As responsible pet owners, we know how vital it is to keep our furry friends safe from pesky parasites. That's why we decided to try K9 Advantix II for our medium-sized dog, who falls right into the 11-20 lbs range. From the moment we applied the treatment, we were impressed by its ease of use and the peace of mind it brought. This vet-recommended formula not only targets fleas and ticks but also repels mosquitoes, which is a major plus during outdoor adventures. In our experience, the four-month supply stretched nicely, ensuring ongoing protection without constant reapplication. We appreciated its waterproof aspect, allowing our pup to enjoy those rainy walks without worry. Overall, K9 Advantix II has become our go-to solution for keeping our beloved dog pest-free.