Revolution PLUS for Cat offers broad external and internal parasite protection for a month against: -Fleas (Ctenocephalides felis. Kills adult fleas within 6 hours and cleans up flea eggs and flea larvae in the environment. Kills fleas before they can lay eggs, interrupting the flea life cycle. Decreases signs of flea allergy dermatitis (FAD). -Paralysis ticks (Ixodes holocyclus). A single dose is highly effective against paralysis ticks in cats for up to 35 days. -Intestinal Roundworm and Hookworm (Toxocaracati & Ancyclostomatubaeforme) -Biting lice (Felicolasubrostratus) -Heartworm (Dirofilariaimmitis). Heartworm in cats is often overlooked as clinical symptoms can be vague but can include sudden death. -Ear mites (Otodectescynotis)