Frontline Plus For Large Dogs is a topical ectoparasitic treatment for dogs. This spot-on formula is indicated for use in 8 weeks and older puppies and dogs that weigh between 20 to 40kg. Frontline Plus Purple kills adult fleas and eliminates flea eggs and larvae to keep dogs protected throughout the month, thus preventing reinfestations. It effectively treats tick infestations. Frontline Plus for 20-40kg Dogs protects against paralysis ticks for two weeks and against brown dog ticks for four weeks.