Hartz UltraGuard Plus Foaming Flea & Tick Shampoo for Cats 5.25oz Contains both an insecticide to kill adult fleas & ticks and an Insect Growth Regulator (IGR) to kill flea eggs before they hatch Designed to kill both the adult fleas and their eggs and larvae, thereby breaking the flea lifecycle The shampoo will also break the tick life-cycle by killing adult ticks including the Deer tick which may carry Lyme disease For use on kittens 12 weeks of age and older