Evaluation of the efficacy of afoxolaner against Haemaphysalis longicornis on dogs.

A controlled study to assess the acaricidal efficacy of afoxolaner in dogs after a single oral administration was conducted against Haemaphysalis longicornis ticks. The study was characterized by a negative controlled randomized block design and included sixteen beagle dogs of both sexes. Starting two days before treatment, each dog was infested weekly with 50 ticks over 4 weeks. The number of live ticks was determined 48h after treatment and then 48h after each infestation. The mean dose of afoxolaner received by dogs was 3.0mg/kg (range: 2.5–3.1mg/kg). Afoxolaner rapidly eliminated pre-existing tick infestations (100% ticks killed within 48h of treatment) and controlled weekly re-infestations (91.9% prophylactic efficacy at Day 30).