Advantage Extra Large Blue is for dogs over 25kg. It is for the treatment and prevention of fleas (Ctenocephalides spp) on extra large dogs. Larval flea stages are killed in the surroundings of Advantage treated pets. It reduces the incidence of flea allergy Dermatitis and controls lice (Trichodectes canis, Linognathus setosus). One application lasts for a month. It is convenient and easy to apply.