Knubben-Schweizer Gabriela, Pfister Kurt
Prof. Dr. Gabriela Knubben-Schweizer, Klinik für Wiederkäuer mit Ambulanz und Bestandsbetreuung, Tierärztliche Fakultät der LMU München, Sonnenstraße 16, 85764 Oberschleißheim, E-Mail:
Tierarztl Prax Ausg G Grosstiere Nutztiere. 2017 Aug 10;45(4):244-251. doi: 10.15653/TPG-170287. Epub 2017 Aug 2.
Anthelmintic resistance of gastrointestinal nematodes in small ruminants, but also in cattle and horses, is now found worldwide. The reason for increasing anthelmintic resistance is, in particular, the extensive use of all the anthelmintic agents available on the market. A non-targeted use leads to the selection of naturally occurring resistance genes within parasite populations. The most practical method for evaluating the efficacy of an anthelmintic is the fecal egg-count reduction test. To reduce the rate of anthelmintic resistance development, the available active substances must be applied less and in a targeted manner. When applying targeted (selective) treatment, part of the herd is left untreated. Therefore, it is necessary to identify the animals that require treatment for health or economic reasons. To decide on anthelmintic treatment, findings can be collected from single animals or from a group of animals in a herd. To determine which groups of animals are to be treated within a herd (targeted treatment), pooled fecal samples (cattle and small ruminants), serum pepsinogen concentration (cattle), or Ostertagia ostertagi antibodies in the bulk milk (cattle) can be analyzed. For individual animal (targeted selective) treatment, criteria including fecal egg count (cattle and small ruminants), conjuctival color as an indicator for infection with Haemonchus contortus (FAMACHA, small ruminants), body condition in adult animals (small ruminants), weight gain in juvenile animals (cattle and small ruminants), and the consistency of the feces (small ruminants) are used. These decision criteria can also be combined to enhance the informative value. Furthermore, an efficacy test of the anthelmintics used should be performed regularly at the beginning of the pasture season. During the pasture season, a low infection pressure should be maintained by pasture management strategies. The goal of sustainable parasite management is the reduction of anthelmintic treatment while maintaining the productivity and health of the animals and thus a longer effectiveness of the available drugs.
目前在全球范围内都发现了小型反刍动物、牛和马体内胃肠道线虫的抗蠕虫药耐药性问题。抗蠕虫药耐药性增加的原因，尤其是市场上所有抗蠕虫药的广泛使用。无针对性的使用导致寄生虫种群中天然存在的耐药基因被选择。评估抗蠕虫药疗效最实用的方法是粪便虫卵计数减少试验。为了降低抗蠕虫药耐药性的发展速度，必须减少现有活性物质的使用并采用有针对性的方式。在进行有针对性的（选择性）治疗时，部分畜群不进行治疗。因此，有必要识别出于健康或经济原因需要治疗的动物。为了决定是否进行抗蠕虫药治疗，可以从单只动物或畜群中的一组动物收集数据。为了确定畜群中哪些动物群体需要治疗（有针对性的治疗），可以分析混合粪便样本（牛和小型反刍动物）、血清胃蛋白酶原浓度（牛）或批量牛奶中的奥斯特他线虫抗体（牛）。对于个体动物（有针对性的选择性）治疗，使用的标准包括粪便虫卵计数（牛和小型反刍动物）、作为捻转血矛线虫感染指标的结膜颜色（FAMACHA，小型反刍动物）、成年动物的体况（小型反刍动物）、幼年动物的体重增加（牛和小型反刍动物）以及粪便的稠度（小型反刍动物）。这些决策标准也可以结合起来以提高信息价值。此外，应在放牧季节开始时定期对抗蠕虫药进行疗效测试。在放牧季节，应通过牧场管理策略维持低感染压力。可持续寄生虫管理的目标是减少抗蠕虫药治疗，同时保持动物的生产力和健康，从而使现有药物的有效期更长。
