--- product_id: 314573022 title: "Bayer K9 Advantix II Flea, Tick and Mosquito Prevention for X-Large Dogs, Over 55 lbs Over 55 lb 5420429" brand: "k9 advantix" price: "B/.343" currency: PAB in_stock: true reviews_count: 5 category: "K9 Advantix" url: https://www.desertcart.com.pa/products/314573022-bayer-k9-advantix-ii-flea-tick-and-mosquito-prevention-x store_origin: PA region: Panama --- # Starts working within 12 hours, lasts 30 days Waterproof after 24 hours, easy topical application Kills fleas, ticks & mosquitoes on contact Bayer K9 Advantix II Flea, Tick and Mosquito Prevention for X-Large Dogs, Over 55 lbs Over 55 lb 5420429 **Brand:** k9 advantix **Price:** B/.343 **Availability:** ✅ In Stock ## Summary > 🐾 Shield your big buddy from pests—because XL dogs deserve XL protection! ## Quick Answers - **What is this?** Bayer K9 Advantix II Flea, Tick and Mosquito Prevention for X-Large Dogs, Over 55 lbs Over 55 lb 5420429 by k9 advantix - **How much does it cost?** B/.343 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.com.pa](https://www.desertcart.com.pa/products/314573022-bayer-k9-advantix-ii-flea-tick-and-mosquito-prevention-x) ## Best For - k9 advantix enthusiasts ## Why This Product - Trusted k9 advantix brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Contact Kill Technology:** Kills pests on contact—no biting needed—so your dog stays itch-free and disease-free. - • **Vet-Recommended Defense:** Trusted by professionals to protect your XL dog from 5 pests including fleas, ticks, mosquitoes, biting flies, and lice. - • **Convenient 6-Month Supply:** Six easy monthly topical doses in one pack, so you never miss a treatment and keep your dog protected year-round. - • **Fast-Acting & Long-Lasting:** Begins killing fleas within 12 hours and provides a full 30 days of continuous protection. - • **Waterproof & Fragrance-Free:** Enjoy worry-free outdoor adventures—waterproof after 24 hours with no overpowering scent. ## Overview K9 Advantix II for extra-large dogs (55+ lbs) is a vet-recommended topical treatment that kills and repels fleas, ticks, mosquitoes, biting flies, and lice. It works fast—starting within 12 hours—and lasts a full month per application. Waterproof after 24 hours and fragrance-free, it offers hassle-free, contact-based pest control without the need for pills or collars. Available in a convenient 6-dose pack, it’s designed to keep your dog protected indoors and outdoors, preventing infestations and tick-borne diseases effectively. ## Description K9 Advantix II Extra Large Dog is the vet-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. Review: K9 Advantix II repels & kills through contact no biting needed - I have been using this product for over 16 years and I'm a dog trainer who has upwards of 23 dogs at a time in my home and I've never had a tick or a flea. The difference between K9 Advantix II is a fragrance free monthly topical that kills, repels fleas, ticks, flea larvae and eggs whích breaks the cycle, mosquitoes for up to 4 weeks that may transmit heartworms, kills lice, it's waterproof after 24hrs and also repels biting flies which all keeps your fur baby comfortable. In comparison, to just the K9 Advantix which only treats for fleas, mosquitoes, biting flies & lice. While other products like Frontline kills but does not repel ticks or fleas it requires them to bite your pet first and has no effect on mosquitoes or biting flies. Plus it's the only flea medication on the market that you can start during any of the four flea cycles which will stop them in their tracks all they have to do is simply touch your pet even during an infestation you will see it start taking effect within 12 hours, which you may need to apply a second dose that is perfectly safe to do so but not more. For your convenience it comes in several different sizes that apply to your pets weight from super small to extra extra large. While it provides the best protection on the market without a prescription needed it's not the cheapest product either but it's not the most expensive, it has a very average cost that ranges with the size of your pet to the multiple size pack you purchase from 1 to 6 tubes. It's also available for cats in addition to not having nasty side effects like other flea medications do. Inside the box there's even stickers which you can place on a calendar so you don't forget to apply the next dose the same day of the following month. I wouldn't choose another product that I would recommend this to anyone if you want peace of mind from something so easy to use, Review: Works great awesome I definitely suggested - 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. ## 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 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 ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B004QRJJ0K | | Active Ingredients | Imidacloprid, Permethrin, Pyriproxyfen | | Age Range Description | 7 weeks and older | | Allergen Information | Allergen-Free | | Best Sellers Rank | #5,026 in Pet Supplies ( See Top 100 in Pet Supplies ) #6 in Dog Flea Drops | | Brand | K9 Advantix | | Brand Name | K9 Advantix | | Customer Reviews | 4.5 out of 5 stars 41,931 Reviews | | Global Trade Identification Number | 00724089204295 | | Included Components | Tablets | | Item Form | Topical | | Item Type Name | Topical | | Item Weight | 0.1 Pounds | | Item form | Topical | | Item volume | 24 Milliliters | | Item weight | 0.1 Pounds | | Manufacturer | K9 Advantix | | Manufacturer Part Number | 86315068 | | Model Number | 81520429 | | Scent | water | | Scent Name | water | | Target Species | Dog | | UPC | 024089616501 724089204295 | | Unit Count | 6 Count | | Volume | 24 Milliliters | ## Product Details - **Active Ingredients:** Imidacloprid, Permethrin, Pyriproxyfen - **Brand:** K9 Advantix - **Item form:** Topical - **Item weight:** 0.1 Pounds - **Scent:** water ## Images ![Bayer K9 Advantix II Flea, Tick and Mosquito Prevention for X-Large Dogs, Over 55 lbs Over 55 lb 5420429 - Image 1](https://m.media-amazon.com/images/I/71gKl9aB+cL.jpg) ## Available Options This product comes in different **Size** options. ## Questions & Answers **Q: Has anyone switched over from Frontline Plus to K9 Advantix II and is happy? For Dogs** A: YES!!!! I've had the same experience with my dogs as Nicole A replied. I had been pleased with Frontline for years....but in 2012 (and ever since) it has just stopped working. One of my dogs is a fur-making machine: and fleas don't seem to bother him...even if I am finding them on him. The other dog has horrible flea allergies: has immediate, sustained, and severe "hot spots" after even just ONE flea bite...skin will turn pink all over his body...and he "blows" large amounts of his beautiful, lush, scruffy coat...and he just doesn't seem to be his usual happy, bright, and enthusiastic self :-( Using Advantix II....he seems to not have problems at all (it keeps the fleas from breeding...although if one occasional transient flea bites him....it will die...but the dog will still get a "hotspot", but nowhere as intense or sustained as without Advantix II...and if I find it quickly and clean it with vinegar, he may not even need a dose of benedryl). During the "flea season" since using Advantix II he has been able to keep his lush coat with no problems.....to such an extent that I brought him in to my vet's office just to show the vet how well he was doing one summer (the dog had been so bad the previous summer while using Frontline that I had to take him to the vet for skin reactions, fur loss in large areas of his coat, and a secondary infection from scratching...I had been so discouraged about the flea problems that year while on Frontline that I had been taking the dog daily to the lake so he could swim and drown the damned fleas). The vet was very pleased with the dog's condition with Advantix II, and had stated he has learned from his patients that they are also seeing less effectiveness with Frontline in recent years. I won't use anything else but Advantix II during this up-coming flea season. (although I do also spray his coat/skin with vinegar (mixed 1/2 with water) each day as a flea deterrent...especially if he gets a hotspot...and I add a small amount of vinegar to his food as well........and when he does need a bath: I use EXTREMELY diluted Dr. Bronner's castile liquid soap in the "EUCALYPTUS" version....the dog tolerates it well...and it seems the scent repels fleas a bit. I use the soap as well to launder the cover of his dog bed at least weekly). I know that insects can get resistent to certain pesticides over time....and I suspect that is why Frontline no longer works in our area.....I sure hope it doesn't eventually happen with Advantix II as well....and I hope that producers of flea/tick products for dogs will monitor this situation and re-formulate their products as needed to address the situation--regionally if need be. **Q: I thought I was ordering Advantage II but by mistake, ordered Advantix II. What is the difference, and does it work the same?** A: You can’t use advantix on cats. sadly because advantix 2 is superior and is the best out there because unlike advantage (and unlike frontline) it repels flies and mosquitoes as well as ticks and fleas. but it is toxic to cats. as cats should be indoors only you shouldn’t need tick/mosquito repellent just flea. DO NOT USE ADVANTIX ON CATS! It is toxic to them **Q: What about cats? I used to use Advantix on my cats with no problems, as suggested by my vet to save money. Has the formula changed?** A: Look at the active ingredients for both the dog & cat formulas; They are exactly the same. Only difference is the dosage size which you can easily look up on the internet & save yourself a ton of money **Q: Could I use this along with a flea/tick collar?** A: As a vet tech we say a flea collar is basically worthless..At most may keep fleas off pets head. If you can buy flea collar at store probably won’t work and even the script only work minimal. Stick to topical like frontline plus, advantage, advantix and oral like Capstar. Flea collars are most always a waste of $. To remove fleas fast simply bathe dog and let dog sit in water…drowning fleas and follow up in few hours with topical if bad infestation. Just a flea or 2 I’d still bathe but topical probably enough. All topicals are water resistant after 24hr ## Customer Reviews ### ⭐⭐⭐⭐⭐ K9 Advantix II repels & kills through contact no biting needed *by T***A on 8 September 2026* I have been using this product for over 16 years and I'm a dog trainer who has upwards of 23 dogs at a time in my home and I've never had a tick or a flea. The difference between K9 Advantix II is a fragrance free monthly topical that kills, repels fleas, ticks, flea larvae and eggs whích breaks the cycle, mosquitoes for up to 4 weeks that may transmit heartworms, kills lice, it's waterproof after 24hrs and also repels biting flies which all keeps your fur baby comfortable. In comparison, to just the K9 Advantix which only treats for fleas, mosquitoes, biting flies & lice. While other products like Frontline kills but does not repel ticks or fleas it requires them to bite your pet first and has no effect on mosquitoes or biting flies. Plus it's the only flea medication on the market that you can start during any of the four flea cycles which will stop them in their tracks all they have to do is simply touch your pet even during an infestation you will see it start taking effect within 12 hours, which you may need to apply a second dose that is perfectly safe to do so but not more. For your convenience it comes in several different sizes that apply to your pets weight from super small to extra extra large. While it provides the best protection on the market without a prescription needed it's not the cheapest product either but it's not the most expensive, it has a very average cost that ranges with the size of your pet to the multiple size pack you purchase from 1 to 6 tubes. It's also available for cats in addition to not having nasty side effects like other flea medications do. Inside the box there's even stickers which you can place on a calendar so you don't forget to apply the next dose the same day of the following month. I wouldn't choose another product that I would recommend this to anyone if you want peace of mind from something so easy to use, ### ⭐⭐⭐⭐⭐ Works great awesome I definitely suggested *by A***E on 3 July 2025* 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. ### ⭐⭐⭐⭐ The GOOD and BAD.. Kills EVERYTHING *by J***H on 24 January 2019* So this stuff kills and prevents it ALL! That's the good part! The bad is... it kills and prevents it all... SO if I continually put this on my dog... onto his skin.. down his back... and your skin is the largest organ that absorbs it... This cannot be good for my dog long term. I used to do this when flea/tick season was in high gear in my area (google flea/tick season for your state) and then stop in the winter months. Then I slowly just tapered off and stopped using this all together. It works and works well. My dog has no issue with it at all. The months I had put this on him, no flea or tick or mosquito in sight. It does spread into his long fur and takes a bit to dry/absorb like a day or two so that can be messy. You can't really pet him down his back at that time. You're not supposed to bathe them before or right after application. He never had any skin rashes or negative side effects from it. That being said, I personally decided to stop using it monthly. I don't take him to tick heavy areas like woods and if I do, I always, always, always do a thorough tick check on him. It's tedious, he has long, thick hair (golden retriever) but worth it 1000%. Of all the things in life I will mess around with, ticks and the diseases they carry (esp. lyme) are not one of them. Fleas, I will treat with capstar if need be but not really any fleas get on him. That being said I still purchase and keep this stuff around, WHY? because it kills everything. It's amazing to have on hand for emergencies, mainly like when a tick ATTACHES to him and I'm so scared if I pull it off wrong, it's head will still be in his skin (this is bad because it can still transmit diseases this way). SO when that happens, I get this out, put a generous DROP onto the tick and let it do it's magic. Let all those chemicals and pesticides and whatever kill that TICK at least paralyze it so it cannot bite and hold onto my dog's skin anymore. This takes, well I give it 30 seconds but usually a min or so to be safe. Then, I do what they say to do, grab the tick with tweezers and gently twist and off it comes head and all. I then, because I hate them so much (the only thing worse and scarier than spiders are ticks) burn them with a lighter. I show them NO mercy. Anyways, this product works, it doesn't have any bad effects on my dog, BUT I don't use it regularly anymore because I think it can be a lot on my dog's body/immune system. I DO keep it around though for emergencies that can and do crop up. That's part of life and owning a dog. So would I repurchase, YES, would I recommend? Yes. Just not all the time, but to have on hand. I'm not saying eliminate all chemicals and never use them, I just reduce WHEN I can. ## Frequently Bought Together - K9 Advantix II XL Dog Vet-Recommended Flea, Tick & Mosquito Treatment & Prevention | Dogs Over 55 lbs. | 6-Mo Supply - K9 Advantix II Large Dog Vet-Recommended Flea, Tick & Mosquito Treatment & Prevention | Dogs 21 - 55 lbs. | 6-Mo Supply - Advantage II Large Cat Vet-Recommended Flea Treatment & Prevention | Cats Over 9 lbs. | 6-Month Supply --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.com.pa/products/314573022-bayer-k9-advantix-ii-flea-tick-and-mosquito-prevention-x](https://www.desertcart.com.pa/products/314573022-bayer-k9-advantix-ii-flea-tick-and-mosquito-prevention-x) --- *Product available on Desertcart Panama* *Store origin: PA* *Last updated: 2026-11-03*