Help prevent fleas and ticks from pestering your pal with Frontline Plus Flea and Tick Large Breed Dog Treatment! This treatment is fast-acting, long-lasting and waterproof, and helps control these pesky pests on extra-large-breed dogs and puppies eight weeks and older. The two tough pest control ingredients in this formula—fipronil and (S)-methoprene—work on killing both adult fleas, eggs and larvae, helping to prevent against further infestations. Stored in the oil glands of your dog’s skin, it provides flea and tick prevention for a full 30 days. No more bugs bugging your pup!