Comfortis Plus Blue Pack is a top Vet-recommended treatment for Large Dogs. It prevents Flea infestations, controls Flea Allergy dermatitis, and Treats Intestinal worms (Hookworms, Roundworms, Whipworms). It Also Prevents Heartworm disease. Buy Comfortis Plus 40 to 60 lbs now for the lowest prices, with free shipping and reward points. Hurry and save!