What is the fastest way to treat ringworm in cats?

Ringworm (dermatophytosis) is a common skin disorder in cats that is highly contagious to other pets and to people. Children and immunocompromised individuals (e.g. HIV/AIDS patients, cancer patients, patients on immunosuppressive medications) are especially susceptible to ringworm. This website addresses ringworm from a public health standpoint: CDC: Healthy Pets Healthy People: Ringworm

Cats with ringworm may or may not have visible skin lesions. Those who do have visible skin lesions typically have flaky bald patches primarily on the head, ears, and legs.

What You Can Do

• Your cat needs veterinary care. Ringworm left untreated can get progressively worse, and/or can increase the likelihood of spread to other pets and humans.
• Your cat needs to be kept away from visitors, immunocompromised individuals, and other pets until the ringworm infection is gone.
• Contact all visitors and other family members who came in direct contact with your cat. If they find any skin lesions on themselves, they should see their physician.
• Parents or guardians should closely monitor any children who came in direct contact with your cat. If any skin lesions are found on the children, they should be taken to a physician.
• Contact a veterinarian for advice if any of your pets have been directly exposed to your cat.
• Prevention of spread of ringworm and disinfection of the environment is very important. Ringworm spores can be very hard to eradicate from carpet and furniture. It is best to confine all pets with ringworm to one small room in the house that can be easily disinfected (e.g. no carpet, no fabric covered furniture).
• Everyone handling your cat should take precautions such as wearing gloves and a long sleeved shirt, washing hands, and vacuuming/disinfecting areas that your cat has spent time in.
• Household cleaners do not effectively kill ringworm spores. Disinfection should be done with chlorine bleach diluted 1:10 (1 ½ cups in 1 gallon of water), and care should be taken to avoid exposing pets or people to chlorine bleach fumes.
• This website gives great advice on how to disinfect: eHow: How to Disinfect for Ringworm.

Cause of Ringworm

• Ringworm, despite its name, has nothing to do with worms. Ringworm is a fungal infection (dermatophytosis) that can be diagnosed with a Wood's Lamp (ringworm lights up fluorescent green), a fungal culture, or a laboratory test.

Treatment of Ringworm

• The most effective treatment for ringworm in cats is lime dipping in combination with oral anti-fungal medication.
• Other treatments include the application of topical anti-fungal cream and bathing with anti-fungal shampoo.
• Program (lufeneron) has been shown to be ineffective against ringworm.
• Lime dipping in cats can be challenging! The following video has some great tips: Austin Pets Alive!: Cat Ringworm Treatment Training.

Helpful Links

Many medical terms are notorious for being confusing, but ringworm is undoubtedly one of the most misunderstood. Though people commonly assume this disease is caused by a parasite, ringworm in cats has nothing at all to do with worms. Ringworm in cats, also known as dermatophytosis, is caused by a fungal infection of the skin, most often caused by the fungus Microsporum canis,according to the Merck Veterinary Manual.

How Do Cats Get Ringworm?

The trouble with ringworm is that you really can't hide from it. Cat ringworm is caused by a fungal organism that lives just about anywhere in the environment. It is found in soil and thrives particularly in warm, humid environments. Ringworm agents aren't restricted to soil, though; the fungal spores are tiny enough that they can easily hitch a ride on blankets, clothing and fur and be transported indoors, where they can flourish as well.

Once the fungus finds a living food source, such as a cat, dog or human, it sets up shop in the hair follicle. It feeds on keratin, making hair, nails and skin its main nutritional sources. Here is where ringworm gets a little tricky; even if a cat becomes contaminated with the fungus, it doesn't mean they will always develop a ringworm infection, which is good news for pets and pet parents worldwide, said Cornell Feline Health Center.

Once on the cat, a meticulous self-groomer may simply rid the fungus from their coat. Other competitors, such as bacteria, thriving on the cat's skin may outnumber and defeat the fungus or the fungus may survive and stick around. While some cats can be asymptomatic when they are infected with ringworm, a number will develop clinical signs of infection.

What Are the Symptoms of Ringworm in Cats?

This is the only part of the name that warrants credit to those who coined the disease's name: ringworm often presents itself as a circular reddish rash — a ring — on the skin of an infected cat. Cats may begin to lose hair or develop a dull or stubby coat. Signs may progress to patchy hair loss, scaling or itchy skin and infected nails.

How Common Is Cat Ringworm?

While some diseases are rare, ringworm makes its rounds; it is perhaps the most frequently encountered infectious skin disease of cats worldwide. While it can affect any cat, kittens with less robust immune systems are more likely to develop an infection. Long-haired cat breeds are also more susceptible, along with cats in high-population settings (such as catteries), cats with other systemic diseases that may weaken their immune system or cats with poor nutrition.

Should I Be Concerned About Ringworm?

Yes and no. Ringworm in cats is not typically serious, but it can spread to people as well as other animals, such as dogs. Transmission occurs through direct contact between infected and uninfected individuals. It may be passed from cats to dogs to people in any number of spreading paths.

Adult humans are usually resistant to infection unless there is a break in the skin, such as a scratch, but children and the immune-compromised are especially susceptible. Seek care from your physician if you notice suspicious skin lesions similar to those described for cats. The good news is that because human hygiene is generally more thorough than our pets', a topical antifungal cream or spray may be all that is needed for human treatment.

Don't neglect the environment when dealing with a ringworm infection of either people or pets. The fungal spores may live in bedding or carpet for up to 18 months! A solution of bleach and water can be used to disinfect and kill the fungal spores: One pint of chlorine bleach (500 ml) in a gallon of water is effective on hard surfaces suitable for dilute bleach. This is very important to prevent recurrence of the infection.

What is the Treatment for Ringworm in Cats?

No one likes giving cats oral medications; luckily, there are topical antifungal medications available in the form of creams and sprays that may be effective against ringworm. Clipping fur and dips available at the veterinarian are also useful tools to rid the infection.

Oral anti-fungal medications, such as itraconazole, are often prescribed for more widespread infections or infections that do not clear up with topical therapy. They can be flavored like tuna or other popular cat treats to ease the administration of the oral medications. As mentioned above, environmental decontamination is always an important part of treatment to break the cycle of infection.

A culture for dermatophytes (the ringworm-causing agent) is the only means of truly monitoring a cat's response to treatment. When the infection is extensive or particularly resistant, treatment can drag on for weeks or months. This makes it more than worthwhile to have hair loss and lesions investigated and diagnosed sooner rather than later.

How Can I Prevent Cat Ringworm?

Preventing cat ringworm is challenging but not impossible. First and foremost, a healthy cat with a healthy coat and skin is less likely to develop ringworm from contamination with the fungal spores. Nutrition plays a vital role in maintaining the integrity of a cat's skin and hair follicles, where the fungal spores will fight to inhabit.

If you bring a new cat into the home, consider a quarantine period for the new addition, along with a culture for the ringworm organism, especially if the new cat has any signs of an unhealthy coat or skin.

If a pet is exposed to an animal with known ringworm, you may want to discuss with your vet the possibility of a prophylactic treatment using oral medications for up to two weeks. Ringworm can take weeks or months to clear when an infection has developed. Keeping your cat in their best health is the best way to ward off this itchy and lingering fungal skin infection.

Dr. Laci Schaible

Dr. Laci Schaible, is a small-animal veterinarian and veterinary writer. She has won numerous awards for her commitment to pet owner education and is considered a leading veterinary telehealth expert.

Written by Justine Lee, DVM, DACVECC, DABT

As a veterinarian, one of the most common fungal diseases that I see is ringworm in cats.

Years ago, I fostered a kitten that was brought in by a good samaritan. What I didn’t know when I was fostering her was that she would leave her infectious ringworm all over our house. This resulted in severe skin lesions on me, my husband, and my 13-year-old cat. It also contaminated our house with ringworm. Treatment was pretty intensive—not only did I have to shave all my cat’s fur off, but I had to give my poor cat a foul-smelling medical bath every 3 days. It also required about $1,500 of prescription oral antifungal medication, too.

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 a disease of the environment. The most common types of ringworm found include:

• Microsporum canis (commonly found on domestic animals)
• Microsporum gypseum (commonly found in the soil)
• Trychophyton m. (commonly found on rodents)

Cats can carry ringworm on their fur more frequently than dogs, and often don’t show any clinical signs from it—in other words, they may or may not be affected, but will likely shed it to their environment (including two-legged and four-legged pets, too!).

What are the signs of ringworm?

Signs of ringworm in cats include:

• Hairless regions on the face or body
• Broken hairs
• Red, raised, dry, circular patches on you or your family members
• Itchiness
• Scaling (e.g., white flakes on the fur)
• Crustiness on your cat
• Open, ulcerated bumps (e.g., nodules)
• Discolored areas of skin (especially in Devon Rex cats)

How do I know if my cat has ringworm?

Your veterinarian will have to do several tests to diagnose ringworm in cats; it can sometimes be diagnosed with a specialized light called a Wood’s lamp. More specific tests include a trichogram, fungal culture (submitted 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 needs to be tackled aggressively with topical lime sulfur baths, oral antifungal medication, environmental clean-up, and bathing.

Topical treatment includes bathing your cat with a medical lime sulfur dip twice a week. This typically comes as a concentrated form and must be diluted, or it can cause corrosive burns on the body. (It normally has to be diluted at 8 ounces of lime sulfur to one gallon of water). This needs to be done for 1-2 months or until your cat tests negative by 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 like itraconazole (typically at 5-10 mg/kg orally once a day for 3 weeks), fluconazole, terbinafine, griseofulvin, and ketoconazole. Rarely, there are potential side effects from the medication, so blood work should be done to monitor the bone marrow. I preferred the brand Sporanox, but it can be very costly. There is a newer prescription medication called Itrafungol™ that is FDA-approved for the treatment of ringworm in cats. It’s a cherry-caramel-flavored liquid.

Environmental clean-up is important too. This includes using a dilute bleach solution (1:10 dilution) or antifungal solutions (e.g., enilconazole solution, 0.2%) to clean the environment and minimize risk of continued contamination. I also recommend keeping any new pets out of the house for several months to minimize spread.

Can I get my cat’s ringworm?

Ringworm is zoonotic—in other words, it can spread from animal to human. If you suddenly notice red, hairless, dried circular patches on you and your family members, contact your medical doctor, as you may need treatment (which typically includes tough-actin’ Tinactin). Yes, the topical medication 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 embarrassed by! As a veterinarian, I’ve gotten ringworm after my stethoscope has touched affected animals, only to develop it all over my neck. The good thing is this is typically self-limiting (it’ll go away in you because you’re not the right host species for the fungus) and easily treatable with an OTC antifungal cream… but embarrassing nevertheless.

When in doubt, talk to both your veterinarian and your medical doctor if you think your cat may have ringworm. Treatment for ringworm in cats should be initiated as soon as possible!