If you’ve been caring for cat colonies, barn cats, or fostering kittens, you’ve probably gotten some experience with ringworm by now. Ringworm and cats are often linked together in very negative ways.
There are many causes of ringworm and cats are only one of them. Cats are often blamed for it in people, horses, and other pets.
Ringworm sounds super scary, but it really isn’t. It is a common issue in outdoor cats, shelters, and especially kittens. So let’s learn what ringworm actually is, the causes of it, symptoms of it in cats, and the treatment options available.
Disclaimer: I am not a veterinarian. This article is for educational purposes only and should not be used to diagnose or treat any illness or disease. Please discuss any health issues regarding your pets or cat colony with your veterinarian.
Disclaimer: This post contains affiliate links. I may earn a small commission from qualifying purchases, at no cost to you. Read the Affiliate Disclosure for full details.
Ringworm is a fungal infection of the skin. It is not a worm or parasite. It is called ringworm because it can cause a circular red rash that is shaped like a ring. Not all infections will cause the circular rash, though.
Depending upon where the rash is located, it often has different names. Ringworm of the feet is often called athlete’s foot. Ringworm in the groin is called jock itch. Your fingernails and toenails can contract this fungal infection too and it won’t be called ringworm. But it is the same thing. If you want a full list of various names for these fungal infections, you can find them here.
Ringworm is called tinea or dermatophytosis in medical terms. Tinea corporis is the medical term for ringworm of the body, the most common type of fungal infection known simply as ringworm.
About 40 different species of fungi can cause ringworm. You heard that right. FORTY DIFFERENT KINDS! The most common class of fungi that cause skin infections are called Dermatophytes. These fungi obtain nutrients from the keratinized material of humans and animals, such as nails, hair, feathers, etc. This is why they infect the outer layer of the skin. But let’s not get too technical.
Depending upon where the infection is located, it could be called ringworm or it could be called athlete’s foot. That said, in cats, it’s just called ringworm no matter where it’s located.
Fungi thrive in moist, warm environments and common sources of fungal skin infections include locker rooms, tanning beds, skin folds, swimming pools, exercise machines, and even your garden soil!
Risk factors for contracting ringworm include using public showers, contact sports such as wrestling, excessive sweating, contact with animals, obesity, poor immune function, and poor hygiene. Children (and kittens) as well as those with a depressed immune system are most often infected.
Some species of dermatophytes are species-specific and only infect that species. Some species can infect a wide variety of animals and humans.
In cats, the species that is most often the cause of ringworm is Microsporum canis, which can infect cats and sometimes dogs, horses, and people. In fact, 98% of ringworm cases in cats are caused by this one species, according to the Merck Veterinary Manual. Other types of ringworm, such as the species that live in soil, can also affect cats and people.
Ringworm in cats can often be asymptomatic, which results in a carrier condition. This simply means that a cat can spread ringworm but has no symptoms of an infection. The cause of ringworm in cats is contact with infected animals, objects, or environments.
That said, ringworm might be contagious but it isn’t THAT contagious. It is not uncommon to only have one or two cats or kittens infected, while the rest of the household or colony shows no symptoms at all. That is because most adults (both human and cat) are often resistant to infection. But prolonged exposure increases the risk of infection in healthy adults.
The incubation period between exposure to ringworm and the development of symptoms is 7-21 days. This means if you pet a stray cat yesterday and have ringworm today, then that is not the most likely cause of your infection.
The most common symptom of ringworm in cats is no symptoms at all! But every cat is different and may or may not have one or many of the following signs of ringworm.
Kittens are most often infected as their immune systems aren’t fully developed. Kittens are also more likely to have more severe types of ringworm infections as well. Elderly cats and cats with a weakened immune system are often more likely to get ringworm.
Only a licensed veterinarian can definitively diagnose ringworm in your pet or feral cats. The most reliable way a veterinarian uses to diagnose ringworm is by sending samples to a lab, but that can take a couple of weeks. Faster, less accurate ways exist, such as using a UV lamp to check for glowing strands of hair (this occurs about half of the time in ringworm infections) or by looking at skin scrapings under a microscope.
That said, if you have a lot of experience with cat colonies, kitten fostering, and animal rescue and animal shelters, then you might be able to make an educated guess based on experience.
Here’s some good news: Ringworm SOUNDS scary but it really isn’t! Ringworm is usually mild and self-limiting in adult cats. That means it’s a minor issue and will often resolve on its own. Most adult cats and humans are often resistant to infection so the chances of you catching ringworm from your infected cat is very low, even if you weren’t being careful. And if you or your cat do catch ringworm, it’s super easy to treat. It just takes time.
Sometimes no treatment is necessary. Most mild ringworm infections in cats will heal on their own due to a cat’s immune system. That’s excellent news for us feral cat caretakers! I don’t bring in my barn cats or cat colony for ringworm unless it is making the cat miserable or it is severe or persistent. The trauma of treating an unsocialized cat for ringworm and bringing him into the vet is more harmful than the ringworm infection itself.
That said, treating your pets and yourself can help reduce the length of infection and help stop it from spreading to other animals. And ALWAYS treat kittens who are infected. They do not have strong immune systems.
It is always best to isolate the infected cat from others to help stop the spread of ringworm, if possible. The environment (i.e. the house) must also be treated if you want to completely cure the infection.
The most common way to treat ringworm is to use topical antifungal medications. This may include creams, medicated antifungal shampoos, or a lime sulfur dip. Or a combination of all of these. Always follow your veterinarian’s instructions.
If the cat is a long-haired variety, your vet may suggest clipping the fur to help make treating the cat easier.
For more severe infections, your veterinarian may prescribe an oral antifungal medication as well as those topical options listed above. (I have included examples in the links, but what your vet recommends might be different!)
Despite the fact ringworm is not seriously infectious nor is it usually a huge health issue, it’s always a good idea to do what you can to prevent you and your cats from getting ringworm in the first place. Ringworm might not be scary, but it can take weeks to be rid of it and it can cause uncomfortable itching and unsightly lesions. Another big reason to try to prevent ringworm is so that you don’t spread it to a more vulnerable person or animal who may get more severe symptoms and who may have problems being cured of infection, such as immune-compromised individuals and pets.
So how do you prevent ringworm?
Ringworm can stay infective in your home and other environments for up to 18 months. That’s a year and a half!
If you have a cat with ringworm, always quarantine them to one room that is easy to disinfect. It’s much harder to keep an entire house clean and disinfected than it is to regularly clean and disinfect one room.
Always see your veterinarian if you have concerns about your cat’s health. Ringworm is NOT the only skin issue that causes hair loss and lesions. Appearance alone is not enough of an indication of ringworm.
Cats are not the only source of ringworm. In fact, they’re only ONE source of ringworm. Poor hygiene actually causes a lot more fungal infections that cats do.
Did you know? Cats that have poor grooming habits are at increased risk for contracting a ringworm infection than one who grooms himself regularly. Poor hygiene issues affect cats too!
Remember, it’s also not a huge deal for most cats or people. It’s a simple, easily treated infection that can be cured with the right treatment.
What’s your experience with this dreaded fungus? Tell me below by leaving a comment!
Lovies!
This post was last modified on September 12, 2020 2:48 pm
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It's been many years ago when I had two cats. My issue was being allergic to them.
But I don't remember them ever having ringworm, although it is a common problem for cats.
Having an animal is like having a child in many ways. You have to feed them and take care of them and that means trips to the vet and having something like ringworm taken care of. You want to say on top of this.
You've got some excellent suggestions here. Great Job!
Thank you!
This has been an extremely informative and educational post on ringworm in cats and I never knew that ringworm was caused by different species, I thought it was just one. I grew up with two beautiful Siamese cats in the family, but I cannot remember that either of them ever had ringworm, or that any of my sisters had ringworm passed on to us from the cats. So do you think this is more of a modern occurrence?
Hi!
No, I don't think this is more of a modern occurrence. Ringworm is more common in certain areas than others, such as in the Southern United states because it's warm and humid. Fungi of all kinds, including ringworm, enjoy warm and humid. It's rarer in desert climates or colder climates, or it likely only shows up during certain seasons in some areas. That said, as the temperature of the earth warms up, it might be showing up more often in climates that don't normally see much ringworm.
It's also much more common in outdoor cats, feral cats, shelters, and in kittens than in pet cats.
HI! Thanks so much for this! I am taking care of my neighbors cat who sadly has had ringworm for many months (they thought it was fleas and finally caught it so now it's terrible). She is older and honestly I cried when I saw her - I love Pepper and hadn't seen her in a long time due to COVID and when I saw her I just cried. She has lost all of her hair and I don't think they're keeping the area as clean as it could be. ANYWAY! I have four cats. One with a compromised immune system so I am maybe freaking out a little. Your post made me feel a little better though, because yes, on day One I did pet Pepper with my bare hands but I scrubbed them with a pot scrubber, took off all of my clothes and took a shower when I got home. I left my shoes outside and have continued to leave them outside and spray them with bleach each time I use them. I also discovered an old steamer my mom gave me and I steamed the carpets in my house today and the floor. I just hope I am not too late because it has been two days and I'm just steaming things. I guess I'll find out in 2 weeks if we got away with it. :) Thanks again for your post - Greetings from Humid Florida!
Hi, Mary!!
You're very welcome and greetings from humid Louisiana!! Hopefully, you caught it before your immune-compromised kitty catches it, but with treatment, immune-compromised cats can recover fairly easily too! It's just cats with competent immune systems can and do fight it off on their own and may not catch the infection. The poor kitty with ringworm though sounds like she's miserable. Hopefully, the neighbors will treat her too.
I've had ringworm transferred inside to a kitten I was fostering from a barn cat with ringworm (I pet the barn cat and transferred it to the kitten without catching it myself!). The kitten lost all the hair on his tail, but not one other cat caught it while I was treating him. AND it was like two weeks before I figured out what the kitten had. I had never seen it like that on the kitten so didn't recognize it until I FINALLY got ONE spot after two weeks of constant exposure. My one spot was easily treated and didn't spread and the ringworm itself only infected that one kitten.
It's contagious, but if any of your indoor cats get it, it likely won't be them all unless you have super bad luck. And it's so easily treated that even if that DOES happen, it's not horrible. It's just a pain if you're dipping the poor kitty or using antifungal shampoos because most cats are terrible about being wet. You can spot treat the spots in short-haired cats with kitty antifungals and it might clear up immediately. If a particular infection is bad, then a trip to the vet is warranted for prescription oral antifungals. It can take some time to clear up, so it's definitely not fun, but it's really not that contagious.
I'll keep my fingers crossed that you disinfected enough, simply because it IS a pain. Thank YOU for visiting and your kind words!
Hello Rochelle, well, today I finally took one of my indoor cats, Freddy to the vet, and sure enough... he has ringwom!, I have 5 cats in one big room to keep them away from my dogs so recently, I rescued 2 feral babies, which I believe that's how Freddy got it. None of my other cats, yet... seem they have any symptoms but ill keep checking. I gave him his bath with the prescribed shampoo, cleaned the room with diluted Clorax, washed cat toys, food bowls etc.. I ordered some anti fungal wipes for cats, dogs and horses, so I will wipe down the others till Freddy gets better. Do you think using the wipes for my other fur babies will prevent them from not getting it? What do you recommend ?
Thank You for your incredible hard work and your informative information! We need more people like you!
Hi, Beth!
I do think the anti-fungal wipes will definitely help keep the others from getting it, although of course nothing is 100% guaranteed. What happens a lot of the time, is that a cat will not show symptoms but will be a ringworm carrier. I think the wipes will also help keep those cats from spreading it back to Freddy, as well.
Honestly, the medicated bath and/or lime sulfur dips are more effective than wipes (because of fur, obviously), but I wouldn't want to bathe or dip five cats twice a week (or however often your vet recommended) either. For one thing, I have two that would rip my face off if I bathed them EVER. So wipes are an excellent idea!
I haven't used many different brands of medicated wipes, but the one I did use that I found effective on ringworm (and chin acne in cats) I purchased from Chewy here: https://prf.hn/l/640OGaA or on Amazon here: https://amzn.to/3ooz6kX. There are also antifungal sprays from Chewy or Amazon that can be useful to spot treat a spot or two if the vet hasn't given you one. Another suggestion is antifungal creams in between bathing of the infected cat.
The rest that you're doing is the best way to prevent the spread of it. Even if a cat develops a spot that you can't see, most of the time it is self-resolving, meaning the cat will heal it on his or her own, with no help. But using antifungals will help it to stop spreading and heal a bit faster.
Hope that helps. Thanks for rescuing the feral babies, even if they gave your poor fellow ringworm!
Hello,
I have a 1 year old cat that I rescued a year ago (when he was a 5 week old kitten). I made the mistake of letting him be an indoor/outdoor cat because he loved the garden so much. Well....2 and a half weeks ago I took him to the vet to see why the hair on his "knee" was gone and it turns out he has ringworm. I understand it is easy to treat, he is on Itrafungol and gets medicated baths twice a week, but what is KILLING my soul is that he cries and cries and just wants to be outside where he is happy. He is miserable inside. My question is....when this clears up, what are the chances of him getting it again? I have supplemented his diet with L-Lysine and plan on continuing the twice weekly baths. My heart just breaks for him, I can't even bear to let the dog outside because he sits and cries at the patio door watching her. I don't know what to do and I'm heartbroken.
Hi, Anita,
Unfortunately, it's quite common in cats who have access to the outdoors. It's possible he may never get it again. It's also possible he contracts ringworm every single time he encounters the fungal spoors outside.
I do not recommend bathing a cat twice weekly unless it's medically necessary, such as an ACTIVE ringworm infection that needs the bathing. I would NOT continue bathing him after the ringworm clears up. Regular bathing of cats actually does more harm than good. It strips their fur of their natural oils, dries out their skin, and most importantly, often destroys the trust the cat has in you. They'll tolerate it for a time as long as the torture ends. But most cats don't like being wet as their fur isn't designed to be wet.
Also, while L-Lysine is 'marketed' for immune support, there is actually no evidence it affects the immune system at all. It's a marketing scheme when people started trying it out to help cats with active Feline Herpesvirus stop having upper respiratory infections. All studies on it pertain to the Feline Herpesvirus and it performs no better than a placebo in the case studies with that particular virus. I would use actually PROVEN ways to increase a cat's immune system, such as better quality foods high in protein and nutrients, such as Purina Pro Plan, Iams, Royal Canine or Hill's. Supplement with Arginine has actually proven in a study to help a cat's immune system. Another option is probiotics have been proven to help the overall immune system, not just the gut.
Hope that helps!
Rochelle, I beg to differ. I gave my cat Odin who has a cleft palate Llysine and it worked wonders; every time I stopped it, his sinuses flared up. It does help with the immune system. I myself have taken it for herpes and it disappeared within a couple of days,
You're welcome to believe whatever you wish to believe. But I need actual evidence. Just find ONE peer-reviewed study done where lysine performed BETTER than the placebo did in cats OR humans. I'll take EITHER ONE! Just one link to one independent scientific study.
The problem with anecdotal evidence ("I tried it and my symptoms got better!") is that you don't know WHY your symptoms got better, or in this case the cats. Herpes flares up and goes away, both in cats and in humans, all of it WITHOUT TREATMENT. So you don't know IF that flare was a short flare or not, whether or not you were taking other medications, etc. You have no idea WHAT actually caused it to go away. Whether it was your own immune system or the lysine.
That's why they do actual studies where they give a BUNCH of cats lysine and a BUNCH of cats a 'fake lysine' and determine if the REAL 'lysine' group actually had more cats get better OR if BOTH groups of cats got better the same!
Because not all medication works on every cat or person. For example, novocaine and lidocaine doesn't work on me. Like except in EXTREMELY HIGH doses. But my neighbor would be numb for half a day with one tiny child dose. Does that mean novocaine doesn't work at all then, because I don't have a response to it? Obviously not, more people react to the medication that the people that don't! And we learn that through SCIENTIFIC STUDIES. Heck, I knew a guy who was so sensitive to ibuprofen it made him high. Just because it made ONE person high, doesn't mean ibuprofen makes people high!
Do you get my point here?
One cat getting better isn't evidence. It isn't even proof if he got better every single time, because maybe, that particular cat only flares up for a couple of days each time and it goes away on it's own pretty easily. OR perhaps the antiviral medications that were given were ACTUALLY the reason why the cat got better.
Like right now, I've got a cold. It's viral. If I took Cold Eeze and started feeling better tomorrow, would it be because my immune system works well or because of the Cold Eeze? We don't know. Except recent studies have found that Cold Eeze and other medications do NOT shorten the length of the cold any better than NO treatment. So obviously, I'm not going to argue with science just because I THINK that I got better on it. By reading the studies, I'd know it was my IMMUNE SYSTEM that worked, not the medication, so I won't waste money on it again.
And seriously, I am MORE than willing to buy and use lysine. If just ONE of these people arguing with me can provide ONE study where it actually WORKED. Just one. I'm not picky, one for humans OR felines.
From what I understand, once they've had ringworm, they usually develop an immunity to it. I've been reading A LOT about it. I think there's even a vaccine for it, although it's not very effective.
Hi, Anita,
It's untrue that cats develop an immunity to it after being infected. Not one single reputable veterinary source has suggested it at all. Some cats don't become infected after being exposed, and simply turn into CARRIERS of it, but cats can get infected over and over and over again as long as they are reexposed to the fungal spores. Just not all cats show ringworm SYMPTOMS.
Indoor-only cats don't often get reinfected because it's usually a new cat to the household that infects them in the first place and as long as no new cats are introduced again and the environment cleaned, they don't get it again. But that has nothing to do with immunity.
Only certain DNA viruses like chickenpox give lifetime immunity after being infected once. A lot of other viruses offer immunity for a limited time, such as COVID. Bacterial and fungal infections are usually exempt from the immunity thing, though some can be vaccinated for.
As for the vaccine, there IS a ringworm vaccine, but it has been deemed INEFFECTIVE in cats. Meaning it doesn't work at all.
There are a ton of different species of fungus that causes ringworm symptoms. Just as there are millions of different viruses. To say getting it once grants immunity to it is like saying getting one cold makes you immune to colds. It definitely doesn't.
That's why cleaning the environment after ringworm infection is important. You can reinfect the cat or other animals and people in the house.
I also have a feral barn cat that gets infected with ringworm every single year, so I have witnessed it first hand. He also experiences it in the exact same spots in a HORRIBLE manner.
Thank you for the helpful information in your blog post and your responses to commenters.
We adopted two kittens and felt a small bump, like a pimple on their ears. Three days after adopting them, we the “pimple” worsened, and our vet confirmed they have ringworm.
We have quarantined them on our master bedroom which was their original safe room. We have thrown out the mattress, disinfected multiple times, and now sleep in our guest room. For two weeks, we left a small bookshelf with about 30 books in the bedroom. Of course, when we would enter the room to treat or feed the kittens, the books were knocked around on their shelves because the kittens had jumped up and sat on a shelf or two.
We put all the books in the sun for about four or five hours, as we heard sun can kill the spores. We are both professors and book lovers. Since ringworm spores can live in on objects for up to two years, have we, now, lost this book collection? Or, do you or does anyone who has studied dermatophytes know how to rid spores from books. Absolutely nothing shows up when Googled—we have tried multiple forms of keyword and key-phrase searches.
This particular bookshelf was where we kept new books we had ordered for our current research, so most had not yet been read. It would cost many hundred Fred’s of dollars to replace them all. Do you have any advice?
Thank you!
Hi, Lana! Thanks so much for the compliment!
Ringworm and other similar fungal infections are best spread in humid, dark places. This is why locker rooms and soil tend to spread things like athlete's foot, which is a fungal infection of the feet, or jock's itch, which are fungal infections of the groin. These are all human species of ringworm that humans regularly catch.
So you had the right idea of leaving the books out in the sun. It DOES kill ringworm spores on objects that can't be wiped off with a disinfectant. This is coming from veterinary doctors who specialize in ringworm and other skin issues in pets. These vets specifically state ringworm is killed by sunlight. No need to replace them all!
If you feel especially paranoid about ringworm, leave them out again in the sun during the hottest part of the day a few hours each day for a few days. But chances are that they're already dead/gone. Fungal spores don't survive long in direct sunlight.
Hope that helps!
Thank you so much!
- Lana
Hi!
Thanks for the information you were quite informative. I have three cats. All rescues, and we recently rescued another kitten that does have ringworm. She has been isolated and we have been giving her the treatment her foster mom started her on. It’s an oral medication taken for one week, then one week off and on more week on. Today is the last day, and my boyfriend and I intend on cleaning everything in the room today and giving her a little bath. My question is would she be able to finally meet the other cats tomorrow and roam around a bit? She’s been stuck in the bathroom for five days and the cats are comfortable enough now to meet. We just want what’s best for her and the other fur babies!
Hi, Paige,
As long as she's hasn't been showing any symptoms this entire time, it should be fine!
I have had barn cats and kittens for 25 years and this year, for the first time, the kittens got ringworm. I took them out of the barn and kept them in a metal dog pen and treated them with antifungal cream and bleach bathes. They did not get any better, and one actually got worse. None of my adult cats show any signs. I finally let the kittens out and all tbree of them are fine. The black one, who was the worst, had brown fur where it grew back. How do I get my barn environment clean? I am planning to clean it out, but is there anything to put in the stalls that have dirt floors? Or to spray on the wooden boards? Any help would be appreciated. Thanks!
Hi, Nancy,
Sunlight kills ringworm. You don't really need to worry about disinfecting the barn. For one thing, it's not THAT contagious. For another thing, dirt and other areas where sunlight doesn't reach will grow fungal spoors no matter what you do. It's how they catch it, from the ground and environment. It isn't a specific virus that causes it. It's HUNDREDS of types of tiny, microscopic fungi species that cause it. I would not worry about doing any cleaning outside. Just let the sun in the barn.
Also, please don't do bleach baths on kittens. Bleach can be pretty caustic and kittens already hate water, they likely accidentally inhaled the bleach water AND they most definitely licked it off themselves. A better alternative for kittens is using a lime-sulfur dip or an antifungal shampoo safe for pets. That way, it's not toxic if they ingest it nor will it eat through their fur or skin.
Hope that helps!
Here it has been a huge ringworm crisis as I have 8 adult cats and 5 kittens - with NO way to quarantine them as my home is small (1000 sqft home) and has only 2 bedrooms plus they do not stay in one room but zoom out. I do not have a garage. This has been a disaster and no help whatsoever from anyone. Out of the 13 cats, 8 or 9 have it. No lesions on the others (the oldest is 15.5 years old has no lesions) . So, what do I do?
Hi, Skye,
5 of the ones that have it were kittens, I take it. Deep breath. Just keep treating them with lime sulfur dips or anti-fungal shampoos. And honestly, it will likely clear up on its own without treatment anyway. Ringworm usually does!