Effipro spot on for very large dogs for the treatment of flea ctenocephalides spp and tick dermacentor reticulatus infestations insecticidal efficacy against new infestations with adult fleas persists for up to 8 weeks the product has a persistent acaricidal efficacy for up to 4 weeks against ticks rhipicephalus sanguineus ixodes ricinus dermacentor reticulatus if ticks of some species rhipicephalus sanguineus and ixodes ricinus are present when the product is applied all the tick