Assessment of the prophylactic speed of kill of Frontline Tri-Act® against ticks (Ixodes ricinus and Rhipicephalus sanguineus) on dogs

The objective of the study was to assess the speed of kill of a single topical treatment with a combination of fipronil and permethrin (Frontline Tri-Act(®)/Frontect(®)) against experimental infestations of Ixodes ricinus and Rhipicephalus sanguineus ticks on dogs. In this parallel group designed, randomised, single centre, controlled efficacy study, 16 healthy adult dogs were allocated to two groups: 8 dogs were treated with the topical combination on Day 0 and the other 8 dogs served as untreated controls. Each dog was exposed in a crate to 100 I. ricinus (50 females, 50 males) and 50 R. sanguineus (25 males, 25 females) on Days 2, 7, 14, 21 and 28. Ticks were counted in situ at 6 and 12 h after exposure and removed at 24 h after exposure. Frontline Tri-Act(®) was effective (≥90%) against both R. sanguineus and I. ricinus tick infestations at 6, 12 and 24 h after exposure, from 2 to 28 days after treatment. This is the first time that a topical ectoparasiticide has demonstrated a preventive killing effect against these two tick species in 6 h for a full month.