PDF(Sci-hub)
Abstract：
Parasite control in foals is complicated by the concurrent presence of biologically diverse parasites with differing levels of anthelmintic resistance. Several combination anthelmintic products are available for use in horses, but information on their efficacies against important equine parasites is scarce. Two trials were performed in New Zealand during 2008 and 2011 on four different farms with substantially different anthelmintic treatment histories. The first trial evaluated the efficacy of an ivermectin/praziquantel/oxibendazole combination, a single active oxibendazole, and a single-active macrocyclic lactone (ML) in 49 foals located on three farms. The second trial evaluated two combination anthelmintic products and three single-active ML products and enrolled a total of 110 foals on three farms. Foals in the second trial were allocated to one of six anthelmintic treatment groups; oxfendazole/pyrantel embonate, pyrantel embonate/ivermectin/praziquantel, ivermectin/praziquantel, abamectin/praziquantel, moxidectin/praziquantel, and a placebo-treated control. In both trials, foals were monitored monthly prior to treatment, and fecal egg counts (FECs) of Parascaris spp., strongylid, and Strongyloides westeri were determined. A \"rolling enrolment\" process was implemented whereby foals were systematically allocated to a treatment group and treated with the corresponding anthelmintic following the first appearance of Parascaris spp. eggs in the faeces. A generalised linear model was used to evaluate the effect of farm and treatment on Day14 FEC (ln) for each parasite. Three different FECR calculation methods were employed as follows; i) FECR(T) pre and post treatment ii) FECR (C) in the treated group compared with control, and iii) FECR (P) pre- and post- treatment in the treated and control groups. Across both trials, treatment with ML single active products failed to achieve >95% reduction in Parascaris spp. FEC on two of three farms. The pyrantel embonate/oxfendazole and ivermectin/ praziquantel/oxibendazole combinations demonstrated full efficacy against Parascaris spp. This is in contrast to the anti-strongylid efficacies determined, where the pyrantel embonate/oxfendazole combination and single active oxibendazole had reduced efficacy on one farm, while the macrocyclic lactones generally had good efficacy. Strongyloides egg counts were sporadic in both trials, and allowed limited insight into anthelmintic efficacy. The study illustrated the importance of keeping an untreated or placebo-treated control group in studies evaluating anti-Parascaris efficacy and it demonstrated the utility of a rolling enrolment procedure, where foals are enrolled over the course of a defined period of time. Furthermore, the study demonstrated the value of a farm specific FECR monitoring programme and the complexity of parasite control in foals, where combination anthelmintic products can be employed to target multiple species of parasites.
摘要：
由于同时存在具有不同驱虫抗性水平的生物多样性寄生虫，因此小马驹中的寄生虫控制变得复杂。有几种组合驱虫产品可用于马匹，但是关于它们对重要马寄生虫的功效的信息很少。2008年和2011年期间，在新西兰的四个不同农场进行了两项试验，这些农场的驱虫治疗历史大不相同。第一项试验评估了伊维菌素/吡喹酮/昔苯达唑联合用药的疗效，单一的活性昔苯达唑，和位于三个农场的49只小马驹中的单活性大环内酯（ML）。第二项试验评估了两种联合驱虫产品和三种单一活性ML产品，并在三个农场共招募了110只小马驹。第二项试验中的马驹被分配到六个驱虫药治疗组之一；奥芬达唑/吡喃酮，pyrantelembonate/伊维菌素/吡喹酮,伊维菌素/吡喹酮,阿维菌素/吡喹酮,莫西丁/吡喹酮,和安慰剂治疗的对照。在两个试验中,治疗前每月对马驹进行监测，和寄生虫的粪便卵数（FECs）。,strongylid,确定了龙圆线虫。实施了“滚动登记”过程，将小马驹系统地分配给治疗组，并在Parascis属首次出现后使用相应的驱虫药进行治疗。粪便中的鸡蛋。使用广义线性模型来评估每种寄生虫的农场和治疗对Day14FEC（ln）的影响。采用以下三种不同的FECR计算方法；i）治疗前后的FECR（T）ii）治疗组与对照组相比的FECR（C），和iii)治疗组和对照组治疗前后的FECR(P)。在两个试验中，用ML单一活性产品治疗未能实现parascarisspp的>95%减少。FEC在三个农场中的两个。pyrantel碳酸酯/奥芬达唑和伊维菌素/吡喹酮/奥昔苯达唑的组合对寄生虫具有完全的疗效。这与确定的抗强直性功效相反，其中pyrantelembonate/oxfendazole组合和单一活性oxybendazole在一个农场的功效降低，而大环内酯类一般有较好的疗效。在两项试验中，类圆线虫的卵数都是零星的，并允许对驱虫药疗效的有限了解。该研究说明了在评估抗寄生虫疗效的研究中保持未经治疗或安慰剂治疗的对照组的重要性，并证明了滚动登记程序的实用性。在规定的时间段内注册小马驹。此外，该研究证明了农场特定的FECR监测计划的价值以及小马驹中寄生虫控制的复杂性，其中组合驱虫药产品可用于靶向多种寄生虫。
