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K9 Advantix

K9 Advantix II XL Dog Vet-Recommended Flea, Tick & Mosquito Treatment & Prevention | Dogs Over 55 lbs. | 4-Mo Supply

  • Based on 46,695 reviews
Condition: New
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Arrives Thursday, Jun 11
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Size: 4 Pack


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: 0.1 Pounds


Active Ingredients: Imidacloprid, Permethrin, Pyriproxyfen


Item Volume: 16 Milliliters


Allergen Information: Allergen-Free


Dog Breed Size: Large


Unit Count: 4 Count


Age Range (Description): 7 weeks and older


Is Discontinued By Manufacturer ‏ : ‎ No


Product Dimensions ‏ : ‎ 1.38 x 4.38 x 4.75 inches; 1.6 ounces


Item model number ‏ : ‎ 86315017


Department ‏ : ‎ Unisex-Adult


Date First Available ‏ : ‎ October 5, 2004


Manufacturer ‏ : ‎ Elanco US Inc


Best Sellers Rank: #152 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 (48,537)


Brand Name: K9 Advantix


Age Range Description: 7 weeks and older


UPC: 724089204103


Global Trade Identification Number: 03


Manufacturer Part Number: 86315017


Model Number: 86315017


Unit Count: 4 Count


Included Components: 4


Warranty Description: No_warranty


Manufacturer: Elanco US Inc


Item Type Name: Topical


Item Form: Topical


Scent Name: Unscented


Dog Breed Size: Large


Target Species: Dog


Item Weight: 0.1 Pounds


Volume: 16 Milliliters


Allergen Information: Allergen-Free


Active Ingredients: Imidacloprid, Permethrin, Pyriproxyfen


Frequently asked questions

No, the K9 Advantix II XL is intended specifically for dogs over 55 pounds. Using it on a smaller dog may result in an overdose, as the doses are tailored to the weight of the dog.

Yes, the K9 Advantix II remains effective after bathing, water immersion, or exposure to sunlight.

This product is designed for monthly use. Just one application per month provides multi-stage flea, tick, and mosquito protection. Overdosing can be harmful to your pet.

Some dogs may experience temporary irritation at the application site. If signs persist or become severe within a few days of application, consult your veterinarian immediately.

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Top Amazon Reviews

🚀 Abunda's Overview

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

These reviews overwhelmingly suggest a positive customer experience with K9 Advantix II flea and tick medication. It's praised for relieving dogs of itching and discomfort caused by pesky intruders such as fleas, ticks, biting flies, and mosquitos. Users report that the product is reliable and effective across different dog breeds and sizes, providing quick relief and consistent results. Some reviewers express their loyalty to this brand, stating it outperforms its competitors.

Pros

  • 🐾 Highly effective against a range of parasites like fleas, ticks, mosquitoes, and biting flies
  • 🐕 Works consistently across different dog breeds and sizes
  • 💪 Trusted by loyal users as a superior product compared to competitors
  • 🚀 Provides quick relief from discomfort caused by bug bites

Cons

  • 💸 A bit on the expensive side, especially for larger packs
  • 📦 Concerns about packaging, with one customer reporting receiving an opened box

Should I Buy It?

Absolutely. Considering the high effectiveness, reliable results, and customer loyalty towards the product, purchasing K9 Advantix II appears to be a wise investment for your dog's health and comfort. Just keep in mind, it's slightly pricier than some other options on the market.

    • Certainly the Best for Ticks Certainly the Best for Ticks
Size: 6 Pack
Review Image by Bastian
My dog is a Great Pyrenees at 100lbs. I use one of these per month as per the directions. Never knew if it worked until today. Found a handful of ticks I picked off in the parking lot after some grass on my dog, then one more 30 minutes later when I got home on her inner thigh that was half curled up and unresponsive. Hours later even after a thorough tick check I find what looks like dirt on her tail area, picking it up with a glove to see it was a deer tick completely dead and unresponsive. No ticks had ever bitten her at all. Fantastic product! Saves my dog, me, and anyone else in my household - they don’t just fall off they just die. Thank you! ... show more
Reviewed in the United States on May 20, 2026 Reviewed in the United States on May 20, 2026 by Bastian
    • Great product for small dogs
Size: 2 Pack
My mom lives out in the rural sticks. Her herd of small dogs has thrived out there for years, usually with no attention paid to fleas and whatnot until it becomes a problem. The solution was always a flea bath, maybe some Adams spray, and they are good to go until the next time. I'm not sure which is most to blame, but between the recent hot weather and the addition of ~20 chickens to her zoo (which in turn brings in unknown numbers of flea and tick covered rodents to get into the chicken feed and predators to try to get chickens), the fleas are thriving outdoors. ....and after many years of inconsistent flea protection they were thriving on her dogs, who primarily live indoors. Now, I am working to combat an active flea infestation in her house. The first application of this stuff has the dogs happier and not scratching as much. With the help of some 1ml oral syringes, I was able to turn one XL dog dose into 4 XS to Medium doses with just over a Medium dose to spare. That makes it pretty darn cheap for a product that works really well. It is an active infestation, so they are bound to get some fleas here and there and scratch a bit. It comes with the territory. Until the fleas are knocked down outdoors and until their life cycle is broken indoors, there will be fleas. Fighting an indoor flea infestation WILL take 6 weeks or a bit longer. I can't speak for how consistent this product is, as most products can have a dud here and there, but I have serious doubt with regard to all the people giving negative reviews because their dog got a few fleas after this product was applied. I don't know their back story, but fleas don't just sprout from the air and ticks are unlikely to fall off in a day. Odds are they have a yard and/or house full of fleas (just like I'm dealing with) and are expecting this to work miracles. It won't. Also, could be that they applied it to the dog's fur rather than on the dog's skin where it can be adsorbed. First off, CONTROL THE WILD FLEAS. Use an IGR in and around your house, and also get the proper microencapsulated pesticide for your usage case. If you have no cats around, permethrin based is great - like Onslaught Fastcap, Bifen I/T, or whatever indoor bug spray from the local hardware store. Wet down every bit of flooring, every baseboard, every access point. Let it dry before you let anyone/anything back in. Repeat every 2 weeks. If there are cats, use something cat safe like some hippie plant oil based garbage that needs to be applied every few days or do your own research and find an effective product. Get some insecticide granules and a spreader for your lawn. If cats, use Sevin or some hippie formulation (or whatever). If no cats, you have more options including Bifen L/P, Spectracide Triazicide, Talstar PL -- or even a cat-safe hippie formula if you just want use a less effective product and apply it way more often. Always wet the granules down after spreading. There is rarely a magic bullet when you're fighting nature. ... show more
Reviewed in the United States on October 8, 2025 by Its8up
    • Works great awesome I definitely suggested Works great awesome I definitely suggested
Size: 4 Pack
Review Image by ARBONNE
UPDATE I don’t know what y’all all your people take your dogs to the vets instead of showing them online here that they can’t walk. The fur is falling out of the bleeding. That’s ridiculous. Take your dog to the friggin neck. Let the vet determine the cause exactly and then if it’s in clause because of this then Put a negative and state the fact that you took him to a vet and the vet did test and it was the closet because I’ve been using this product for 25 years on my dogs back then and my new dogs now my dogs I had 16 years ago dogs I had 10 years ago dogs I had 13 years ago my 16 1/2 year old cocker spaniel has had this from the day he could actually have this And I have never had a problem with that on any of my dogs especially him you know it got rid of the fleas and I noticed a few texts very easy to get off compared when I didn’t use it like if I skipped a couple of months and they had a dick and I was like oh my God and then I would try to get it off and it was a hassle. I mean, it did not pull up. Come out whatever And so I put them back on this every month originally and if they get a tick and I see it. I just need tweezers and it just pops right off no eggs inside nothing no problem with the weather did not cause any of my dogs ever itch or lose hair so I think you people have an undergoing problem with your dog that you did not address Prior to use this. Yes, I’m gonna blame you. Yes I’m blaming all you that people that has undermining problems with their dog and you don’t take them to the vet and you add this product on top of them. Yes, it probably will do something like that. SO I REPEAT, TAKE YOUR DOG TO THE GD VETERINARIAN PROFESSIONAL LET THE PROFESSIONAL DO THEIR WORK !!!! Oh, I also have one dog right now. I have three of them English mastiff and I have one of them that sits at my back gate in the dirt never has fleas never has sticks never has any. He lays in the dirt 185 pound and his head I can look it out right now his head is in it. His whole body lengthwise is in it and I swear he digs holes just you know it makes it cool.. and there’s a picture of him laying at the fence in the dirt. He loves it. I check them every day. Nobody has fleas. Nobody has anything so you people are doing something wrong. I’m gonna blame all of you. They have a problem and I’ll say it again again again they have underlining problem TAKE THEM TO THE VET VETERINARIAN HAVE THE VET, VETERINARIAN, TECHNICIAN, AND DOCTOR EXAMINE THE DOG TAKE SKIN GRAPHS WHATEVER THE BEST HAS TO DO. DON’T BLAME THE PRODUCT UNLESS YOU DID THAT AND IF YOU DID IT AND THEN DOCTOR RUNS TEXT AND SAID YES, IT WAS CAUSED BY THAT PRODUCT. WELL HENCE THERE YOU GO AND IT’S THE PRODUCT FAULT BUT A 99.999% IT’S NOT THE PRODUCT. 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 Reviewed in the United States on July 3, 2025 by ARBONNE
    • Good
Size: 1 Pack
It actually works better than I thought. My dog went from scratching and bitting constantly to every now and then. Still see a flea occasionally but nothing like before I used it. Easy to apply. No for. Not sure that it last the full 30 days but I’ll take 20!
Reviewed in the United States on May 7, 2026 by a white
    • Comprehensive parasite protection—keeps pests away before they ever bite!
Size: 4 Pack
• Broad-Spectrum Defense: Provides exceptionally reliable protection against fleas, ticks, mosquitoes, biting flies, and lice on extra-large dogs. • Repels on Contact: It works through contact, meaning pests are repelled and killed before they have a chance to bite your pet and transmit harmful diseases. • Convenient Waterproofing: The topical application dries quickly and remains fully effective even after swimming, baths, or exposure to rain. ... show more
Reviewed in the United States on May 16, 2026 by Jake hancock
    • Great flea and tick medicine
Size: 6 Pack
Works good. No bugs on my dog. Good price? No hair loss, no odor, no side effects, durable
Reviewed in the United States on May 7, 2026 by Christina Wigal
    • Sog flea treatment
Size: 2 Pack
No fleas. Workd well. Good price
Reviewed in the United States on May 24, 2026 by Jennifer Anne butler
    • Not 100% Effective
Size: 4 Pack
It’s about 40% effective. Better off spending the extra $$ on the prescription grade stuff @ the vet but this works in a pinch if you can’t get to a vet quick enough.
Reviewed in the United States on February 6, 2026 by George V

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