K9 Advantix II Medium Dog Vet-Recommended Flea, Tick & Mosquito Treatment & Prevention | Dogs 11-20 lbs. | 4-Mo Supply
Original price was: $57.48.$40.24Current price is: $40.24.
Price: $57.48 - $40.24
(as of Oct 11, 2025 21:02:14 UTC – Details)
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.
Is Discontinued By Manufacturer : No
Product Dimensions : 7.75 x 1 x 4.25 inches; 0.8 ounces
Item model number : 86315157
Department : Pet Supplies
Date First Available : October 5, 2004
Manufacturer : Elanco US Inc
ASIN : B004QMX4RY
Best Sellers Rank: #488 in Pet Supplies (See Top 100 in Pet Supplies) #6 in Dog Flea Drops
Customer Reviews: 4.4 4.4 out of 5 stars 32,783 ratings var dpAcrHasRegisteredArcLinkClickAction; P.when(‘A’, ‘ready’).execute(function(A) { if (dpAcrHasRegisteredArcLinkClickAction !== true) { dpAcrHasRegisteredArcLinkClickAction = true; A.declarative( ‘acrLink-click-metrics’, ‘click’, { “allowLinkDefault”: true }, function (event) { if (window.ue) { ue.count(“acrLinkClickCount”, (ue.count(“acrLinkClickCount”) || 0) + 1); } } ); } }); P.when(‘A’, ‘cf’).execute(function(A) { A.declarative(‘acrStarsLink-click-metrics’, ‘click’, { “allowLinkDefault” : true }, function(event){ if(window.ue) { ue.count(“acrStarsLinkWithPopoverClickCount”, (ue.count(“acrStarsLinkWithPopoverClickCount”) || 0) + 1); } }); });
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 don’t have to bite your dog to die
Easy-to-apply topical treatment is fragrance-free and waterproof after 24 hours
No prescription needed
Customers say
Customers find this pest control product effective, particularly noting it’s better than Frontline and easy to apply to the back of the neck. The product receives mixed feedback regarding its effectiveness, with some reporting no fleas or ticks while others say it didn’t work at all. Customers disagree on the product’s value, with some considering it a great value while others find it expensive. Skin reactions are mixed, with some customers reporting no adverse reactions while others experienced itching and allergic reactions. The product’s durability is also mixed, with some customers reporting it lasts for years while others say it doesn’t last 30 days. Customers report their dogs continue to scratch and chew despite treatment.
8 reviews for K9 Advantix II Medium Dog Vet-Recommended Flea, Tick & Mosquito Treatment & Prevention | Dogs 11-20 lbs. | 4-Mo Supply
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Original price was: $57.48.$40.24Current price is: $40.24.
Vincent –
After half a year of fleas, switching to this product completely got rid of them!
Cannot recommend enough! I live in the middle of the mountains next to a large national forest. There’s deer, beer, turkey and all sorts of wildlife moving through my yard and in the woods year round, visibly agitated by fleas.My dog of 14 years finally got fleas (she’s an inside dog with lots of outdoor playtime), as I’ve been thorough with checking her fur during brushings and baths. I usually just give her monthly flea baths which sufficed, but after a neighbor clear cut their property I’ve had an influx of wildlife on my property and I think that contributed to my dog getting fleas, I’m not sure.Regardless, she had fleas and they became an irritating presence within my home. Unfortunately, there’s plenty of carpet for them to hide in and lay eggs. Yuck!I tried everything to get rid of them! Carpet powders, flea baths (different brands), furniture spray, cheap flea drops.. nothing worked. I battled with them for almost 6 months!! My poor dog was waking up constantly scratching and pacing back and forth throughout the house. I felt like an awful parent and was going crazy before finally deciding to look into the more expensive options..Now, considering how much I spent on cheaper alternatives that didn’t work or get rid of the problem at the source, I really wish I would’ve went straight for the higher priced option first. Within a matter of weeks of using this product I saw a quick decline in fleas inside the house and on my dog. Within one to two months, they were completely gone! I was in complete shock.I cannot praise this product enough. Maybe it’s so effective on the fleas in my area since I live in the rural countryside where they’re not used to it, as opposed to city fleas, so your mileage may vary. But for me this was a miracle product and I will be using this as a preventive measure in the summer months, with a periodic dose in the winter.If you struggled with fleas for months and months like I have, you will know the complete relief that comes with a flea-free home. Don’t skimp! It may be more expensive than the alternatives but trust me with I say I tried all of them and nothing came close to getting rid of them, whereas this treatment was so fast and effective I was left nearly crying when I saw my sweet dog sleeping soundly through the night. 🙂
a customer –
Thankfully, it works!
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.
Midori A –
Good product and easy to apply.
K9 Advantix II was recommended for our Westie 14 years ago and it seems to work very well for him, although we have discovered a flea rarely. Easy to apply, no smell and our Westie is okay with the application.
amberly –
Wish it lasted the whole month
Four stars because it only works two weeks for us instead of a whole month.
Gwendolyn –
Great value
Have used this brand for years on our shih-Tzus. Very effective. It controls the fleas and other bugs. Has a slight smell.Our babies have never had side effects from this brand. Does leave an oily residue for a few days. Itâs a great value since it does work. Doesnât make our dogs scratch.
Coquette07 –
A decade of satisfaction
For ten years, K9 Advantix II Medium Dog has been my go-to flea and tick preventative. My dog has remained completely pest-free, even in a high-risk area, demonstrating its consistent effectiveness month after month. Crucially, he has experienced absolutely no side effects â no irritation, no changes in behavior, just a happy, healthy pup. The application is simple. I highly recommend K9 Advantix II for reliable, long-term protection and peace of mind.
Sweetie_04 –
En la caja vienen 6 pipetas, como se indica en la descripción: 4 de ellas vienen en el sobre hermético de la propia caja y las otras 2 vienen sueltas (la caja realmente es de 4).Contenta con la calidad de Advantix, no me arriesgo a probar con otra marca.Muy recomendado por la relación calidad-precio.
Amazon Customer –
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