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K9 Advantix

K9 Advantix II Medium Dog 11-20 lbs & Large Dog 21-55 lbs Vet-Recommended Flea, Tick & Mosquito Treatment & Prevention | 2-Mo Supply Each

  • Based on 42,508 reviews
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Availability: In Stock.
Fulfilled by Amazon
Arrives Tuesday, Jun 24
Order within 11 hours and 28 minutes
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Size: 2 Pack


Style: With Medium Dog


Features

  • Contains one 2-pack of K9 Advantix II for Medium Dogs 11-20 lbs and one 1-pack of K9 Advantix II for Large Dogs 21-55 lbs. Do not use on cats.
  • K9 Advantix II 30-day treatment & prevention protects dogs from fleas, ticks, mosquitoes, biting flies and lice
  • Kills fleas within 12 hours of application
  • Vet-recommended formula kills & repels on contact so fleas dont have to bite your dog to die
  • Easy-to-apply topical treatment is fragrance-free and waterproof after 24 hours
  • No prescription needed

Description

K9 Advantix II is the veterinarian-recommended formula that helps defend your dog against five pests: fleas, ticks, mosquitoes, biting flies and lice. And unlike other treatments, K9 Advantix II kills and repels fleas, ticks and mosquitoes. K9 Advantix II topical treatment gets straight to work killing fleas on dogs within 12 hours of initial application. This formula stops existing flea infestations and prevents new ones by killing adult fleas on contact so they can’t lay eggs and they don’t have to bite your dog to die. K9 Advantix II topical, spot-on formula makes application simple - going on in seconds. You’ll also love that K9 Advantix II is fragrance-free and waterproof after 24 hours of application. K9 Advantix II pest protection is effective on both indoor and outdoor dogs. K9 Advantix II is a trademark of Elanco or its affiliates.

Brand: K9 Advantix


Item Form: Topical


Scent: Unscented


Dog Breed Size: Large


Age Range (Description): Adult


Date First Available ‏ : ‎ January 11, 2021


Manufacturer ‏ : ‎ Elanco


Best Sellers Rank: #188 in Pet Supplies (See Top 100 in Pet Supplies) #5 in Dog Flea Drops


#5 in Dog Flea Drops:


Customer Reviews: 4.4 4.4 out of 5 stars 42,508 ratings


Manufacturer: Elanco


Date First Available: January 11, 2021


Brand Name: K9 Advantix


Color: With Medium Dog


Size: 2 Pack


Age Range Description: Adult


Style: With Medium Dog


Breed Recommendation: Medium, Large Breeds


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Tuesday, Jun 24

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View our full returns policy here.

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Similar Products

Top Amazon Reviews

    • It works
Size: 2 Pack Style: Large Dog only
My dog was on a prescription medication before this. I had to stop her previous medication because it was out of stock for a while and when it was restocked, the price skyrocketed to $250 for a 6 month supply instead of the usual $120 that it was prior. There was a new generic version of her prescription but after reading the reviews on that, I didn’t want to risk my dog’s health. During that time of her not being on any preventative, we ended up with a flea problem in my area which we never had before. Since the fires, a lot of wildlife has been dropping by in my neighborhood and with wildlife comes fleas just hitching a ride with them. We fell victim to an infestation in our backyard and surrounding areas. I panicked and tried the holistic approach for months with DE, changing my dog’s diet, essential oils, etc to no avail. I had to try something because my dog is old and I really didn’t want to stress her by taking her to the vet for yet another prescription (which all had extremely negative adverse effects after doing plenty of research). I decided to try an OTC flea treatment and it was between this one and frontline. After doing more research, I opted for Advantix II since it was more effective than frontline (for my area). So glad I did because fleas were gone within a day. My dog has been on this for a year now and so far it is working. I did find a flea on her the other day right after we got back inside from our little walk and was able to grab it. I put it in a ziplock bag with a piece of my dogs shedded fur just to see if the treatment was still working since it had been 26 days since I used Advantix and within 2 hours of that flea crawling on her fur in that bag, it was dead. So I know for sure that this medication is working and working effectively at that. She was groomed two days prior to me finding a flea on her as well (she had a waterless bath and is wiped down with her dog wipes daily) - the bath and wipes didn’t minimize the effectiveness of this flea medication which is a huge plus! What I’ve learned throughout this whole process is that no treatment is going to immediately kill or prevent fleas or ticks - not even prescription medication - Advantix has saved me hundreds if not thousands of dollars on prescriptions and it’s still as effective as a prescription. It’s a win - win in my book and I will continue to use this year round to keep my dog protected. ... show more
Reviewed in the United States on June 10, 2025 by Amazonshopper
    • Worth the extra $, read the directions
Size: 6 Pack Style: Large Dog only
The directions say to NOT put it all in one spot like other brands, so be mindful of that to prevent irritation and harming your dog. I used frontline on my dog for years bc it was cheaper. But then last year I had a client that had a flea problem and I apparently brought them home with me bc my dog ended up getting infested even though she had been treated with frontline monthly. I put this on her, deep cleaned my house and sprayed everything with flea spray daily and they were gone in a week or two. I treat her with it every month now and haven't had issues. Will continue to pay the extra money as long as it continues to work. ... show more
Reviewed in the United States on June 9, 2025 by MH
    • Effective
Size: 1 Pack Style: Large Dog only
I've been using this brand a few years now works good on killing those nasty fleas. Easy to use just squeeze the tube of medicine on your dog try to get it down to the skin not just sitting on fur
Reviewed in the United States on June 9, 2025 by Jennifer Mann
    • Our dog had a severe allergic reaction.
Size: 4 Pack Style: Large Dog only
Our dog had a severe allergic reaction to this. About 2-3hrs. after we applied it he started scratching, breathing heavily and running around. I bathed him twice and administered Benadryl. He's doing much better now. We'll monitor him the next few days and find an alternative flea and tick treatment. I can't give this product a bad review because I understand it can effect dogs differently. Update 48hrs after application: Because we bathed our dog as soon as he showed signs of a reaction and administered Benadryl, we lessened the severity of his symptoms. He's not twitching or biting at his tail. His breathing is normal and he's sleeping soundly. ... show more
Reviewed in the United States on May 26, 2025 by Pap K
    • Advantix 11 flee and tick protection for dogs, excellent product. Adela
Size: 6 Pack Style: Large Dog only
I believe in this product , I buy a years worth for my seven dogs, it will always be a part of their care no matter the cost their well being is my priority. Adela
Reviewed in the United States on June 11, 2025 by Adela excellent product
    • Maybe a few coupons could help.
Size: 6 Pack Style: Large Dog only
Works well, dogs handle it good. Maybe the company can send out some coupons as it would help with the cost as I run a rescue here of dogs & cats.
Reviewed in the United States on June 10, 2025 by Elisa Taylor
    • Causes itching
Size: 4 Pack Style: Large Dog only
This product caused my dog (Shiba Ina) to itch at where I put it on his skin for several days. This previously never happened when using Bravecto. Can't speak to whether it works or not as he hasn't had fleas or ticks before, I'm using this as a preventative measure.
Reviewed in the United States on June 6, 2025 by Vel
    • Reliable Protection—No Fleas, No Ticks, No Worries
Size: 4 Pack Style: Large Dog only
K9 Advantix II has been our go-to for years when it comes to protecting our dogs—especially with all the outdoor time they get on the farm. It works fast and effectively against fleas, ticks, and mosquitoes, and we’ve had zero issues since using it consistently. The application is simple: just part the fur and apply it along the back. It dries quickly and doesn’t leave a greasy mess. What I really appreciate is that it repels pests before they even bite, which gives me peace of mind—especially in the warmer months when ticks are everywhere. Our dogs haven’t had any adverse reactions, and they’re outside constantly—running through tall grass, woods, and around livestock. It’s held up through baths and light rain too, which is a big plus. If you live rurally or have active outdoor dogs, this is one of the best defenses out there. Worth every penny for the protection it provides. ... show more
Reviewed in the United States on April 21, 2025 by Eric T.

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