Efficacy of dinotefuran, permethrin and pyriproxyfen combination spot-on against Aedes aegypti mosquitoes on dogs

A spot-on formulation combining permethrin, dinotefuran and pyriproxyfen (Vectra 3D spot-on solution for dogs - one 10-25 kg pipette contains 196 mg dinotefuran, 1429 mg permethrin and 17 mg pyriproxyfen) was evaluated in adult Beagle dogs in a study designed to measure its efficacy to control Aedes aegypti (anti-feeding effect and mortality effect). The trial was performed according to Animal Welfare and Good Clinical Practice. Twelve dogs (five males and seven female, >3 years old, weighing 8.8-13.0 kg) were randomly allocated to treatment groups on pre-treatment mosquito counts: six dogs served as untreated controls, and six dogs were treated with the test formulation. Treatment consisted of applying a combination formulation to deliver at least 46.6 mg kg(-1) permethrin, 6.40 mg kg(-1) dinotefuran and 0.57 mg kg(-1) pyriproxyfen. The combination is designed to control fleas, ticks, sand flies and mosquitoes. Each dog was infested with approximately 100 adult unfed A. aegypti once before treatment (day 6) then at 1,7, 14, 21 and 28 days post-treatment. Counts and engorgement determination of dead and live mosquitoes were performed after 1h exposure period. In the treated group (group A), the repellency effect of the product based on engorgement status (anti-feeding effect), was 91.5%, 94%, 94.7%, 94% and 87% at 1, 7, 14, 21 and 28 days post-treatment. Mortality effect or insecticidal efficacy calculated at the end of the 1-h exposure was almost identical when calculated 24h after the 1-h exposure and remained above 93% until the end of the in-life phase. No adverse events were observed following treatment, including observations conducted 2, 4 and 24h after the last dog was treated.