10/09/2026
🍄 LET'S TALK ABOUT RINGWORM (AGAIN)
On this week's run up to the Feral Cat Spay & Neuter Project in Lynnwood, we had three kitties with suspected ringworm.
ACK!
Thankfully, Feral Cat is the bomb dot com. They still carefully serviced all three, and let us know what they were seeing so we could follow up. That is exactly the kind of partner you want. They are awesome and WE LOVE THEM!!!
Now our job is to work with the clients on resolving it.
FIRST - RINGWORM IS NOT A WORM
Despite the name, there is no worm involved. Ringworm is a fungal infection of the skin, hair, and occasionally the nails. The medical name is dermatophytosis, and the species we see most in cats is Microsporum canis.
It spreads mostly by direct contact with an infected animal, but also through spores, which are remarkably tough and can survive on bedding, towels, grooming tools, and clothing.
The incubation period runs anywhere from four days to four weeks. So a cat can be carrying it well before anything shows up.
The classic sign is a circular patch of hair loss with some scaling, usually on the face, ears, feet, or tail. But it can look like a lot of other things, and plenty of other things look like it. You cannot diagnose ringworm by eye alone. We say "suspected" for a reason.
WHY OUR CATS ARE MORE SUSCEPTIBLE
Published risk factors for ringworm include:
🔹 Being under a year old, or geriatric
🔹 Physiological stress
🔹 Malnutrition
🔹 Pregnancy or nursing
🔹 Living in high-density settings
🔹 Anything that compromises grooming or skin integrity - fleas, over-grooming, respiratory infection
Read that list again and think about a cat living in an encampment.
Young. Stressed. Often underfed. Often pregnant or nursing. Living close to a lot of other cats. Frequently dealing with fleas.
That is not bad luck. That is a list of conditions our clients' cats are living in every day.
One reassuring note: being FIV or FeLV positive does not increase ringworm risk. That is good news when you are dealing with outdoor kitties.
THE GOOD NEWS: THIS IS NOT AN EMERGENCY
Ringworm gets treated like a catastrophe and it really isn't one.
In most cases, animals spontaneously recover from ringworm within about three months. That is straight from the University of Wisconsin Shelter Medicine guidebook. Awaiting self-cure is a reasonable choice in some household situations.
Shelters treat aggressively because they need fast resolution and minimal environmental contamination. A cat living with their person in a tent is a different situation with a different calculation.
So nobody needs to panic. Nobody needs to surrender a cat over this. Nobody needs to euthanize a cat over this, ever!!!
TREATMENT OPTIONS
ORAL MEDICATION. Itraconazole is the treatment of choice. Terbinafine works similarly well. These require a veterinarian.
If a client wants to go this route, we refer them to Concern for Animals for a vet voucher, and we always recommend The Kitty Klinic - they are affordable, they are wonderful, and they are the local vet we use for OCK. For urgent situations we use Capital Pet Urgent Care. Both are locally owned, which we love.
One important note for anyone pursuing this: compounded itraconazole is not recommended. It has repeatedly been shown to be less effective and can lead to treatment failure. Ask for a generic or the brand-name liquid.
LIME SULFUR - AND WE CAN PROVIDE THIS. 🧡
This is the most effective topical treatment available, and it is something we can get directly into a client's hands.
Despite being called a "dip," you do not dip the cat. Physically dipping cats is not recommended, it is stressful and it spreads spores between animals.
Instead:
✅ Mix 8 ounces per gallon of warm water. Note: this is twice the concentration on the bottle.
✅ Do not pre-wet the cat
✅ Sponge or spray it on, making sure the coat and skin are fully saturated
✅ Use a small rag for the face, nose, and ears
✅ Do not rinse it off
✅ Wrap in a towel and let the cat dry somewhere warm
✅ Repeat twice weekly, spacing applications three to four days apart
It is safe for pregnant and nursing cats, and for kittens over two to three weeks old.
Fair warning: it smells terrible (sulfur! eww!) and it will stain things. Come prepared.
HOW YOU KNOW IT IS WORKING
A Wood's lamp - a UV light at a specific wavelength - makes a metabolite of M. canis glow bright green along the hair shaft.
Here is the useful part for tracking progress: as a cat heals, the new hair growing out of the follicle is normal and does not fluoresce. So over time you see hairs that glow only at the tips.
That is what recovery looks like under the light.
IMPORTANT THING TO KNOW: PEOPLE CAN GET IT TOO!
Ringworm is zoonotic - that means it is transmissible between animal and human. It usually shows up as a round, scaly, sometimes itchy patch on the skin, and it is treatable with over-the-counter antifungal cream from any pharmacy.
Wash your hands after handling an affected cat. If you develop a suspicious patch, see a doctor. It is not dangerous, just annoying.
SO - THREE KITTIES, THREE CONVERSATIONS
That is where we are. We will talk with each client about what they want to do, provide lime sulfur to whoever wants it, and connect anyone who wants oral meds to a voucher and an appointment.
No judgment, no pressure, no panic. Just information and options, same as always. 🐾
📖 Source: Ringworm guidebook, Shelter Medicine Programs at the University of Wisconsin and UC Davis, updated February 2026.
Feral Cat Spay/Neuter Project