Advantage II for Dogs is a little bit cheaper than K9 Advantix II, so people can save money. If all you need is a very fast acting flea medication then I would certainly recommend Advantage. But if you want the extra protection then the price difference is minimal so the extra cost is worth it.
K9 Advantix II Topical Extra Large Dog Flea & Tick Treatment | Petco
We have been using K9 Advantix for years until they cam out with K9 Advantix II, and switched to it immediately. This product really works. I tried another (cheap) product a few years ago and within a week my boys had fleas, whereas they never ever had that problem with the Advantix. Needless to say, I immediately switched back and will not ever experiment again.
Quality of Ingredients
Haven't found anything better.
My boys have never suffered any ill effects from this product, however, it has been reported that some doge are deathly allergic to it. When trying it for the first time, keep a very close eye on your dog(s) for any signs of distress. If there are any, take them to the vet immediately.
K9 Advantix II for Dogs - Flea & Tick Meds | PetCareRx
K9 Advantix II is an excellent choice for people who live in areas with lots of mosquitoes and flies. If you see your dog being bothered by flying pests, then chances are you live in an area where K9 Advantix II can be your dog’s best friend. Does your dog live outside or spend a considerable amount of time outside? If so, I recommend trying K9 Advantix II. It kills fleas and ticks and can help control pesky flying bugs. I have used it on my dogs and was very happy with the results. I started using Advantix before I ever tried Frontline and I never had a problem with fleas and ticks, nor mosquitoes and flies. Eventually though, I decided to try Frontline because I found it cheaper than K9 Advantix and I found that it worked just the same. Also, I have cats in the house so that was really a deciding factor on why I use Frontline now. If I didn’t have cats then I would still be using Advantix.
Product - K9 Advantix II for Dogs X-Large Blue 2 Months