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

By K9 Advantix II
Rated 4.3136 out of 5 stars
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K9 Advantix II Flea & Tick Spot Treatment for Dogs, over 55 lbs, 1 Dose (1-mo. supply) slide 1 of 10
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K9 Advantix II Flea & Tick Spot Treatment for Dogs, over 55 lbs, 1 Dose (1-mo. supply) slide 1 of 10

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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 8.80%, Permethrin 44.00%, Pyriproxyfen 0.44%....Active Ingredients: Imidacloprid 8.80%, Permethrin 44.00%, Pyriproxyfen 0.44%....Permethrin: 45%, S-Methoprene: 3%, Other Ingredients: 52%.
LifestageAdultAdult, Puppy, SeniorAdult, Puppy, SeniorAdult, Puppy, SeniorAdult
Breed SizeLarge Breeds, Giant BreedsSmall Breeds, Medium BreedsSmall BreedsExtra Small BreedsLarge Breeds, Giant Breeds

Questions & Answers

35 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.

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

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.

ReviewsWrite a Review

Rated 4.3136 out of 5 stars
1607 Reviews
Would recommend to a friend

1607 Customer Reviews

Filter by reviews that mention

Rated 5 out of 5 stars
By rescuemom 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 1 out of 5 stars
By DaMoose on Oct 1, 2022

Not Affective!

This is the result of just one swipe of a flea comb down my dogs back! I applied this product on September 1 and again on September 22. As you can see, it’s not affective! Granted it’s not all fleas but if you zoom in you can see a lot of it are fleas! I have also sprayed the yard twice, the indoors three or four times and it’s just her that has the fleas. My cat is wearing a very well known flea collar and she has no fleas! The flea collar is very expensive but if it works, you can’t put a price on it.

Rated 5 out of 5 stars
By greatpyrmom22 on Nov 17, 2022

Totally Dependable Product

I have used K9 Advantix II since 2007, when I could only get it through my veterinarian. So, for the past 15 years, I have depended on this product for my large & giant-breed dogs. K9 Advantix II never failed us even once!

Rated 5 out of 5 stars
By Cathy on Nov 11, 2022

Flea meds advantage good

Good flea meds better than Frontline as far as I am concerned. Seemed to work for my dogs than Frontline did. Would recommend advantage first. It stopped their itching and scratch allot better. Worked faster and lasted longer

Rated 2 out of 5 stars
By Patty on Nov 14, 2022

Flea season

I ordered as soon as I saw my animals had fleas. I am allergic to fleas so I needed for them to be gone fast. I use this product alot and this is the 2nd time it hasn't worked at all. I am so upset.

Rated 1 out of 5 stars
By Sarah on Oct 1, 2022

Does not work on fleas

K9 advantix and seresto collars have both failed to kill any of the fleas on our dogs this season. We have used both for years without fail, seresto during the summer and k9 advantix for the other seasons,but now that they are owned by a new company neither work at all. Do not waste your money on either of these products.

Rated 5 out of 5 stars
By MackLowe1 on Aug 12, 2022

Only one worth getting

My family and I habe been using this EXACT treatment for our labs for over 20 years and this is the only one proven effective towards ticks!!! Fleas don't stand a chance to any topical treatment in my opinion, but this is the only collar or topical I can find that will hold up against ticks.... my dog is 8 and has never had a tick on her, we walk thru our country fields every night and habe never had a problem!! Recommend 1000 times over!!

Rated 5 out of 5 stars
By boemund on Nov 15, 2022

Thank You Chewy

My Doberman is 7 years old and from beginning we use this treatment. WE never have problem with flea or ticks.

Rated 1 out of 5 stars
By John on Aug 18, 2022

Does not kill ticks

I saw Brown Dog Ticks on my 2 dogs here in the Phoenix area of Arizona and administered this according to the instructions. 11 days later my dogs are completely infested with ticks and this did nothing to help. Maybe this product works better for different ticks or in different regions but I was very disappointed

Rated 5 out of 5 stars
By Jake on Aug 9, 2022

K9 Advantix II

Excellent product, have been using K9 Advantix for my 96 lb. Golden for years. Never had any problems with fleas or ticks. It kills them instantly. Your Customer Service Representatives are excellent when I call in my order.