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K9 Advantix II Medium Dog Vet-Recommended Flea, Tick & Mosquito Treatment & Prevention | Dogs 11-20 lbs. | 6-Mo Supply

  • Based on 32,072 reviews
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Availability: In Stock.
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Arrives Wednesday, Mar 11
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Size: 6 Pack


Features

  • K9 Advantix II Medium Dog 30-day treatment & prevention protects dogs 11-20 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 Medium 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 Medium 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 11-20 lbs. to use K9 Advantix II Medium 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 Medium Dog is a trademark of Elanco or its affiliates.

Brand: K9 Advantix


Item Form: Topical


Scent: Unscented


Item Weight: 0.11 Pounds


Active Ingredients: Imidacloprid, Permethrin, Pyriproxyfen


Item Volume: 6 Milliliters


Allergen Information: Allergen-Free


Dog Breed Size: Medium


Age Range (Description): 7 weeks and older


UPC:


Is Discontinued By Manufacturer ‏ : ‎ No


Product Dimensions ‏ : ‎ 7.9 x 5 x 2.3 inches; 1.76 ounces


Item model number ‏ : ‎ 86315122


Date First Available ‏ : ‎ October 5, 2004


Manufacturer ‏ : ‎ Elanco US Inc


Best Sellers Rank: #695 in Pet Supplies (See Top 100 in Pet Supplies) #6 in Dog Flea Drops


#6 in Dog Flea Drops:


Customer Reviews: 4.4 4.4 out of 5 stars (33,455)


Item Weight: 1.76 ounces


Manufacturer: Elanco US Inc


Item model number: 86315122


Date First Available: October 5, 2004


Item Package Dimensions L x W x H: 6.61 x 4.33 x 1.46 inches


Item Dimensions LxWxH: 7.9 x 5 x 2.3 inches


Item Weight: 0.11 Pounds


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 two or three 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: France


Warranty Description: Available from manufacturer upon request


Model Name: K9 Advantix II


Color: Medium Dog only


Size: 6 Pack


Age Range Description: 7 weeks and older


Number of Items: 1


Style: Medium Dog Only


Breed Recommendation: Medium Breeds


Included Components: 6 MONTH K9 Advantix II TEAL for Medium Dogs (11-20 lbs)


Specific Uses for Product: Parasites


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Wednesday, Mar 11

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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Top Amazon Reviews


  • Very effective
Size: 2 Pack
Works great to get rid of fleas. It also keeps the fleas away when used monthly. There isn’t a strong odor. The product fully absorbs in about 2 days so others due is mildly greasy for a day. Good value .
Reviewed in the United States on February 24, 2026 by Nadiya Stewart

  • I use this and it works for all 6 of my dogs.
Size: 6 Pack
The media could not be loaded. I have used this for years. You apply to their back. It is easy to use and not messy. My dogs have not gotten fleas or any other bites. I will continue to use. It works well and lasts for the month if not longer. The dogs do not notice it on them. Do not scratch or try to lick it. Great for the price. I have not noticed any side effects. ... show more
Reviewed in the United States on January 27, 2026 by Laura Rodriguez

  • Does not kill fleas
Size: 6 Pack
I have used these for years and the last 3 months supply has been a disappointment they are not killing the fleas at all. My babies still have fleas crawling all over them after application. I will no loner be buying this product.
Reviewed in the United States on January 26, 2026 by M. Edwar

  • Quickly Quashed Flea Problems On Pet
Size: 2 Pack
Small flea problem outbreak. Quickly eradicated the flea issue on my pet.
Reviewed in the United States on January 24, 2026 by thefuturefyre

  • Bye-Bye Bugs, Hello Happy Pup 🐾🛡️
Size: 2 Pack
K9 Advantix II keeps fleas, ticks, and mosquitoes far away from my small dogs. Easy to apply, vet-recommended, and works fast — no more itchy, grumpy pups. Peace of mind for me, tail wags for them. Highly recommend if you want a pest-free pooch.
Reviewed in the United States on December 24, 2025 by SurfsUp

  • Thankfully, it works!
Size: 1 Pack
We have fought fleas on all fronts in our hot and muggy rural area. Frontline and the generic version- useless. Sprayed the land, treated our home, sprayed our dog with an additional temporary spray. This is the first time we've ever had such problems. Dog was constantly scratching, visible fleas and flea dirt. Flea comb simply full of mature fleas and flea dirt. Two vet visits in which we were told the next step was a yearly and expensive treatment. Thankfully, found this on Google as vet recommended. Bought a dose here. It arrived yesterday and we immediately applied as directed to 15 lb dog. He was fine upon application. No major problems afterwards but did began to claw himself aggressively and nip at his paws. Found those relatively minor results on the carton safety data and saw no reason to be overly concerned. I did give him the dose of antihistamine as prescribed by our vet. I think the fleas were 'abandoning ship'! He became drowsy within about 40 minutes settled down and slept soundly all night. No raw spots or other problems today but he looks like a newer, improved dog today. He is basically white. Today there were no visible fleas or flea dirt. Yes! So glad we found this product, all I will buy again! Great customer support because I called the # on the product box today just to check his reaction. They were great. ... show more
Reviewed in the United States on July 23, 2025 by a customer

  • Durability and usefulness claim is wrong.
Size: 2 Pack
We'll moved out to the country from the city and my dog never had fleas in the city. But out here in the country, it seemed the fleas love him. I bought this stuff on December the 12th applied it immediately. today is December 27th if you see the pictures that I've posted with this review I've already picked multiple fleas off my poor dog And there's tons more flea dirt all over places. Disappointed that this name brand flea medication hasn't even lasted its 30 days. I mean, yes, it worked for a brief period like two weeks, and then now the fleas are back. So I'm gonna go ahead and reapply it, but I'm not purchasing this brand again. I'm gonna try something else. im very disappointed and my poor dog is just as itchy as before the 1st application. ... show more
Reviewed in the United States on December 28, 2025 by Jennifer Jennifer

  • Great flea treatment
Size: 6 Pack
Amazing product. The only brand I use to keep fleas of my Lil guy. Works fast and last a long time. Makes him a Lil lethargic on the first day of applying. But back to normal the next day. Keeps the fleas at bay an is waterproof
Reviewed in the United States on December 18, 2025 by David Phillips

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