Protect your cat with the #1 name in flea and tick protection.* FRONTLINE? Plus flea and tick prevention for cats and kittens is a long-lasting, fast-acting, waterproof flea and tick treatment proven to kill adult fleas, flea eggs, flea larvae, chewing lice and ticks. This flea and tick treatment kills ticks that may transmit Lyme disease. FRONTLINE Plus for Cats has been trusted by pet owners for over 20 years.** This month-long treatment is made for cats and kittens eight weeks or older, weighing 1.5 pounds and greater. Made with two active ingredients, fipronil and (S)-methoprene, this treatment breaks the flea life cycle by killing adult fleas as well as the eggs and larvae and prevents new infestations. One fast-acting topical application protects for a full 30 days.