Frontline Plus Flea & Tick Spot Treatment for Large Dogs, 45-88 lbs, 3 Doses (3-mos. supply); Help protect your pup from pests with FRONTLINE Plus Flea & Tick Treatment for Large 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 large dogs weighing 45 to 88 pounds.