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K9 Advantix

K9 Advantix II XL Dog Vet-Recommended Flea, Tick & Mosquito Treatment & Prevention | Dogs Over 55 lbs. | 2-Mo Supply

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Availability: In Stock.
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Size: 2 Pack


Style: XL Dog only


Features

  • 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. Fleas, ticks, mosquitoes and other pests not only cause discomfort; they may also transmit disease. Monthly use of K9 Advantix II is important to protect your dog against fleas that may cause transmission of tapeworms. This formula also kills fleas which may cause Flea Allergy Dermatitis and flea bite anemia. That’s why K9 Advantix II Extra Large Dog topical, spot-on formula makes application simple - going on in seconds. It's easier than a flea collar and there are no hard-to-swallow pills. You’ll also love that K9 Advantix II is fragrance-free and waterproof after 24 hours of application. Check the product label for information on application and potential side effects. K9 Advantix II pest protection is effective on both indoor and outdoor dogs. Your dog should be at least 7 weeks old and weigh over 55 lbs. to use K9 Advantix II Extra Large Dog. For the ultimate convenience in care, K9 Advantix II is available over the counter – no prescription needed. And, you can stock up with 2-dose, 4-dose and 6-dose packs so you never miss a monthly treatment. Once K9 Advantix II is applied, your dog is ready to get right back to big-pup cuddles and racing around the park. K9 Advantix II Extra Large Dog is a trademark of Elanco or its affiliates.

Brand: K9 Advantix


Item Form: Topical


Scent: Unscented


Item Weight: 1.13 Ounces


Active Ingredients: Imidacloprid, Permethrin, Pyriproxyfen


Item Volume: 8 Milliliters


Allergen Information: Allergen-Free


Dog Breed Size: Large


Age Range (Description): 7 weeks and older


UPC:


Is Discontinued By Manufacturer ‏ : ‎ No


Product Dimensions ‏ : ‎ 1 x 4.38 x 4.75 inches; 1.13 ounces


Manufacturer recommended age ‏ : ‎ 1 month and up


Item model number ‏ : ‎ 86314819


Department ‏ : ‎ Flea & Tick


Date First Available ‏ : ‎ January 23, 2014


Manufacturer ‏ : ‎ Elanco US Inc


Country of Origin ‏ : ‎ Germany


Best Sellers Rank: #284 in Pet Supplies (See Top 100 in Pet Supplies) #4 in Dog Flea Drops


Item Weight: 1.13 ounces


Department: Flea & Tick


Manufacturer: Elanco US Inc


Country of Origin: Germany


Item model number: 86314819


Date First Available: January 23, 2014


Item Package Dimensions L x W x H: 4.76 x 4.33 x 1 inches


Item Dimensions LxWxH: 1 x 4.38 x 4.75 inches


Item Weight: 1.13 Ounces


Brand Name: K9 Advantix


Target Audience Keyword: dogs


Directions: Application Instructions 1. Use only on dogs. DO NOT USE ON CATS or other animals. 2. The dog should be standing for easy application. Evenly apply the entire contents of the K9 Advantix® II tube to four to six spots on the top of the back from the shoulder to the base of the tail. 3. At each spot, part the hair until the skin is visible. 4. Place the tip of the tube on the skin and gently squeeze to expel a portion of the solution on the skin. 5. Do not apply an excessive amount of solution at any one spot that could cause some of the solution to run off the side of the dog. 6. Do not get this product in your dog’s eyes, or allow your dog to ingest this product.


Country of Origin: United States


Model Name: K9 Advantix II


Color: Extra-Large Dog only


Size: 2 Pack


Age Range Description: 7 weeks and older


Number of Items: 1


Style: XL Dog only


Breed Recommendation: Extra Large


Specific Uses for Product: Parasites


Frequently asked questions

K9 Advantix II is a vet-recommended treatment that effectively fights against fleas, ticks, and mosquitoes in dogs weighing over 55 lbs.

For your puppies safety, K9 Advantix II should only be applied if your puppy is older than 7 weeks.

Frequency of application should be every month. This product comes with a 2-month supply.

No, K9 Advantix II does not require a veterinary prescription, but it is always recommended to consult your vet before starting any new treatment.

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Top Amazon Reviews

🚀 Abunda's Overview

This is our summary and key points to consider based on customer reviews.

Overall, users find the K9 Advantix II flea and tick preventative to be highly effective for their dogs. Users have noticed a significant decrease in the presence of ticks and fleas and commented on the bonus element - the product does not seem to irritate their dog's skin. However, one user did report that it left a residue, which may be concerning for some.

Pros

  • 🐾 Highly effective against ticks and fleas
  • 🐾 Did not irritate the majority of dogs' skin
  • 🐾 Waterpoof feature ensures its lasting efficacy
  • 🐾 Easy to apply

Cons

  • 🚫 Can leave a residue
  • 🚫 One user reported their dog's strange behavior after application

Should I Buy It?

Based on the reviews, the product does the job it promises and has helped keep many dogs tick and flea-free. However, potential buyers should consider the reported residue left and the one isolated incident of the dog behaving oddly.

    • 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
    • Works great awesome I definitely suggested
Size: 4 Pack Style: XL Dog only
Started having dogs when we first got married we have we had seven English mastiffs yeah it’s addicting and they had puppies and everything so anyways I’ve been using this on my dogs from year 2000 and I use them before that on my other dog so I’ve always used it really and I love it. I mean, I swear by it this stuff is great. My dogs do not get flea or I mean I have to put a spray on them to detail the mosquitoes, but don’t see my bugs biting them. It’s pricey, but it’s worth it. You don’t wanna have your dogs get Lyme disease or you know from ticks, I really suggest this. No bother my dog knock on wood you know in the other thing is I don’t use this year around. I only use it from spring until after fall. I don’t feel I really needed in the winter time. It’s too cold outside for anything to live so I’m up Northeast And I don’t seem to have any problem and they’re not using it as soon as spring hits that’s that boom they’re on it. ... show more
Reviewed in the United States on July 3, 2025 by ARBONNE
    • 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
    • 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
    • Works great!
Size: 4 Pack Style: XL Dog only
These are great for our dog. She takes them as it is a treat. We rely on these to keep the fleas and ticks away. Haven't seen a one since we started using them.
Reviewed in the United States on July 11, 2025 by Colleen
    • 5 Stars – Effective and Reliable Flea & Tick Protection
Size: 2 Pack Style: XL Dog only
I’ve been using K9 Advantix II on my dog for a few months now, and it really works! It starts killing fleas quickly and keeps protecting against ticks and mosquitoes for a full month. Super easy to apply, and I’ve had zero issues with skin irritation or side effects. The smell is a bit strong at first, but it fades within a day. Just be careful if you have cats, as it’s not safe for them. Overall, it’s worth the price for peace of mind and a happy, itch-free pup. Highly recommend ... show more
Reviewed in the United States on May 7, 2025 by Amazon Customer
    • Worth the $
Size: 4 Pack Style: XL Dog only
While this is on the slightly more pricier side compared to other products on here, it works well! Definitely worth the money! I noticed a couple fleas in my house and our dogs are both inside and outside of the house, they are the culprits. I used the solution and put it behind both of the backs of their necks and I haven’t seen a flea since. I recommend it! Worth the money for sure! ... show more
Reviewed in the United States on June 30, 2025 by Cheyenne

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