Efficacy of the fipronil 10%+(S)-methoprene 9% combination against Rhipicephalus sanguineus in naturally infested dogs: speed of kill, persistent efficacy on immature and adult stages and effect of water.

This field trial was designed to test the efficacy, in terms of treatment and prevention, of the fipronil 10%+(S)-methoprene 9% combination against immature and adult stages of Rhipicephalus sanguineus in naturally infested dogs, and to assess the effect of a single plain water exposure. Twenty-four dogs of various age, sex, weight and coat length were divided into two homogeneous groups, treated (T) and control (C), and housed into twin outdoor kennels. Trial baseline was designed as day 0, when dogs from group T were treated with a commercial spot-on formulation of fipronil 10%+(S)-methoprene 9%, while subjects from group C were left untreated and served as control.