K9 ADVANTIX II Flea & Tick Spot Treatment for Dogs, over 55 lbs, 2 Doses (2-mos. supply) - Chewy.com

K9 Advantix II Flea & Tick Spot Treatment for Dogs, over 55 lbs

By K9 Advantix II
Rated 4.212 out of 5 stars

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About This Item


  • Broad-spectrum, veterinarian-recommended treatment repels and kills fleas, ticks and mosquitoes on dogs 7 weeks or older and weighing 55 pounds or more.
  • Begins working within 12 hours and kills pests on contact.
  • Kills all life stages of fleas to prevent re-infestation; also kills lice and even repels biting flies.
  • Waterproof formula continues working for up to four weeks, even after bathing or swimming.
  • Convenient, monthly topical application contains imidacloprid, permethrin and pyriproxyfen; available in packs of 2, 4 or 6 treatments.

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Play Video: Learn More About K9 Advantix II From Our Team of Experts
Learn More About K9 Advantix II From Our Team of Experts

Important Information

Fleas rise to the top of your pet's coat as they die, so consider it a triumph if you start seeing more fleas at first, after treating your pet. If you’re still seeing fleas after application, it may be because your pet has picked up new fleas from the environment, which may include other pets, surfaces and outdoor areas. It may take up to 30 days to break the entire flea life cycle. Additionally, you should also treat sources of new fleas (i.e., carpet, yard, etc.) to ensure complete flea control.

About K9 Advantix II

Experience the Advantages of K9 Advantix II

Veterinarian-recommended K9 Advantix II kills fleas, ticks, mosquitoes and lice, and repels biting flies. Now you can help your dog fight these pesky pests through contact—no biting required. Convenient and easy to use, K9 Advantix II is for dogs and puppies 7 weeks of age or older. So help your pal get the effective protection he needs with all of the advantages of K9 Advantix II.

Why are Biting Bugs a Big Deal?

K9 Advantix II spreads over the skin and hair to kill and repel them through contact, meaning they do not have to bite to die. And if a flea, tick or mosquito is repelled, it cannot bite and transmit disease.

Why Choose K9 Advantix II?

Fleas, ticks and mosquitoes can negatively affect your pet's health. It's important to use an effective product that kills pests which can spread disease. Fleas can cause flea allergy dermatitis, an allergic reaction that can lead to constant scratching, severe itching and even hair loss. Ticks can transmit deadly diseases, such as Lyme disease and Rocky Mountain spotted fever. And mosquitoes can potentially carry dangerous diseases, too, including heartworm. K9 Advantix II should not be used in place of a heartworm disease prevention product.

Is K9 Advantix II the Right Choice for Your Dog?

Whether your dog is a winter snow hound or a summer backyard explorer, an sunseeker or an outdoor enthusiast, choose K9 Advantix II to help keep fleas, ticks and mosquitoes from interrupting his favorite activities year-round. If you want to return the love to your dog, take care of him with flea prevention that works to kill the fleas you see and the ones you don't.

K9 Advantix II Has a Treatment for Dogs Large and Small


4-10 pounds


11-20 pounds


21-55 pounds


55 pounds and over

Do not use K9 Advantix II on cats.

About K9 Advantix II

K9 Advantix II is manufactured by Bayer, a leading name in the healthcare industry for over 150 years. K9 Advantix II is a monthly flea, tick and mosquito treatment for your dog that kills through contact—no biting required. It starts working to kill fleas within 12 hours of application and is veterinarian recommended, so you can feel confident knowing that your pet is getting effective protection.
Shop Bayer

Questions & Answers

31 Customer Questions

Where is the manufacturer date on the box?

Will Advanix kill Heartworms as will as Flea's and Ticks
Answer by ChewyJun 02, 2021
This treatment is specifically formulated to repel and kill fleas, ticks and mosquitoes. It kills all life stages of fleas to prevent re-infestation and also kills lice and repels biting flies.

Can this product be used on pregnant dogs?
Answer by ChewyMay 21, 2018
K9 Advantix II is suitable for use with a pregnant or lactating dog.

Can I use both this along with the collar flea preventer?
Answer by ChewyAug 15, 2018
We encourage speaking with your Veterinarian before combining supplements, for the safest opinion.

ReviewsWrite a Review

Rated 4.212 out of 5 stars
1693 Reviews
Would recommend to a friend

1693 Customer Reviews

Filter by reviews that mention

Always consult a veterinarian about your pet’s health needs. Customer reviews should not be used as medical advice.
Rated 5 out of 5 stars
By onedef92 on Mar 12, 2023

Protect your pet with K9 Advantix II

Don't go with the budget brands, never found one that works half as well as this stuff. Ask your vet, if you get the dosage correct for some of this you can treat two small dogs using one large dog treatment (but ask your vet first!)

Rated 2 out of 5 stars
By StillaStruggle on Feb 27, 2023

No Good Results

I've had my dog on this for three months and have yet to see any good results. She's still being bit up by bugs outside I have two more doses left and don't think I should use them. Guess I should've thought twice before buying five...

Rated 5 out of 5 stars
By Rena on Mar 24, 2023

Economical and Effective

Provides protection for my pets at a reasonable price. I have been using it for years with no issues with fleas or ticks.

Rated 5 out of 5 stars
By oek9mom on Dec 29, 2022

So far, So good!

I'd always been a fan of the Seresto collars & had used them for years successfully but apparently something happened a couple of years ago & I've had two bad experiences with them. I'd used K9 Advantix previously & went back to it. So far, so good! Thank you!

Rated 5 out of 5 stars
By Rombo62 on Mar 5, 2023

Excellent Product

I've used this for my last dog and again on my current. It works as advertised and I prefer topical over a pill.

Rated 1 out of 5 stars
By LoriA on Mar 16, 2023

Made my dogs back all flaky

My dogs back is still flaky along the line where I administered the meds. And it's been 4 days.

Rated 1 out of 5 stars
By Cindy on Feb 13, 2023

Be Careful

Our dog had a reaction to this flea and tick medicine. Caused Skin irritation and made him itchy and irritable.

Rated 5 out of 5 stars
By Polly on Mar 26, 2023

Great Deal

Chewy always delivers my orders expediently. Good deal on flea/tick med.

Rated 5 out of 5 stars
By Roxiemom on Nov 18, 2022

Does just what it says

My first use greatly decreased the problem when dog was brand new to me. Repeated in three weeks and then monthly as indicated. I haven't had any problems with fleas, ticks, mosquitos. No skin allergies either. My backyard is within 30 feet of deep drainage creek too.

Rated 5 out of 5 stars
By TSquared13 on Feb 4, 2023


Best flea, tick AND mosquito defense available on the market. The application is easy to apply and works!