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K9 Advantix

K9 Advantix II XL Dog Vet-Recommended Flea, Tick & Mosquito Treatment & Prevention | Dogs Over 55 lbs. | 3-Mo Supply

  • Based on 45,956 reviews
Condition: New
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Availability: In Stock.
Fulfilled by Amazon
Arrives Tuesday, Jun 24
Order within 14 hours and 19 minutes
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Size: 3 Pack


Style: XL Dog only


Features

  • Contains one 2-pack of K9 Advantix II for Extra Large Dogs over 55lbs and one 1-pack of K9 Advantix II for Extra Large Dogs over 55lbs. Do not use on cats.
  • K9 Advantix II Extra Large Dog 30-day treatment & prevention protects dogs over 55 lbs. 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 Extra Large Dog 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 Extra Large Dog 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 Extra Large Dog is a trademark of Elanco or its affiliates.

Brand: K9 Advantix


Item Form: Topical


Scent: Unscented


Dog Breed Size: Giant


Age Range (Description): Adult


Date First Available ‏ : ‎ October 6, 2022


Manufacturer ‏ : ‎ K9 Advantix


Best Sellers Rank: #112 in Pet Supplies (See Top 100 in Pet Supplies) #3 in Dog Flea Drops


#3 in Dog Flea Drops:


Customer Reviews: 4.5 4.5 out of 5 stars 45,956 ratings


Manufacturer: K9 Advantix


Date First Available: October 6, 2022


Brand Name: K9 Advantix


Target Audience Keyword: dogs


Color: Extra-Large Dog only


Size: 3 Pack


Age Range Description: Adult


Style: XL Dog only


Breed Recommendation: Giant Breeds


Frequently asked questions

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

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Similar Products

Top Amazon Reviews

    • The safest and most effective tick protection - ticks fall off just from touching the fur
Size: 6 Pack Style: XL Dog only
I brought my dog to West Virginia, and thank God for Advantix II — because I’ve been finding half-dead ticks every single day (no joke) in places where she sleeps or rests. At first, I was confused. I thought "repels ticks" meant it would work like bug spray does for mosquitoes, keeping them away completely. But after looking into the active ingredient, permethrin, I realized that in this case, “repel” means: once a tick touches the treated fur, it becomes so irritated or neurologically impaired that it can’t bite, can’t hang on, and eventually just falls off and dies. That’s still so much better than PetArmor, Frontline, or any of the oral preventatives (like Simparica or NexGard), which require the tick to bite the dog before it dies. No thanks. Every tick I’ve found so far had already dropped off my dog before it had a chance to bite her and feed — exactly what you want in a tick-heavy area. I’ve also tried Wondercide (cedar oil). It works okay for fleas, but it’s just not effective for ticks, especially not in the long term. Its protection wears off after 2–4 hours. I learned the hard way — my dog caught Lyme disease, developed joint pain and a limp. Thankfully, doxycycline helped and she’s okay now, but it required a full 28-day antibiotic course. I would never use oral flea/tick medications. Just ask around — you’ll hear plenty of stories about dogs having seizures after taking them. For me, that risk isn’t worth it. If you have a cat at home, unfortunately Advantix II may not be right for your household — permethrin is toxic to cats (especially when wet). But if you don’t have cats, I highly recommend this product to all dog owners. Tick-borne diseases are no joke. Fleas are annoying — I’ve had to go through the nightmare of clearing an infestation — but at least they just suck blood without causing life-threatening illness. Ticks, on the other hand, can transmit Lyme, Ehrlichia, Rocky Mountain spotted fever, and more. So if you live somewhere warm, humid, grassy, or deer-heavy — do your dog a favor and get Advantix II. It’s been a lifesaver for us. ... show more
Reviewed in the United States on June 4, 2025 by yishin
    • This will get rid of fleas on large dogs in one dose
Size: 6 Pack Style: XL Dog only
Review Image by Tambi Rosendahl Tambi Rosendahl
This is my German Shepherd and I have tried many different brands of flea medicine for my dog, and after being applied, he would itch and itch and itch as if I never gave him any medicine at all. This is the first brand that I put it on and he stops itching within 24 hours. I hate watching him scratch himself and cry because he’s itching from fleas. He’s a big dog. He has lots of fur. This medicine works within the 24 hours. The negative is it leaves a waxy greasy buildup behind his neck where I deposit it for about four days, but it does not smell. It just looks oily. I will take the oily look any day over him being uncomfortable and itching. In the past, I would end up using two treatments out of other brands and he would still itch so this one is for bigger dogs and it definitely covers him completely for 30 days. I do put a new one on every 30 days just because I don’t want fleas in the house. It’s not easy to find a good flea medicine that actually works this one. I promise you does so it’s worth the extra money because I only have to use one packet every 30 days not to like I do with other brands. ... show more
Reviewed in the United States on May 28, 2025 by Tambi Rosendahl Tambi Rosendahl
    • Flea death commeth!
Size: 2 Pack Style: XL Dog only
Dealing with a flea problem and this was recommended. It is definitely a walking flea killer. Our dog is 80lbs. After I apply this I see dead fleas on her bed and the ones still on her are moving at a fraction of the speed. We reapplied after 3 weeks due to her weight and this is for dogs 55lbs. Cannot let the fleas get a moment of rest. This is our first issue with fleas after a lifetime of having pets and it is a nightmare so I empathize with those going through it. I vacuum daily in the main bedroom. No pets on the bed for our sanity to have one space in the house that is for sure 100% flea free. Yard was sprayed and bought Nyguard to spray in the house. We do everything natural so it has been sad to turn to chemicals but when you become desperate you cave to what works best. I've tried essential oils and not sure how much that deters fleas. We also have a small dog and a cat. Pest guy says squirrels are main carriers for fleas so that is all we can figure out for how they got here. Or the cat that does wander at night. Also weekly baths on the dogs. The cat got a bath but he is black and I have yet to see a flea although he is always scratching. Also using homeopathy remedy so look that up. Good luck! ... show more
Reviewed in the United States on April 23, 2025 by Shalker
    • Effective Spot-On That’s Easy on the Wallet
Size: 4 Pack Style: XL Dog only
I switched to this flea, tick, and mosquito treatment for my XL dog (over 55 lbs) because it’s noticeably cheaper than getting K9 Advantix II locally—and it delivers solid protection. Application is simple and mess-free, and my vet gave it the thumbs up. I haven’t seen any fleas or ticks, and my dog’s coat looks healthy and shiny. It’s not perfect—occasionally I worry about skin sensitivity after application, so I always monitor for redness or irritation. Also, the dropper could use clearer measurement markings—it’s easy to misjudge dose if you’re not careful. But overall, I feel I’m getting great value without cutting corners on quality or safety. ... show more
Reviewed in the United States on June 18, 2025 by Larry Flaxman
    • Worked on my Great Pyrenees
Size: 4 Pack Style: XL Dog only
The day after applying this product on my Great Pyrenees, I noticed a few blood filled ticks falling off of him. I didn't know he had such large ticks on him. GP have very thick double coats and getting down to the skin is difficult. I'm pleased with this product.
Reviewed in the United States on June 6, 2025 by William Dixon
    • Gone
Size: 4 Pack Style: XL Dog only
My dalmatian and shepherd were getting destroyed by fleas. I bathed and flea combed both but they kept coming back. We used K9 Advantix and the next day I noticed all the fleas were gone. It has been several days now and they are still gone. Very effective.
Reviewed in the United States on June 6, 2025 by Renee
    • Fleas gone in a flash
Size: 6 Pack Style: XL Dog only
Great product and it works. We have 5 dogs and none have fleas thanks to this product. Our Pomeranian got fleas so we had to treat all the dogs and we applied this and no fleas since. ( Note we got the small dog size of this product for the Pomeranian) Great prove if you have multiple dogs to treat and it's easy to apply. Directions are easy to follow. ... show more
Reviewed in the United States on May 25, 2025 by tricia

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