Help protect your pup from pests with FRONTLINE Plus Flea & Tick Treatment for Medium Dogs. This flea and tick control treatment is specially formulated to kill adult fleas, flea eggs, flea larvae, chewing lice and ticks, including ticks that may transmit Lyme disease. It’s made with two active ingredients—fipronil and (S)-methoprene—to help disrupt the flea life cycle and prevent future infestations. Each fast-acting topical application offers 30 days of full-body, waterproof protection by depositing into your dog’s sebaceous glands. FRONTLINE Plus for Dogs is paw-fect for medium dogs and puppies ages eight weeks and older weighing 23 to 44 pounds.