Frontline Plus for Extra Large DogsFor dogs 8 weeks or older weighing 89 132 lb. No prescription required! Frontline Plus is a monthly topical flea and tick preventative for dogs. Frontline Plus kills 100% of adult fleas on your pet within 18 hours and 100% of all ticks and chewing lice within 48 hours. Frontline Plus contains an insect growth regulator, S methoprene, which kills flea eggs and larvae. It's effective against all stages of the brown dog tick, the American dog tick, the