I'm concerned about ticks and want to treat some of my outdoor gear with Permethrin, a spray-on very persistent treatment against ticks and mosquitoes, to reduce the chances that I'll bring home ticks from mountain biking and hiking. However, I know that Permethrin is very toxic to cats.

Is Permethrin relatively safe around cats after it has dried on your gear after initial application? My cat does have a habit of trying to sleep on my pile of dirty clothes sometimes. Would it be dangerous for my cat to be exposed to my sweaty dirty laundry after a hike, or do I need to keep him completely segregated from gear previously treated with Permethrin?

  • For an alternate strategy, I Googled: Does 20 minutes in the dryer kill ticks and found this article, which says: "And there’s one sure-fire way to kill any ticks that might have hitched a ride on your clothing. Throw any potential tick-bearing clothes in the dryer and run it on high heat for 10 minutes." This is dangerous for your cat only if he tends to sneak into the washer or dryer.
    – ab2
    Commented Mar 28, 2017 at 19:26
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    This is on topic here at Great Outdoors. It might be more on topic at Pets.
    – cobaltduck
    Commented Mar 28, 2017 at 20:22
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    @ab2 I don't understand how that would prevent tick- or mosquitobites during the trip - which is with what permethrin treatment helps. Commented Mar 29, 2017 at 8:15
  • It doesn't. But the clothing protects you against ticks and mosquitoes, especially if you spray the cuffs with Deet. then throw the clothes in the dryer, and kill the ticks that have hitch-hiked back on your clothing.
    – ab2
    Commented Mar 29, 2017 at 10:24
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    Benzo, I added (and deleted) some links to an answer. The articles are long and emphasize all the dangers of permethrin to cats, but you only asked if it was safe after the gear/clothes, etc. were dry. @James Jenkins kindly read them, and pointed out that I didn't focus enough on the question. That's a big mistake, and I'm sorry! My vets don't use it in any amount or circumstance, because they've seen too many poisoned cats. They didn't write the articles though, so they're not official! I promise to pay more attention to your wording in the future! Commented Jul 26, 2019 at 21:36

3 Answers 3


It looks like the answer is yes it is safe after it drys,

Do not expose cats to wet permethrin as it affects their central nervous system. This is not true with dogs, horses, or cows. Cats can be around permethrin treated fabrics once the application has dried.


If a product containing permethrin is applied to a dog and there are cats in the household extra care and caution should be taken to ensure that the cats do not come into contact with the product. The best advice is to apply the product in the evening, separate the dog from the cats, and allow the product to dry over night. Once the product has dried it is no longer a danger to cats or children.


Before spraying any foliage, flowers, fruits or vegetables in your yard with permethrin, bring cats inside and close the windows to the rooms where they are. Speak with your neighbors to let them know when and where you'll be spraying the permethrin so they can keep their cats indoors as well. Keep cats out of the area by covering sprayed plants with garden netting. You can remove the netting once the spray dries, usually overnight, so don't worry about the netting being a permanent fixture. Once the leaves of the plants are dry, it's safe for kitties to come out again.


For households with dogs and cats, either use spot-on products that do not contain permethrin to avoid accidental exposure, or keep the pets apart until the dog’s treatment has dried. This prevents mutual grooming or even the pets sleeping next to each other, which could result in poisoning if your cat became exposed.


Keep your cat separate from any dogs that have been treated for 12-24 hours. This allows the product to dry thoroughly. When in doubt, a t-shirt can be applied to your dog to prevent accidental exposure to your cat until the product is dried.


Keep your cat away from any areas (indoors and out) that have been treated with a pyrethrin or pyrethroid product until it has completely dried.

Pyrethrin/Pyrethroid Poisoning in Cats

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    The biggest remaining concern seems to be whether it's safe if the gear gets wet again, like saturated in sweat or water. Seems like that's not an issue, but haven't been able to find anything addressing that directly.
    – Benzo
    Commented Mar 28, 2017 at 19:08
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    Though, the source links and quotes provided are great. Thanks for the attention to detail!
    – Benzo
    Commented Mar 28, 2017 at 19:09
  • Hi Charlie! The page from your fourth link, which goes to the Cat Friendly Homes website, has moved. The quote's still on their website, but is now here. I'm hoping you might want to change that link so future viewers can learn more, and put this in context. That article is long and there is a lot of other excellent information on that site. Thanks! Commented Jul 26, 2019 at 20:08

It is not safe for cats! I have strays that sleep on my porch and I treated a hammock with diluted aerosole permethrin and caught a cat brushing on it and shood him off. A day later I found him laying dead under the porch, poor lil feller. I wish I had known and I would have at least put him out of his misery considering the nerve pain.

  • Welcome plebbin! I'm so sorry about your horrible experience! My vet doesn't use permethrin at all, including on clothing which can be kept dry or hidden away from animals. In her many years of experience, she has seen too many examples such as yours, and considers it more toxic than much of the research suggests, especially where cats are concerned. Sometimes their nervous system can't handle even a small amount. Thank you for this answer. I hope you stay and enjoy our site! Commented Jun 22, 2019 at 3:26
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    @plebbin - Was the hammock dry when the cat rubbed against it? or was it still moist from application.
    – Benzo
    Commented Jun 26, 2019 at 18:15
  • @JJJ, can you please provide some references? I'm concerned that your statement that permethrin is "used as a medication" could be interpreted to say that it is safe for cats. Product information and toxicology studies state that permethrin must not be applied topically to cats for pest control, whereas it can be used for other animals, such as dogs.
    – BalooRM
    Commented May 24, 2021 at 1:44
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    @BalooRM yea, in hindsight I don't think I meant to say that it's used as cat medicine. As I said, I googled it and found some references to sprays and creams, probably for other animals and humans. I'll remove the comment, thanks for pointing out.
    – JJJ
    Commented May 24, 2021 at 1:55


I read that it was safe when dry or when used in small amounts or all kinds of BS that lead me to believe it was okay to use as long as I was cautious. And as an overly cautious cat dad ... I knew I'd be okay based on what I read.

Fast forward three weeks. I noticed that my cat is twitching a lot. I thought from mites or fleas still, hense the need for the Permethrin). Well I also noticed that at night she was very agitated. And seemed to not be able to sit still or stop her tail from swinging. Then came the tremors. So I went to my vet and tell her what's up and whatnot thought the issue was originally (fleas/mites) and how I treated the house. Her face .... Her face told me everything. I could tell she was about to tell me something that was going to make me feel like a real a horrible pet parent. And she did. My cat will deal with this for life. It's very similar to feline hyperplasia. It's so sad and I will never forgive my stupidity. So please just don't risk it.

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    I am sorry for situation, and your cat. But as the top answer here has references saying it is safe, you can best help other cat parents by finding references that support the danger. Maybe your vet can help locate good references? Commented Jul 23, 2019 at 17:30
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    How did you cat come in contact with the Permethrin? Did you apply to your clothing / gear or to the cat to fight fleas/mites?
    – Benzo
    Commented Jul 23, 2019 at 23:17
  • Welcome Stephen! I'm so sorry for what happened to your cat. Owner's guilt is an intense burden. A dear friend with 3 dogs and 3 cats got their treatments confused. The dogs survived but within an hour all three cats had perished. I hope you'll realize you were doing the best you could. None of my vets use Permethrin on any animals, clothes, or garden products. I hope you don't mind, I added sources to your answer that were provided by my vet. If I've overstepped my bounds, please delete what I added, and accept my apology! Commented Jul 26, 2019 at 1:06
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    @sue, none of the reference you added support the answers assertion of danger when dry, in fact some of them imply it is safe when dry and or low doses Your best bet is to separate your dog from your cat until the flea-tick product is completely dry. and this one The low concentration products approved for cats contain 0.05-0.1% of permethrin Commented Jul 26, 2019 at 12:36
  • @JamesJenkins, Thank you for reading my source links (which I deleted) and for your comment! I took a broader view, ignored the specific question and probably confused a new user, all of which are bad! None of my vets use or recommend it in any level or circumstance because they've seen so many poisoned cats. They didn't write my source articles, though, and many do suggest a safe level for cats after the clothes/gear have been dried for at least a day or two. Please accept my gratitude and apology! Thanks! Commented Jul 26, 2019 at 21:19

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