评估口服氟雷拉纳（博来恩）对美洲钝眼蜱和（广义）血红扇头蜱若虫的疗效。

Evaluation of oral fluralaner (Bravecto) for efficacy against nymphs of Amblyomma americanum and Rhipicephalus sanguineus (sensu lato).

机构信息

Department of Veterinary Pathobiology, Oklahoma State University, College of Veterinary Medicine, Stillwater, Oklahoma, 74078, USA.

Merck Animal Health, De Soto, Kansas, 66018, USA.

出版信息

Parasit Vectors. 2020 Jun 18;13(1):315. doi: 10.1186/s13071-020-04179-y.

DOI:10.1186/s13071-020-04179-y

PMID:32552774

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7302130/

Abstract

BACKGROUND

Amblyomma americanum and Rhipicephalus sanguineus (sensu lato) nymphs commonly feed on and transmit pathogens to dogs (Canis familiaris). Control of immature and adult tick life stages is necessary to fully protect animals. We evaluated efficacy of oral fluralaner (Bravecto) against induced infestations with A. americanum and R. sanguineus (s.l.) nymphs on dogs in two experiments.

METHODS

In each experiment, 10 dogs were administered oral fluralaner chewable tablets one time on Day 0 at a targeted minimum dose of 25 mg/kg body weight and 10 dogs remained non-treated controls. Dogs were infested with two groups of 50 A. americanum nymphs and two groups of 50 R. sanguineus (s.l.) nymphs on Days -1, 6, 28, 56 and 84. At 48 h and 72 h post-infestation, nymphs were collected from dogs, assessed as live or dead, and enumerated into categories defining attachment and engorgement status. Fluralaner efficacy was determined in separate analyses against all live nymphs and against live-fed nymphs, i.e. live nymphs that were attached to dogs at the time of collection and/or were engorged. Fluralaner was considered effective when mean numbers of live ticks were reduced in fluralaner-treated dogs by ≥ 90%.

RESULTS

Fluralaner efficacy against all live and live-fed A. americanum nymphs in the first experiment was > 94% on all collection days. Efficacy against all live R. sanguineus (s.l.) nymphs in the first experiment was > 96% on all collection days excluding the 48 h counts for infestations on Days 28 (83.7%), 56 (82.9%) and 84 (86.7%); efficacy against live-fed R. sanguineus (s.l.) nymphs was > 95% on all 48 h/72 h count days. Fluralaner efficacy against all live A. americanum nymphs in the second experiment was > 93% on all collection days for 8 weeks excluding the 48 h count for infestation on Day 56 (87.8%); efficacy against live-fed A. americanum nymphs was > 91% on all count days for 8 weeks. Efficacy against all live R. sanguineus (s.l.) nymphs in the second experiment was > 91% on all 72 h collection days except for infestations on Days 28 (76.8%) and 56 (86.3%); efficacy against live-fed R. sanguineus (s.l.) nymphs was 100% on all 72 h count days.

CONCLUSIONS

A single administration of oral fluralaner to dogs is effective against A. americanum and R. sanguineus (s.l.) nymphs for up to 12 weeks.

摘要

背景

孤星蜱和血红扇头蜱（广义）若虫通常以犬（Canis familiaris）为食，并传播病原体。控制不成熟和成年蜱的生命阶段对于充分保护动物是必要的。我们评估了口服氟雷拉纳（Bravecto）对犬进行诱导感染孤星蜱和血红扇头蜱（广义）若虫的疗效，该实验分两部分进行。

方法

在每个实验中，10 只犬在第 0 天经口给予口服氟雷拉纳咀嚼片，目标最小剂量为 25mg/kg 体重，10 只犬作为非治疗对照。犬在第-1、6、28、56 和 84 天分别接受两组 50 只孤星蜱若虫和两组 50 只血红扇头蜱（广义）若虫的感染。在感染后 48 小时和 72 小时，从犬身上收集若虫，评估其死活状态，并根据附着和饱食状态将其分类计数。在单独的分析中，以所有活蜱和活食蜱的数量来确定氟雷拉纳的疗效，即活蜱在收集时附着在犬身上和/或已饱食。当氟雷拉纳治疗犬的活蜱数量减少≥90%时，即可认为氟雷拉纳具有疗效。

结果

在第一个实验中，所有活的和活食的孤星蜱若虫的氟雷拉纳疗效在所有采集日均≥94%。第一个实验中，所有活的血红扇头蜱（广义）若虫的氟雷拉纳疗效在所有采集日均≥96%，除了第 28 天（83.7%）、第 56 天（82.9%）和第 84 天（86.7%）的 48 小时计数；所有活食的血红扇头蜱（广义）若虫的疗效在所有 48 小时/72 小时计数日均≥95%。在第二个实验中，所有活的孤星蜱若虫的氟雷拉纳疗效在 8 周的所有采集日均≥93%，除了第 56 天的 48 小时计数（87.8%）；所有活食的孤星蜱若虫的疗效在 8 周的所有计数日均≥91%。在第二个实验中，所有活的血红扇头蜱（广义）若虫的氟雷拉纳疗效在所有 72 小时采集日均≥91%，除了第 28 天（76.8%）和第 56 天（86.3%）；所有活食的血红扇头蜱（广义）若虫的疗效在所有 72 小时计数日均为 100%。