(Bayer) Advantage Multi for Dogs Heartworm Topical Solution is a monthly topical solution to control fleas, heartworms, hookworms, roundworms and whipworms. Advantage Multi for Dogs kills adult fleas, prevents heartworm disease, and is indicated for the treatment of flea infestations, and for treatment and control of hookworms, roundworms and whipworms. Advantage Multi for Dogs contains imidacloprid and moxidectin. Apply topically once per month. Approved for dogs and puppies at least 3 lbs and 7 weeks of age. Imidacloprid and moxidectin.