Frontline Plus Spot On Large Dog 20-40kg Used every four weeks, double action Frontline Plus Spot on Large Dog helps protect your dog from fleas & ticks as well as preventing flea eggs from hatching in your home.95% of a flea problem is in your pet's home environment as eggs, larvae & pupae (cocoons), so as well as killing fleas & ticks on your pet, Frontline Plus Spot on Large Dog contains active IGR technology to stop flea eggs from hatching & larvae developing in your home. This combination breaks the flea life cycle, offering enchanced protection for your pet & your home. Frontline Plus Spot on Large Dog: Kills fleas within 24 hours of contact with your pet. Kills ticks within 48 hours of contact with your pet. Kills biting lice. Inhibits the development of eggs & larvae. Protects your pet & your home. Frontline Plus Spot on Large Dog is suitable for puppies over 8 weeks that weigh at least 20kg & can be used during pregnancy & lactation. Each Frontline Plus Spot on Large Dog pipette contains 2.68ml