect people, too. Learn how to spot ringworm in cats and get rid of the infection for good.
What is Ringworm?
Ringworm (dermatophytosis) is caused by a microscopic fungus that's found in the dirt. It feeds off of protein in hair and skin. Kittens and long-haired cats are more likely to get this infection, named for the circle-shaped sores it forms on the skin. Ringworm is a zoonotic disease, which means it can be passed from animals to people. Your cat can give you ringworm and vice versa.
Signs of a Ringworm Infection
Some cats with ringworm have no signs of infection but can still pass it to other animals and people. Other cats develop severe ringworm symptoms.
A dead giveaway that your cat has ringworm are round bald patches that expose scaly pink sores. You're most likely to notice these infected spots on the face, ears, tail, and feet. But not all cats will have that symptom. Other signs your cat may have ringworm include:
- Bald spots with red, itchy bumps (which may have open sores on them)
- Constant grooming and scratching of the same area
- Ashy dandruff
In many cats, it can be tricky to tell whether they have ringworm. It can look like a lot of other common skin conditions in cats, such as flea allergy dermatitis and mange, says Jessica Lowe, DVM, medical director of VCA Beacon Hill Cat Hospital. She recommends making an appointment for an exam with your local vet, who can test for ringworm.
How Do Cats Get Ringworm?
One of the reasons ringworm is easily spread is because the spores (invisible seeds) it releases can live on surfaces for up to two years. It's even possible for indoor cats to get ringworm if they:
- Have contact with infected cats, dogs, people, or other animals
- Visit a grooming or boarding care facility where ringworm spores are present
- Touch furniture, carpet, or other surfaces containing ringworm spores
- Curl up in infected bedding.
Humans can get ringworm from petting an infected cat or touching anything in their environment. Young children, older adults, and those with weaker immune systems are more likely to get ringworm. Healthy adults are often resistant to it unless they have a break in their skin.
How Is Ringworm in Cats Diagnosed?
Healing a ringworm infection in cats takes time, so the sooner you're able to get started with treatment, the better. The first step to treating ringworm in cats is to eliminate other skin conditions through a proper diagnosis by your veterinarian. Vets often use a Wood's lamp (otherwise known as a black light) to identify ringworm. When exposed to its ultraviolet light, some types of ringworm have spores that glow green.
Even if your cat's skin doesn't glow under the special light, it's still possible they could have ringworm. Your vet may need to send a hair sample or skin scraping to a lab for further study under a microscope. Technicians can also perform a culture test, which is a method that encourages spores to grow so they can be analyzed. A culture test is the most reliable way to find out if your cat has ringworm, though it can take up to three weeks to get test results.
How to Treat Ringworm in Cats
Be wary of home remedies and over-the-counter ringworm treatments for cats, Lowe says, since none have been proven to work. Veterinarians typically treat ringworm in cats with a combination of antifungal medications: Some ringworm treatments are applied topically to the skin, while others are medications that are given to your cat orally. Your vet may also recommend medicated baths.
Lowe says you should start to see an improvement in your cat within four weeks. But keep in mind, your kitty will still be contagious for at least three to six weeks after starting aggressive treatments.
Be sure to follow through with their treatment plan as directed, even if your cat starts to look and feel better before treatment is finished. It's crucial to continue giving your cat antifungal medication for the length of time your vet recommended since ringworm is likely to return if you stop treatment too soon.
How to Prevent Ringworm from Spreading
An essential part of treating ringworm in cats is to stop it from spreading in your home—especially since it can be contagious to other animals and people. Although it might be hard, avoid petting a cat with ringworm. Also, keep the infected cat separate from other pets and people at home, and wash your hands anytime you touch them.
To prevent ringworm from spreading, it's important to clean surfaces and items where their spores may have spread, Lowe says. Wash all fabrics in the home. If they can't be washed, vacuum them. Sanitize cat toys, combs, and brushes, and clean surfaces with a diluted bleach solution.
Left untreated, ringworm usually goes away on its own, though it may take up to a year (and can infect others in the home during that time). To get your kitty feeling better faster and prevent ringworm from spreading, see a veterinarian as soon as you notice symptoms.
