Beaphar FIPROtec® COMBO Spot On for Large Dogs contains fipronil and the insect growth regulator S-methoprene. It not only kills adult fleas, ticks and biting lice, but also interrupts the flea life cycle, preventing any exposed eggs and/or larvae from developing in your home for up to eight weeks. FIPROtec® COMBO for Large Dogs kills adult fleas for up to eight weeks and ticks for up to four weeks. Suitable for dogs over 8 weeks of age and weighing 20-40kg. Suitable for use on pregnant and lactating bitches. Dogs who spend a lot of time outside are especially at risk from fleas and ticks. It is important to establish a regular flea control routine for dogs and the household.