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

Can I apply Frontline to my cat a week after Sergeant flea treatment?

Updated on September 23rd, 2025

is it safe for my cats to apply frontline after using sergeant's silver about a week ago, like, they have totally different ingredients, are they going to interact and harm my cats?

2 Answers

Most Helpful Answer

Answered By Jenny, DVM

Veterinarian

Published on July 25th, 2017

Cats can be sensitive to flea medications. For that reason it is safest to wait 2 weeks between products even with different ingredients. Your vet can prescribe a cap star which is a pill that will last for a day that can help while you wait the remaining time

1Pet Parents found this answer helpful

Related Answers from Veterinarians

Answered By Linda G, MS, DVM
Veterinarian
Published on October 11th, 2017
Hello, & thank you for using Petco Pet Education Center, formerly Petcoach. I would wait at least another 2 weeks before using another topical. In the meantime, you can definitely use one of the oral cat flea products. You can purchase Capstar in most bigger pet stores. It only lasts 24 hours, but you can administer it several times a week until you can use another topical ( I recommend either Frontline Gold, or Bravecto for cats ). Or you can purchase Comfortis from your veterinarian. With this, 1 pill will last 30 days. I like Revolution, more because it gets heartworms plus hookworms & roundworms, but it is a topical, too. So use an oral tablet for now. They work great. Take care.
1Pet Parents found this answer helpful

Smart Picks for Smart Questions

Related Questions

Cat's flea treatment not working. Can I safely apply Frontline now?

Since both Sentry and Frontline use the same active ingredient (fipronil) it is unlikely that you will see better protection switching to the Frontline. You will need to choose a product with a different ingredient, like Advantage or Revolution or a Seresto collar. If you choose to use another topical, I would recommend bathing your kitty today to remove any remnants of the Sentry, and wait 3 days to apply the next topical. It is important to wait after bathing so that the natural body oils have time to coat the skin to ensure adequate absorption. You do not need to wait or bathe to use a Seresto collar.

Updated on September 23rd, 2025

My cat had Advantage, but I washed it off. Can I apply Frontline?

The two treatments are not closely related but I would still recommend 7-10days before reapplying. You do not mention why you washed off the advantage but I would recommend combing with a flea comb to remove fleas in the meantime if still present. It may be worth considering using comfortis or capstar tablets if he does not tolerate spot on medications (it is often the carrier and not the active ingredient that pets are sensitive to)

Updated on September 23rd, 2025

Can I use Seresto collar on my cat right after Frontline Plus?

Cats are exquisitely sensitive to flea medication, so I would not put the Seresto collar on Willow just yet. Wait at least two weeks, then apply it. You can give her Capstar now. It’s a one time pill that starts killing fleas and is safe to give. I hope this helps!

Updated on September 23rd, 2025

Health & Wellness

My cat got underdosed Frontline. Can I reapply safely for fleas?

Yes it is safe to reapply most topical flea preventatives every 2 weeks if needed. This should be fine and safe to do since you are 2 weeks out. However, if you are still seeing fleas after this correct dosing, it is best to consider switching to a more effective product such as Revolution. Best of luck with your cats moving forward and keeping the fleas away. Take care.

Updated on September 23rd, 2025

How soon can I use Frontline for cats after Zodiac spot-on?

Hello, & thank you for using Petco Pet Education Center, formerly Petcoach. You can apply the frontline 3 weeks after using the zodiac. If you need to use something quicker, you can administer an OTC Capstar immediately, or purchase a Comfortis from your veterinarian.

Updated on September 23rd, 2025

Health & Wellness

How soon can I apply Advantage II to my cat after another flea med?

If it's been at least two weeks since you applied the Sergeant's, which it has been, it's safe to apply the Advantage now. You will also have to disinfect the environment. Wash their bedding in hot soapy water, and vacuum the furniture and carpet surfaces. You can use a spray to kill fleas in the house, such as Indorex, or a flea bomb would work well to kill the fleas in the home.

Updated on September 23rd, 2025

Health & Wellness

How long should I wait to use a flea collar after cat flea spray?

I would not recommend repeating treatment with similar ingredients for at least a month, especially in cats which are very sensitive to overdosing. It is important to treat bedding and sleeping areas to kill eggs and larvae before they hatch. If problems persist contact your vet for oral treatment such as comfortis

Updated on September 23rd, 2025

Have A Vet Question?

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

Share