This medicine is used to treat and prevent flea (Ctenocephalides felis) infestations. Fleas on the dog's body are destroyed within one day of treatment. One treatment prevents flea infestation for four weeks. It can be used as part of a treatment plan for flea allergy dermatitis. This medicine has a permanent acaricidal effect against tick infestation (four weeks against Rhipicephalus sanguineus, Ixodes ricinus and three weeks against Dermacentor reticulatus). Ticks that are already attached to the dog may not be killed within two days of treatment and may remain attached and visible. Therefore, it is recommended that ticks already present on the dog be removed during treatment to prevent them from getting caught and sucking blood.