Keep your dog safe from dangerous and irritating insect pests with K9 Advantix topical flea treatment from Pet Supplies Delivered. K9 Advantix II Flea Control for Large Dogs protects dogs between 21 and 55 lbs and over 7 weeks old from fleas, ticks, mosquitoes, biting flies and lice even after shampooing. Two of the active ingredients in K9 Advantix II, imidacloprid and permethrin, kill pests on contact. The third ingredient, pyriporxyfen, impedes insect growth and kills all life stages of pests. Protect your dog with once-a-month applications of Advantix for dogs.