Two Easy Ways to Start Earning Rewards!
Become a member today!
Members-only pricing and offers, personalized care notifications, Vital Care points back on every purchase and more!
Already a member? Sign in
Become a credit card member today!
Earn 2X Pals Rewards points at Petco
when you use Petco Pay!
APPLY NOW
Learn More About Petco Pay Benefits

My cat threw up after Sentry flea treatment. Is it dangerous?

Updated on September 23rd, 2025

Pet's info: Cat | Siamese | Male | neutered

Good evening, my wife and I applied Sentry PurrScriptions flea and tick medicine to our three cats, within minutes two of them had thrown up. We didn't see them lick themselves but it's quite possible they could have. After googling it I was scared by countless horror stories caused by Sentry. The cats are acting normally, but I just wanted to double check.

3 Answers

Most Helpful Answer

Answered By Dr. Strydom, DVM

Veterinarian

Published on December 29th, 2017

Yes, Sentry products are not recommended. If you need flea prevention you should get it from your vet.

My recommendation would be to try and wash off that medication ASAP. Use Dawn dishsoap to wash the cats since it will cut through the oils in the skin. Be sure to rinse them thoroughly and dry them with towels (not hair dryers).

If they start showing any other symptoms, especially neurologic symptoms, they need to get to a vet as an emergency.

Hope this helps. Sorry this happened. Best wishes.

1Pet Parents found this answer helpful

Related Answers from Veterinarians

Answered By Dr. Strydom, DVM
Veterinarian
Published on July 19th, 2018
Hello, thank you for using PetCoach. He is probably having a reaction to the Sentry. This is not the best product and I strongly recommend you stay away from using it. This product is known to have a high rate of reactions.

If you are looking for an over the counter product I would use Advantage II but honestly, when a cat has other underlying health issues it is best to consult with your vet as to what the best product would be to use for him.
At this point in time, the best thing to do is to bathe him in Dawn dish soap in an attempt to remove any residue from the Sentry and then wait two weeks before applying a different product.

Hope this helps. Best wishes.
1Pet Parents found this answer helpful
Answered By Dr. Melanie, BVSc MS
Veterinarian
Published on March 27th, 2020
Thank you for contacting Petco Pet Education Center, formerly Petcoach with your question about Samantha. Sentry is actually a pretty good product, it's one that I recommend, and I would not worry about reviews online. That is anecdotal evidence not scientific evidence. She should be ok. I hope this helps!
1Pet Parents found this answer helpful

Smart Picks for Smart Questions

Related Questions

Health & Wellness

My cat threw up after topical flea medicine. Is this normal?

No, this is not normal. You did not say which product you used. Some are more likely to cause reactions than others (like Hartz or Seargants). I suggest you use some Dawn dishsoap and wash it all off of him immediately.

Updated on September 23rd, 2025

Health & Wellness

My cat has fleas, Sentry failed. What's a fast, safe flea treatment?

Over the counter Hartz and Sentry products do not work. I suggest you get prescription strength flea medications. You can easily get these medications from one of our VETCO clinics inside Petco stores. Here are the ones in your area: ( https://www.vetcoclinics.com/services-and-clinics/clinic-locations-and-schedules/?zip=77081 ) Take the cats with you. It is first come, first serve and there is no exam fee so just the cost of the products. The vet there can advise you when you can give the new product based on when you applied the other product. You also need to treat your house and yard (if you have one for fleas). I suggest these products: ( https://www.allivet.com/p-1389-knockout-es-area-treatment.aspx ) ( https://www.allivet.com/p-9065-vet-kem-yard-spray-32-oz.aspx?SearchTerm=yard%20spray+Auto ) Hope this helps. Best wishes.

Updated on September 23rd, 2025

Health & Wellness

My cat licked Sentry PurrScriptions flea treatment. Is it safe?

Every medication that has an effect also can have a side effect. Considering many millions of pets are being treated with this preventative, but only few have serious side effects, you should not worry. Here is reliable information: https://www.drugs.com/vet/sentry-purrscriptions-plus-squeeze-on-for-cats-and-kittens-over-5-lbs.html According to this there are sometimes local reactions (skin reactions) If your kitty's skin in the application area looks normal or at worst slightly pinker than the surrounding skin, then she does not have an untowards reaction. She is going to be alright.

Updated on September 23rd, 2025

My cats are sick after flea spray. Could it be permethrin poisoning?

If your cats are showing signs of poisoning, this is a medical emergency and they need veterinary treatment now. There is nothing you can do at home for them, as cats are very sensitive to flea treatments and any time they show signs of poisoning, veterinary treatment should be sought right away. Please take them into an ER vet clinic; if there isn't one in your area, there will be a vet on call for emergencies. The information to reach that vet is found on a clinic's answering machine or website.

Updated on September 23rd, 2025

My cat is twitching after flea treatment. Should I be concerned?

Yes I would be concerned, as this can be a sign of flea treatment toxicity. I would put her into a bath immediately, and gently wash the treatment off with water water and Dawn dish soap. Continue to monitor her for signs of toxicity, including vomiting, diarrhea, muscle tremors, hyper salivation, and depression. If you see any of those signs, take her into your vet immediately. I would make sure that the flea treatment you put on Annie was for cats and not for dogs, as it's very important to have a cat dose for cats because they are so sensitive to the flea medication. I would wait a few days before reapplying a flea treatment, and I would use a different brand than what you just used. I recommend using Advantage or Revolution.

Updated on September 23rd, 2025

I accidentally put dog flea medicine on my cat. Will she be okay?

Cats are exquisitely sensitive to flea treatments, so there is a potential this could cause problems in Monty. I would wash him off thoroughly with warm water and Dawn dish soap. Watch him for signs of toxicity which include excessive salivation, paw flicking, ear twitching, vomiting, diarrhea, depression, incoordination, and muscle tremors. If you see any of those, rush Monty into a vet immediately.

Updated on September 23rd, 2025

My cat threw up after flea treatment. When should I see a vet?

If the vomiting becomes a regular thing at least 3 times a week, you should take her to the vet in order to get it checked. it could be the flea spray that you used for the house, it's not likely to be the frontline though. it could also be something totally unrelated and just a coincidence.

Updated on September 23rd, 2025

Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Share