School of Veterinary Medicine, Department of Medicine and Epidemiology, University of California, Davis, CA 95616, USA,
Wildlife Investigations Laboratory, California Department of Fish and Wildlife, Rancho Cordova, CA 95670, USA.
J Zoo Wildl Med. 2020 Nov;51(3):631-642. doi: 10.1638/2019-0197.
Sarcoptic mange epidemics can have long-lasting impacts on susceptible wildlife populations, potentially contributing to local population declines and extirpation. Since 2013, there have been 460 reported cases of sarcoptic mange in an urban population of endangered San Joaquin kit foxes () in Bakersfield, CA, with many of them resulting in fatality. As part of a multifaceted response to mitigate mange-caused mortalities and reduce this conservation threat, a 2-yr randomized field trial was conducted to assess the efficacy of long-acting flumethrin collars against sarcoptic mange in kit foxes. Thirty-five kit foxes living in a high-density population on a college campus were captured, examined, administered selamectin, and each fox randomly assigned to either receive a flumethrin collar placed within a VHF radio collar or a VHF radio collar without flumethrin. The survival and mange-infestation status of study animals was monitored via radio telemetry, remote cameras, and periodic recapture examinations and compared among treated and control kit foxes using a Cox proportional hazards model. The average time to onset of mange for treated kit foxes (176 days) was similar to controls (171 days) and treatment with flumethrin did not significantly reduce mange risk for all kit foxes. Kit foxes that had a mild mange infestation at the beginning of the study were four times more likely to develop mange again, regardless of flumethrin treatment, compared with kit foxes that had no signs at initial recruitment. This study demonstrates an approach to evaluating population-level protection and contributes to the limited literature on efficacy, safety, and practicality of acaricides in free-ranging wildlife.
疥螨病流行疫情可能会对易感染的野生动物种群产生持久影响，从而导致局部种群数量下降和灭绝。自 2013 年以来，加利福尼亚州贝克斯菲尔德市的濒危圣华金狐种群中已有 460 例报告的疥螨病病例，其中许多导致死亡。作为缓解疥螨引起的死亡率和减少这种保护威胁的多方面措施的一部分，进行了为期 2 年的随机现场试验，以评估长效氟虫腈项圈对狐的疗效。在大学校园高密度的狐栖息地中捕获了 35 只狐，对它们进行了检查、给予了塞拉菌素，并将每只狐随机分配到接受带有 VHF 无线电项圈的氟虫腈项圈或不带氟虫腈的 VHF 无线电项圈。通过无线电遥测、远程摄像头和定期重新捕获检查来监测研究动物的生存和疥螨感染状况，并使用 Cox 比例风险模型比较处理和对照狐的情况。治疗狐开始出现疥螨病的平均时间（176 天）与对照组相似（171 天），氟虫腈治疗并未显著降低所有狐的疥螨病风险。与初始招募时没有迹象的狐相比，在研究开始时轻度感染疥螨的狐再次感染疥螨的可能性高四倍，无论是否接受氟虫腈治疗。本研究展示了一种评估种群保护水平的方法，并为评估自由放养野生动物的杀螨剂功效、安全性和实用性的有限文献做出了贡献。
