Flea, Tick & Mosquito Showdown: K9 Advantix II 4-Mo Supply Tested (11-20 lbs) We've put the K9 Advantix II 4-month supply to the test, and it's delivered consistent results for our furry friends in the 11-20 lbs range. This vet-recommended treatment combines strength and simplicity-easy to apply, invisible on the skin, and effective against parasites that thrive in warm weather. Our dogs showed no signs of irritation, and the scent was mild enough to avoid overwhelming their senses. The convenience of a 4-month supply means fewer trips to the vet or pet store, making it ideal for busy households. While it's not the cheapest option on the market, its reliability and long-lasting protection justify the cost. We've seen it keep ticks at bay during outdoor adventures and prevent mosquito bites in areas with high infestation. For those seeking a balanced approach between efficacy and ease, this product stands out as a dependable choice-though we'd still recommend double-checking local pest trends for optimal use.