Efficacy of a Single Oral Administration of Afoxolaner Alone or in Combination with Milbemycin Oxime against &amp;lt;i&amp;gt;Ixodes hexagonus&amp;lt;/i&amp;gt; Ticks in Dogs

W Lebon,P Dumont,M Servonnet,D Larsen,F Beugnet

doi:10.4236/ojvm.2019.94004

Abstract

The efficacy of afoxolaner (NexGard® and NexGard Spectra®, Boehringer-Ingelheim), administered once orally at the minimum recommended dose, was assessed in dogs experimentally infested with Ixodes hexagonus ticks. The study was a blinded, negative controlled clinical efficacy study using a randomized block design. Twenty-four Beagle dogs, 12 females and 12 males were enrolled. Dogs were randomly allocated either to the negative control group, or to one of the two treated groups. Infestations were performed with 50 adult I. hexagonus ticks on Days-2, 7 and 28. On Day 0, dogs in groups 2 and 3 were treated with NexGard® (afoxolaner) or NexGard Spectra® (afoxolaner + milbemycin oxime), respectively. Tick counts were conducted 48 hours after treatment (Day 2) and 48 hours after each subsequent infestation (Days 9 and 30). In both treated groups, afoxolaner was 100% effective against existing infestations (p < 0.0001). Regarding the re-infestations, the efficacy of afoxolaner was 100% on Day 9 for both products, 96.5% and 100% on Day 30 for NexGard® and NexGard Spectra® respectively. NexGard® and NexGard Spectra® chewable tablets administered once orally at the minimum recommended dose were highly effective against I. hexagonus infestations for the 4 weeks duration of the study.

Highlights

IntroductionTicks are quite common ectoparasites, with over 800 species described world-
This experimental dose confirmation study was conducted to assess the efficacy of afoxolaner (NexGard or NexGard Spectra chewables) against Ixodes hexagonus, commonly called the hedgehog tick
NexGard is an afoxolaner-based palatable formulation marketed for the monthly treatment of fleas, ticks, demodicosis and sarcoptic mange in dogs

Summary

Introduction

Ticks are quite common ectoparasites, with over 800 species described world-. The clinical significance of tick infestation in dogs is based on direct pathogenic effects (e.g. skin reactions and anemia in case of heavy burdens of ticks), but mainly linked to them as potential vectors. Widespread and endemic in Europe, Ixodes species are known vectors of several pathogens of animal and human significance (e.g. Borrelia burgdorferi, Anaplasma phagocytophilum, Tick-Borne Encephalitis virus...). The most common tick species parasitizing dogs in Western, Central and Eastern Europe is Ixodes ricinus, called the wood tick. Other Ixodes species such as Ixodes hexagonus, and Ixodes canisuga, may be found in dogs but their prevalence is lower [2]-[9]

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Conclusion