Efficacy of a single administration of afoxolaner (NexGard®) or fipronil plus permethrin (Frontline® Tri-Act) against Hyalomma marginatum ticks in dogs

Abstract

This study was conducted to assess the acaricidal efficacy of afoxolaner (NexGard®, Boehringer Ingelheim), and fipronil - permethrin (Frontline® Tri-Act, Boehringer Ingelheim) administered once to dogs experimentally infested with Hyalomma marginatum ticks. Twenty-four Beagle dogs were randomly allocated based on a pre-treatment H. marginatum infestation to an untreated control group, a NexGard® or a Frontline® Tri-Act treated groups. Treatments were administered once on Day 0 as per the products' labels. For the efficacy evaluation, dogs were experimentally infested with 30 adult H. marginatum ticks on Days -2, 7, 28 and 36. In-situ counts were performed at 48 h post-treatment on Day 2 and post-infestations on Days 9, 30 and 38. Ticks were removed and counted at 72 h post-treatment on Day 3 and after each tick infestation on Days 10, 31 and 39. The numbers of live ticks counted in the treated groups were significantly different than in the control group at all time-points (p ≤ 0.0006). The efficacy was at least 97% after 48 h, and at least 99% after 72 h for both treatments. In this study both afoxolaner and fipronil/permethrin formulations demonstrated a high efficacy against adult H. marginatum ticks in treated dogs for at least five weeks.

Keywords: Afoxolaner; Dogs; Fipronil; Hyalomma marginatum; Permethrin; Tick.