K9 Advantix II Review and Comparison (2021 Edition)

In a world with so many options, it can be difficult to choose the right method of treating pesky fleas that pop up on your dog after playing outside.

We at Pest Strategies are here to give you some insight on which product may be right for you and your furry friend.

Continue reading down below for more information to decide whether K9 Advantix II is an option you should consider to rid your pet (and your home!) of those parasites.

(hint we kinda like it)

k9 advantix ii review

Rating: 97.50

Our #1 Ranked For: Termites,Bed Bugs, and Larger Infestations


Rating: 97.00

Our #1 Ranked For: Ants, Roaches, Spiders, and Rodents Issues


Rating: 95.70

Our #1 Ranked For: Mosquito Removal, Fleas, Ticks, Wasps, And Other Stinging Insects

SECTION 1: The Rating

This product is one of the most popular flea- and tick-killing products on the market.

This product has gained such popularity mainly because it just works, and dogs hardly react when it is applied to their skin.

Unlike other products, when you apply it, there are minimal side effects and results within a few hours.

When most users take advantage of this product, they are pleasantly surprised at its ease of use and efficiency in killing actual fleas.

Click here to learn more specifically about dog tick flea medicine.

Pest Strategies Rating

K9 Advantix 2 is more than just a flashy name; it stops the fleas and ticks fast without making your dog upset.

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SECTION 2: Pros and Cons

As always, a consumer needs to know the ups and downs of why a product works. Here's a quick list of the pros and cons to help you make up your mind.


  • Kills and protects against fleas, ticks, and other pests
  • Solution can withstand water and sunlight
  • Repels against mosquitoes
  • Dogs love it, therefore you can expect no biting!
  • No smell and dries within 2-3 hours
  • Gentle on your dogs body with minimal side-effects


  • Can burn the skin of smaller dogs
  • Can make dogs lethargic after application
  • Product is pricey (but still more affordable than prescription brands)
  • For extremely wooded areas, this product may not be as effective. Better suited for backyards and other minimally infested areas

SECTION 3: The Key Features

What's so special about K9 Advantix II?

We've compiled an overview for you to check out its features quickly and at a glance.

Easy to Apply

The product is contained in a small pipette which is used for application. The dog’s fur along its spine must be parted and held tightly to one side in order to allow a place for the medication to seep into the skin.

Outer-Layer Protection

The active ingredients will release through the skin of your dog and provide protection along its entire body. This medication sits on the outside layers of your dog's skin, which means that it never enters the bloodstream.

Affects the Entire Life Cycle

The serum kills parasites in all life stages on your dog, then acts as a protective shield against new fleas and ticks. Regardless of whether there are eggs hiding in your dog's coat or fully-grown fleas, this medication will knock them right out.

SECTION 4: The Review

When evaluating products, we use five criteria:

  • Company Reputation
  • Active Ingredient
  • Easy Of Use
  • Pet and Child Safety Rating
  • Overall Effectiveness

Reputable Company/Customer Service:

This product is manufactured by Bayer, which has made a name for itself as one of the most reputable pharmaceutical companies in the world.

As a result, this flea and tick medication is top-quality and name-brand, so consumers feel like the safety of their pet is in the best possible hands when they buy this product.

bayer animal health website

Bayer, a German pharmaceutical company most recognized for its aspirin, is very well-known and well-received by consumers. This applies to medications for humans as well as pets, so pet owners feel like trusting the health of their animals to this company is a good idea. 

A Note About Bayer

Because of its multinational expanse, Bayer has set its business up into subsidiary companies. The manufacturing company responsible for K9 Advantix 2 is called Bayer Animal Health.

Active Ingredient:

The two active ingredients imidacloprid and permethrin work to poison the fleas by contact within 12 hours. 

  • Imidacloprid is an insecticide that acts as an neurotoxin to insects and relatively harmless to mammals.
  • Permethrin is classified as pyrethroid, which is a man made chemical developed to be similar to another a natrually occurring insecticide called pyrethrum. Pyrethrum comes from the chrysanthemum plant, and it is highly rated in the pest control space.

Sometimes people will want to these ingredients individually because they're more affordable, but we highly recommend against such use as that is often against the label instructions and dangerous for your dog.

Ease of Use:

If your dog doesn’t squirm when held still, applying this product is a breeze.

However, if it moves around frequently, you may have a problem applying the serum evenly. Some users have reported that their dog’s skin gets burned (especially small dogs), so it’s important to pay attention to the amount of chemical you’re giving your dog and that you have purchased the right solution for your dog’s weight.

Is This Pet and Child Safe?

As long as your dog isn’t too light for the formula you’ve purchased, it will be fine.

However, this formula is not designed for cats, and can cause serious harm to a cat if exposed. This medication should be kept out of reach of children, as it can be harmful if ingested in any way.


This product is not safe for cats. If accidentally used on a cat, please call your nearest Veterinarian for instructions on what to do next.

Overall Effectiveness:

With happy, lifelong customers and a thriving place on the market, this product works well. Within 12 hours, you should see your dog stop scratching, as all ticks and fleas should be dead by that time. 

There are countless reviews across the internet with happy customers reporting continued successes against fleas using this product. The company itself has been around for years and continues to make their product better each year.

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SECTION 5: How Does It Compare Against Competitors?

So, what other options are out there, and how does this flea medication compare?

  1. Frontline Plus
  2. Capstar Flea Tablets
  3. Seresto Flea and Tick Collar

K9 Advantix II vs. Frontline Plus Tick and Flea Control

This is the most notable competitor, as Advantix and Frontline are the two biggest names on the market for flea protection for dogs. The two products work in the same way, and so the only real difference comes down to active ingredients.

K9 Advantix II uses imidacloprid and permethrin, whereas Frontline uses fipronil. A study published in 2008 tested imidacloprid and Fipronel and found that they were both effective, but imidacloprid had a quicker knockdown rate.

Frontline comes in a 3-month supply for about half the cost of the K9 Advantix 2 standard 6-month supply. 

Winner goes to K9 Advantix: Despite being a little more expensive, we've received multiple reports that people are leaving Frontline for Advantix and seeing better results. This would make sense as the ingredients in Advantix have been seen to be slightly more effective.

K9 Advantix II vs. Capstar Flea Tablets

The primary difference in these two products is in how they work: Capstar is an actual pill that dogs must swallow in order to rid the body of fleas, where K9 Advantix are drops applied to your dogs skin.

As you probably know, it can be incredibly difficult to make your dog swallow stuff that isn't food. As it’s hard enough for some humans to swallow pills, let alone dogs.

Also, the medication goes into the dog’s bloodstream to work, whereas with K9 Advantix II, the medicine simply sits on the surface of the skin.

Winner goes to K9 Advantix II: We're going to give the edge to K9 Advantix again as many customers report how easy it is to apply the drops to their dog's skin with little to know fuss (or biting). When it comes to pills, dogs can be very picky despite how much peanut butter you use to help making it more enticing. 

K9 Advantix II vs. Seresto Flea and Tick Collar

The Seresto Flea Collar is a non-invasive, effortless dog collar used to protect your dog from parasites like fleas and ticks.

The collar itself uses the same active ingredients as K9 Advantix II (imidacloprid and permethrin) but instead of a topical serum application once per month, the collar releases this formula at intervals of time to give continuous protection to your dog.

The collar costs less and lasts for 8 months as opposed to K9 Advantix II, which comes in a 6 month supply and costs a bit more.

Verdict is a draw: Honestly, this one comes down to your budget and your dog's personality. We would try K9 Advantix II first to avoid putting anything around your dog's neck. After about a month, evaluate the results and then try the collar. 

SECTION 6: The Bottom Line

The old adage really is true...

...you get what you pay for.

With K9 Advantix 2, you're paying for top-quality flea and tick medication with a satisfaction guarantee. There's a reason that this medication is at the top of the market: its effective rating is at the top, and its customer satisfaction is largely through the roof.

A word of warning: be sure to weigh your dog and purchase the formula that corresponds to your dog's weight. If you buy a solution that's suited for a heavier dog, you may think that you're doing more to kill fleas. However, this overdose of the active ingredient will burn your dog's skin. Use caution and be sure to get the formula that is right for your dog's size.

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Rating: 97.50

Our #1 Ranked For: Termites,Bed Bugs, and Larger Infestations


Rating: 97.00

Our #1 Ranked For: Ants, Roaches, Spiders, and Rodents Issues


Rating: 95.70

Our #1 Ranked For: Mosquito Removal, Fleas, Ticks, Wasps, And Other Stinging Insects

8 thoughts on “K9 Advantix II Review and Comparison (2021 Edition)”

  1. Advantix II has been very effective on my dogs for the past few years. Lately, however, it seems that fleas are developing an immunity to Advantix II. Had the same problem with Frontline several years ago. With probably have to go to Comfortis or Nexgard for flea control.

  2. I’ve lost confidence in Advantix ll as an effective approach to tick disease prevention. We live in New England and start applying the product, according to directions on March 1. While I’ve encountered ticks during thaws in February in prior years, when there is snow cover usually that are not to be found. We had a few inches of snow into early to mid April this year and the ticks aren’t fazed.
    Ten days after the first application in March I found the first engorged tick and thereafter at least one to two engorged and very alive ticks every week after that. What motivated me to write this comment tonight is that less than two hours ago I removed three very healthy and large engorged ticks off my dog’s chest. Remember it was less than three weeks ago that I applied application number two. The same thing basically happened last year and the response I got from the very helpful people at Bayer was to apply it more frequently. To what end? Every week?
    Our region is known for fairly heavy tick infestation – no flea issues ever for me. But I’m disillusioned by the effectiveness of Advantix ll right now. Three years ago this was not the case, so my conclusion is that the ticks are developing a resistance that Bayer is not ready to publicly address. I’m thinking about the Seresto collar but hate the idea of keeping any kind of collar on a dog around the clock – too many issues regarding potential choking if they get hung up or other dogs teeth getting snagged on the collar when they play – which is a daily occurence even though it’s supervised play. Lastly, I’ve tried every “natural”, “holistic” approach and none of them have ever worked…

    • Hey Vic, sorry to hear about your troubles.

      Yes, indeed ticks (and other pests) are developing resistances to certain chemicals. That’s actually one of the main reasons bed bugs are on the rise.

      I would give Seresto a go as it does have a different chemical composition with Flumethrin/Imidacloprid being the active ingredients vs Imidacloprid, Permethrin, Pyripoxyfen, which are in the Advantix drops.

      Let us know what you end up doing!

  3. I used a dose on my my 7 week old puppy last we had just gotten her and the poor baby was infested with fleas she had missing hair and scabs all over. I put it on her lastnight and this morning I found a bunch of dead fleas and she wasn’t scratching anymore so I highly recommend this product might be a little pricey but worth the results and actually works unlike the cheap brands ?

  4. I have been using this product for many years on our two dogs..It has stopped working for them..I checked to make sure of the date I used last months…three weeks ago..today I checked my dogs after seeing them scratching away…many fleas….I just reapplied..hope this does its job….hoping this product hasn’t changed its formula.


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