A vet prescription is required for the medicine you have chosen frontline combo spot on is to be used against infestations with fleas ticks andor biting lice elimination of fleas ctenocephalides spp and insecticidal efficacy against new infestations with adult fleas persists for 8 weeks prevention of the multiplication of fleas by inhibiting the development of eggs ovicidal activity and larvae and pupae larvicidal activity originating from eggs laid by adult fleas for 8 weeks after