Summary Reintroduction of endangered species to natural habitat is considered as an important tool for conservation. The effect of drug management on captive population of reintroduced species is largely neglected. Decreased drug efficacy could pose a substantial threat to health of animals. More importantly, captive population without proper drug administration could act as transmission medium of resistance nematodes to wild population, making it important to delay the occurrence of drug resistance in captive population. Ivermectin have been used in captive Przewalski’s horse (Equus ferus przewalskii) to eradicate intestinal parasitic nematodes annually, while no available studies describing the drug efficacy in the recent ten years. Here, fecal egg counts pre- and post-treatment were performed with ivermectin through individual trace. Both large and small strongyles were identifi ed by larval culture. The fecal egg count reduction was almost 100% based on egg counting data of 448 samples from 13 Przewalski’s horses. Feces of two Przewalski’s horses were sampled for successive 20 days. Eggs per gram feces usually increased dramatically at the period of 1 – 2 post-treatment days and declined persistently to 0.0 within 15 days. A sustained high ivermectin efficacy against neither Parascaris equorum nor strongyles was indicated, which can be partly explained by the low deworm frequency.

中文翻译：

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伊维菌素对寄生于圈养普氏野马 (Equus ferus przewalskii) 的原发线虫的药物疗效经过十年的年度治疗

总结 将濒危物种重新引入自然栖息地被认为是保护的重要工具。药物管理对重新引入物种的圈养种群的影响在很大程度上被忽视了。药物功效的降低可能对动物的健康构成重大威胁。更重要的是，没有适当给药的圈养种群可以作为抗性线虫向野生种群的传播媒介，这使得延缓圈养种群耐药性的发生具有重要意义。伊维菌素每年都被用于圈养普氏野马（Equus ferus przewalskii）以根除肠道寄生线虫，而近十年来没有研究描述其药效。在这里，通过个体追踪用伊维菌素进行处理前和处理后的粪便鸡蛋计数。大和小的圆线虫都通过幼虫培养来识别。根据来自 13 匹普氏野马的 448 个样本的卵计数数据，粪便卵计数减少了几乎 100%。连续 20 天对两匹普氏野马的粪便进行采样。每克粪便中的虫卵数通常在治疗后 1-2 天期间急剧增加，并在 15 天内持续下降至 0.0。表明伊维菌素对 Parascaris eqorum 和圆线虫都没有持续的高功效，这可以部分解释为低驱虫频率。每克粪便中的虫卵数通常在治疗后 1-2 天期间急剧增加，并在 15 天内持续下降至 0.0。表明伊维菌素对 Parascaris eqorum 和圆线虫都没有持续的高功效，这可以部分解释为低驱虫频率。每克粪便中的虫卵数通常在治疗后 1-2 天期间急剧增加，并在 15 天内持续下降至 0.0。表明伊维菌素对 Parascaris eqorum 和圆线虫都没有持续的高功效，这可以部分解释为低驱虫频率。