Prevents heartworm disease in dogs and puppies 6 weeks and older by eliminating the tissue stage of heartworm larvae (Dirofilaria immitis) for 30 days after infection; treats and controls ascarids (T. canis, T. leonina) and hookworms (A. caninum. U. stenocephala, A. braziliense). Active ingredients: ivermectin and pyrantel. Once-a-month dosing.