AgResearch, Grasslands Research Centre, Private Bag 11008, Palmerston North 4442, New Zealand.
Department of Agriculture and Food Western Australia, 444 Albany Highway, Albany, WA 6330, Australia.
Vet Parasitol. 2014 Jul 30;204(1-2):44-54. doi: 10.1016/j.vetpar.2013.12.022. Epub 2013 Dec 31.
In many countries the presence of anthelmintic resistance in nematodes of small ruminants, and in some cases also in those infecting cattle and horses, has become the status quo rather than the exception. It is clear that consideration of anthelmintic resistance, and its management, should be an integral component of anthelmintic use regardless of country or host species. Many years of research into understanding the development and management of anthelmintic resistance in nematodes of small ruminants has resulted in an array of strategies for minimising selection for resistance and for dealing with it once it has developed. Importantly, many of these strategies are now supported by empirical science and some have been assessed and evaluated on commercial farms. In sheep the cost of resistance has been measured at about 10% of the value of the lamb at sale which means that losses due to undetected resistance far outweigh the cost of testing anthelmintic efficacy. Despite this many farmers still do not test for anthelmintic resistance on their farm. Many resistance management strategies have been developed and some of these have been tailored for specific environments and/or nematode species. However, in general, most strategies can be categorised as either; identify and mitigate high risk management practices, maintain an anthelmintic-susceptible population in refugia, choose the optimal anthelmintic (combinations and formulations), or prevent the introduction of resistant nematodes. Experiences with sheep farmers in both New Zealand and Australia indicate that acceptance and implementation of resistance management practices is relatively easy as long as the need to do so is clear and the recommended practices meet the farmer's criteria for practicality. A major difference between Australasia and many other countries is the availability and widespread acceptance of combination anthelmintics as a resistance management tool. The current situation in cattle and horses in many countries indicates a failure to learn the lessons from resistance development in small ruminants. The cattle and equine industries have, until quite recently, remained generally oblivious to the issue of anthelmintic resistance and the need to take pre-emptive action. In Australasia, as in other countries, a perception was held that resistance in cattle parasites would develop very slowly, if it developed at all. Such preconceptions are clearly incorrect and the challenge ahead for the cattle and equine industries will be to maximise the advantages for resistance management from the extensive body of research and experience gained in small ruminants.
在许多国家，小反刍动物线虫中驱虫剂耐药性的存在已成为常态，在某些情况下，牛和马线虫中也存在这种情况。很明显，无论国家或宿主物种如何，都应将驱虫剂耐药性及其管理考虑为驱虫剂使用的一个组成部分。多年来，人们一直在研究了解小反刍动物线虫中驱虫剂耐药性的发展和管理，从而制定了一系列策略来最大程度地减少耐药性的选择，并在耐药性产生后加以处理。重要的是，其中许多策略现在都得到了实证科学的支持，并且已经在商业农场中进行了评估和评估。在绵羊中，耐药性的成本约为出售羔羊价值的 10%，这意味着由于未检测到耐药性而造成的损失远远超过了检测驱虫剂功效的成本。尽管如此，许多农民仍然不在其农场中检测驱虫剂耐药性。已经开发了许多耐药性管理策略，其中一些策略已针对特定环境和/或线虫物种进行了调整。但是，通常大多数策略都可以分为以下几类：识别和减轻高风险管理实践，在避难所中维持驱虫剂敏感种群，选择最佳驱虫剂（组合和配方），或防止耐药线虫的引入。新西兰和澳大利亚的绵羊农民的经验表明，只要有明确的需要，并且推荐的实践符合农民的实用性标准，接受和实施耐药性管理实践就相对容易。澳大拉西亚与许多其他国家之间的一个主要区别是，组合驱虫剂作为一种耐药性管理工具的可用性和广泛接受程度。许多国家的牛和马的现状表明，它们没有从小反刍动物中耐药性发展的经验中吸取教训。牛和马产业直到最近才普遍对驱虫剂耐药性问题以及采取先发制人行动的必要性一无所知。在澳大拉西亚，与其他国家一样，人们认为牛寄生虫的耐药性发展非常缓慢，如果有的话。这种先入为主的观念显然是不正确的，牛和马产业面临的挑战将是从小反刍动物中获得的广泛研究和经验中，为耐药性管理最大限度地利用优势。
