Efficacy of afoxolaner against Ixodes scapularis ticks in dogs.

Efficacy of afoxolaner, a novel isoxazoline insecticide/acaricide, against Ixodes scapularis was evaluated in a laboratory study. One day prior to treatment, beagle dogs (n=16) were infested with 50 unfed wild adult ticks. Repeat infestations were performed weekly for four additional weeks. The number of live ticks remaining on each dog was determined 48 h after treatment and after each subsequent infestation. A single oral treatment with a dose approaching the minimum effective dose of afoxolaner (2.5mg/kg) eliminated the pre-existing infestations of I. scapularis ticks and controlled weekly re-infestations, with efficacy between 98% and 100% recorded until Day 23 and 94% at Day 30.