Lufenuron, the other active ingredient, is an insect development inhibitor that breaks the flea life cycle by inhibiting egg development. Milbemycin oxime eliminates the tissue stage of heartworm larvae and the adult stage of hookworm, roundworm, and whipworm infestations.
Sentinel is the only monthly oral preventive that guards against heartworms, adult roundworms, adult hookworms, whipworms, and prevents the development of flea eggs. Sentinel Spectrum Large Dogs 51-100 lbs (22-45 kg) Chews 6 Pack