Comparative Curative Efficacy of Two Spot On Formulations, Fipronil/Amitraz/ (S)-Methoprene and Imidacloprid/ Permethrin, on Two Tick Species in Dogs

摘要

This study compared the acaricidal efficacy of a new spot-on formulation of fipronil + amitraz + (S) methoprene (CERTIFEC~(TM)) and imidacloprid + permethrin (K9 AD-VANTIX~R) against a mixed infestation of Rhipicephalus sanguineus, the brown dog tick,and Dermacentor variabilis, the American dog tick. Twenty-four mixed-breed dogs (15 males and 9 females) weighing 10.7 to 24.9 kg and ranging from 1.4 to 13.8 years of age were divided into three groups of eight dogs. Group 1 was the untreated control group. On Day 0 dogs in Group 2 were treated with CERTIFECT and Group 3 dogs were treated with K9 ADVANTIX. All dogs were infested pre-treatment with 50 unfed R. sanguineus (Day -2) and 50 unfed D. variabilis (Day -1). The ticks were thumb counted 24 hours post-treatment and removed and counted 48 hrs post-treatment. The curative efficacy of CERTIFECT against R. sanguineus was 82.4% at 24 hrs and 99.1% at 48 hrs, while K9 ADVANTIX curative efficacy was 44.6% at 24 hrs and 75.8% at 48 hrs. Similarly, thepercent reduction of D. variabilis was 86.0% at 24 hrs and 100.0% at 48 hrs for CERTIFECT and 50.0% at 24 hrs and 75.0% at 48 hrs for K9 ADVANTIX~R. CERTIFECT was significantly (P < 0.05) more efficacious in reducing the number of R. sanguineus and D. variabilis both at 24 and 48 hours post-treatment when compared to K9 ADVANTIX.