Ringworm in foster homes

Several people have contacted me for ringworm advice. I'm starting this page to document what I've noticed and learned, as well as what has worked best for me and/or LAPS. I'm NOT a vet, so please check with your vet before starting any treatment!


  • Ringworm is a fungus, not a worm. It is zoonotic, meaning it is highly contagious to humans, cats, and dogs. Ringworm spores can survive in your carpeting or house for 18+ months.
  • If someone you know is battling ringworm with their kittens, they will probably need a hug, kleenex, and lots of wine. It's pretty daunting, especially at first.


  • Infected animals should be isolated as soon as ringworm is suspected - bathrooms are ideal because they are easier to disinfect. Carpet is not advised.
  • We start treatment as soon as ringworm is strongly suspected, because waiting up to 2 weeks for the results of a Fungassay culture would result in a disastrous number of spores being released into the environment + further delay in clearing the animal for adoption.
  • Anything that has been in contact with the infected animal must be disinfected or discarded.
  • Any animal or human that has been exposed should be dipped/bathed and inspected for lesions until the animals with ringworm test negative.


  • There is a new PCR test for ringworm that is very sensitive and will have results within 1-3 days. It can also identify the species of ringworm, which is helpful. For example, Trichophyton generally takes longer to return a positive result using a Fungassay, so if you know it's Trichophyton, you want to make sure you don't assume a Fungassay is negative after 14 days.
  • There isn't a lot of information about the PCR test for ringworm because it's so new, but I believe it will return a positive if your animal has picked up a spore from the environment, or if there is a dead spore remaining on the animal, in which case your animal might be culture negative, but still get a positive result. PCR is a great way to diagnose, but I would use a Fungassay for at least one of the negatives when you are trying to confirm the animal is cured of the infection.


  • The best way to treat ringworm in a shelter/fostering context is Itraconazole + 2 anti-fungal baths/week, combined with stringent ongoing environmental decontamination. I should reiterate I am NOT a vet, so please confirm any treatment with your vet!
    • Unless a cat or kitten has other health issues, we go with a dosage of 10mg/kg Itraconazole. Itrafungol is the best form of Itraconazole, as many factors can diminish the effectiveness of compounded Itraconazole. Itraconazole should be taken with food to aid absorption.
    • In general, Itraconazole is given once daily for 28 days, then pulsed one week on, one week off, until two consecutive negative Fungassays.
    • It is important to monitor cats/kittens getting Itraconazole for signs of liver problems and contact your vet if you see any of these: lethargy, apetite loss, vomiting, diarrhea.
    • According to the most recent studies we could find, Duoxo Chlorhexidine Climazole shampoo is more effective than lime sulphur dips. We haven't tried it yet.
  • Creams are minimally helpful, as they are licked off before they can have any effect. They certainly don't hurt, but we don't spend the extra money.


  • Bleach at a 1:10 dilution is one of the only ways to kill ringworm spores.
  • Your new daily cleaning ritual (you may want a glass of wine in hand before you read this):
    • Put kittens in a crate or disinfectable holding area. I put mine in the tub in the bathroom, then disinfected the room, put the kittens back in the clean room, then disinfected the tub for next time.
    • Throw away disposable items
    • Put bleachable items like bedding in a garbage bag or bin to be soaked in 1:10 bleach solution for 10 minutes, then washed/dried on your hottest setting
    • Vacuum thoroughly. Be aware that this will contaminate your vacuum. Some people advise buying a cheap vacuum and then throwing it out when the ringworm is cured.
    • Every surface must be clean and free of debris in order to be effectively disinfected.
    • Mop hard surfaces with 1:10 bleach, Peroxigard or Virkon, and keep them wet for 10 minutes to kill spores. Be aware that Peroxigard will eventually melt the paint off your baseboards if they're wood. I learned this the hard way. Test whatever you're using on your floor to make sure you're not going to ruin your floor.
    • Dump litter, disinfect litterboxes when you're doing your floor mopping.
    • Disinfect any plastic beds, bowls and plastic toys.
    • After 10 minutes, rinse the floor and dry it so your kittens aren't burning their toesies and licking chemicals off themselves.
    • Wash food/water bowls with hot water and dish soap.
    • Give them clean bedding, food/water bowls, litterboxes/litter, toys, new boxes to play in, etc.
    • Take the garbage out, or it will pile up like mine did, and then you'll be even more overwhelmed.
    • Throw a load of laundry in, since this will pile up fast too.


  • LAPS staff glove + gown EVERY time they enter the iso room. I was wearing clean scrubs + socks or shoes every time, but instead of gloves, I dipped my hands in peroxigard solution (similar to bleach). Gloves are definitely the safest route. Keep a bin outside the door and peel scrubs off and put them in the bin to be soaked in bleach and washed
  • I use a litterbox with a towel folded in the bottom soaked with Peroxigard (or bleach solution, if it won't ruin your floor if it splashes out) outside the door to step in to disinfect bottom of feet OR take off socks without stepping back in the contaminated room. It's tricky, but the goal is to not touch anything on the outside with anything that's touched anything on the inside.
  • Keep a spray bottle with 1:10 bleach in it to spray your hands, doorknobs, and anything you accidentally step on or touch.
  • Block off the door crack if you have other animals around - you don't want them playing pawsies with each other under the door.


  • Ask for help! This is a tough one for some of us fosters, but once you do it once or twice, it gets easier. ;)
  • Take a break
    • Call your shelter
      • If you're fostering through a shelter, tell them you need a break. They should be able to find space for you at the shelter, or with a staff member or another foster.
      • MAKE SURE whoever takes them knows how to follow proper containment protocol
    • Call a local shelter
      • Many shelters immediately euthanize animals with ringworm, so MAKE SURE you only take them to a no-kill facility that is equipped to handle ringworm.
    • Vent to your internet friends :)
      • It's a safe bet most of us kittencam moms & dads have been through ringworm or something similarly discouraging. Send us a message, and we'll listen to your venting and help however we can.
      • Join one of our chats, and vent to the awesome group of people who support us. They'll support you too, because they're just that awesome.
  • These are some of the fosters/chatters you can commiserate with:
  • I've found it difficult to explain to some friends and family why I'm not responding to texts for weeks at a time without them rolling their eyes and thinking I would rather "play with kittens" than spend time with them. Perhaps if you send them this link, they'll understand a little better. And then maybe they'll drop off soup and some old towels. ;)


I've also been asked how people can support other fosters who are dealing with ringworm. Here's what I found most helpful:

  • Cheap, disposable toys
  • Disposable scratching posts
  • Old towels/blankets. You would not believe how many of these I went through.
  • Bleach or Peroxigard
  • Paper towels
  • Large black garbage bags
  • Peroxigard wipes
  • Cardboard boxes
  • Plastic bowls for the kittens to sleep in
  • Plastic beds that can be lined with towels and disinfected daily
  • Cat litter - went through a ton of this too
  • Wood's lamp - only 50% of rw will fluoresce, so don't rely on this
  • Replacing cat trees and other expensive items that were contaminated and need to be thrown out
  • Cleaning/laundry help
  • Money for Itraconazole ($160/bottle, depending on which one you're using)
  • A fungassay is about $45, a PCR test is about $50, not including any vet fees. Each animal will need a minimum of three, more realistically four or five. The Jungle kittens needed a whopping 46 tests done.
  • Wine / meals - there's no time for shopping or cooking
  • Hugs & kleenex
  • Hand lotion to combat Grotesque Zombie Hand Syndrome from the harsh chemicals


  • Based on our experience, ringworm is generally resolved when there are no new lesions appearing and hair starts growing back where lesions were.
  • The minimum time to cure is thought to be 42 days.
  • As soon as you see hair regrowth, or you think your cat is clear, get a Fungassay or a PCR test to confirm. Continue to treat them as if they were positive until you get a negative result. Repeat tests until you get two consecutive negatives. More on this later.
  • You can take samples from your environment and get a PCR test done to determine if your home/shelter's iso room has been disinfected effectively.