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

By K9 Advantix II
Rated 4.3409 out of 5 stars
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K9 Advantix II Flea & Tick Spot Treatment for Dogs, over 55 lbs, 6 Doses (6-mos. supply) slide 1 of 9
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K9 Advantix II Flea & Tick Spot Treatment for Dogs, over 55 lbs, 6 Doses (6-mos. supply) slide 1 of 9

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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.
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

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Top IngredientsActive Ingredients: Imidacloprid 8.80%, Permethrin 44.00%, Pyriproxyfen 0.44%....Active Ingredients: Imidacloprid 8.80%, Permethrin 44.00%, Pyriproxyfen 0.44%...Active Ingredients: Imidacloprid 9.10%, Pyriproxyfen 0.46%.Active Ingredients: Imidacloprid 8.80%, Permethrin 44.00%, Pyriproxyfen 0.44%....Active Ingredients: Imidacloprid 8.80%, Permethrin 44.00%, Pyriproxyfen 0.44%....
LifestageAdultAdult, Puppy, SeniorAdultAdult, Puppy, SeniorAdult, Puppy, Senior
Breed SizeLarge Breeds, Giant BreedsSmall Breeds, Medium BreedsLarge Breeds, Giant BreedsSmall BreedsExtra Small & Toy Breeds

Questions & Answers

38 Customer Questions

Where is the manufacturer date on the box?

Do the boxes have an expiration? We have some unopened tubes from last year, still.
Answer by ChewyJul 02, 2017
This item doesn't have an expiration date, but rather a manufacturers date on the box. After two years, this item may start to lose its potency, but it doesn't expire.

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.

My dog is over 100 lbs. will this work
Answer by ChewySep 10, 2018
This treatment is for dogs that are over 55 pounds.

ReviewsWrite a Review

Rated 4.3409 out of 5 stars
1543 Reviews
Would recommend to a friend

1543 Customer Reviews

Rated 5 out of 5 stars
By Carine on May 6, 2022

The best! Skip the rest!

I use this on all my dogs. People always ask me how I have so many pets and no flea problems. Well, I use this from early spring to early winter and I use Advantage for my cats. The key is use this every month BEFORE you see fleas. Don't wait until you have a flea problem! Think of it as a preventative. Even indoor dogs need it. I hear people say "well my dog only goes out to use the bathroom" well then your dog is exposed to fleas! Fleas are outside everywhere. Trust me. They are insects. They get around.

Rated 5 out of 5 stars
By Audrey on May 5, 2022

Chewy is the best

I accidentally ordered too many of these but Chewy was kind enough to refund my order. I was afraid they would expire before I could use them but Chewy didn’t even want me to return them; they told me to donate them to a shelter. This is why we love Chewy so much! They really care about their customers and the animals. Thank you so much, Chewy! We will always continue to buy our products from you.

Rated 5 out of 5 stars
By IADale on Apr 29, 2022

Excellent Topical for Summer

I’ve used this one for several years and it keeps the pesky ticks, fleas And Mosquitoes away from our dog. Sorry; but I can’t get in the pill camp for this one yet and unlike other products, it’s aimed at killing the pests be for the bite your pet. This is a competitive cost compared to others and an easy shop to my door along with other pet meds.

Rated 5 out of 5 stars
By mekayla on Apr 4, 2022

Great product

I’ve been using this treatment for almost 4 years now on both of my dogs after having so much trouble with either other topicals, the collars, the oral chews you name it. I finally landed on this one and it’s worked 100% ever since. The only down side is it does leave a sticky spot on your dogs shoulders for a few days but after a day or two I’ll daily brush that spot very well and goes away in no time!

Rated 5 out of 5 stars
By Bubby on May 18, 2022

5 star product

I've been using this product for years, and have never had any fleas. I worked with Boxer Rescue in Oklahoma for 28 years and have used it on all of my numerous rescues. I will never use anything else.

Rated 5 out of 5 stars
By AnnDee on May 2, 2022

K9 Advantix II - IT WORKS

My previous dog had an allergy to flea bites plus we live in an area where ticks are a threat. He did much better with K9 Advantix II than he did with previous medications. I have a new dog now and I’m going to continue using this proven product.

Rated 4 out of 5 stars
By macfadden on Feb 20, 2022

Works fine, but has sticky residue that attracts dirt

My dog's been on this for 6 years. In that time he's had one tick and no fleas, so it seems to work fine, but it makes a mess. The product comes in a tube, and you squeeze it out in little puddles along the dog's spine. It is a sticky, clear liquid and you're not supposed to touch it for a few days because it's harmful to humans if absorbed through the skin. The liquid leaves greasy patches on my dog's back, which then attract dirt. On a white dog, it's very noticeable. I'm going to ask my vet about a non-topical alternative to avoid the aforementioned monthly creation of dirty, greasy patches of stuff humans shouldn't get on their skin on my dog.

Rated 5 out of 5 stars
By Mama on Apr 23, 2022

Best protection.

The best thing about K9 Advantix is unlike other flea and tick treatments K9 also repels Mosquitoes. Before I found this product, my poor puppy would get eaten alive. Now not a single bite from any bugs. Great product.

Rated 1 out of 5 stars
By Junk on May 14, 2022

Does not work

I used this on my shepard and he still got live ticks on him so 2 weeks later I put another on him still didn't work. I have pulled off fat live juicy ticks still alive.

Rated 5 out of 5 stars
By Abby on May 20, 2022


Always delivered timely and with care. Always trust Chewey for all needs for the 4 legged friends. From tots to meds to delicious foods it's all fantastic