Várady M, Petersen M B, Bjørn H, Nansen P
Danish Centre for Experimental Parasitology, Department of Veterinary Microbiology, Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
Int J Parasitol. 1996 Apr;26(4):369-74. doi: 10.1016/0020-7519(96)00007-0.
Anthelmintic efficacies of 3 different doses of ivermectin (IVM) were evaluated in 3 isolates of nodular worms in pigs. An isolate of Oesophagostomum quadrispinulatum (OQ) was recently obtained from a commercial farm where poor efficacy of IVM at the recommended dose (300 micrograms.kg-1 body weight) was detected. On this farm, IVM had been used for treatment of sows twice yearly for 6 years. Two other isolates, an O. dentatum (OD) and a mixed Oesophagostomum dentatum and Oesophagostomum quadrispinulatum isolate (ODQ) were obtained from a farm where anthelmintics had never been used. Efficacies of IVM against adult worms of the OQ-isolate at dose rates of 150, 300 and 600 micrograms.kg-1 body weight ranged from 40.5-78.6%. Efficacies against larval stages (L3 and L4) were superior. Efficacies against the OD-isolate were 88.7, 96.1 and 99.6%, respectively. In the ODQ-isolate the efficacies of IVM against adult stages furnished similar results. In conclusion, the efficacy of IVM against O. dentatum was high but against both isolates of O. quadrispinulatum poorer. This suggests that IVM is intrinsically less effective against O. quadrispinulatum and therefore not indicative of acquisition of anthelmintic resistance in the OQ-isolate.
在猪的3种结节线虫分离株中评估了3种不同剂量伊维菌素（IVM）的驱虫效果。最近从一个商业农场获得了一种四棘食道口线虫（OQ）分离株，在该农场检测到推荐剂量（300微克·千克体重）的IVM疗效不佳。在这个农场，IVM已用于母猪的治疗，每年两次，持续6年。另外两种分离株，一种齿状食道口线虫（OD）和一种齿状食道口线虫与四棘食道口线虫混合分离株（ODQ），是从一个从未使用过驱虫药的农场获得的。IVM对OQ分离株成虫在150、300和600微克·千克体重剂量率下的驱虫效果为40.5%-78.6%。对幼虫阶段（L3和L4）的效果更好。对OD分离株的驱虫效果分别为88.7%、96.1%和99.6%。在ODQ分离株中，IVM对成虫阶段的驱虫效果提供了类似的结果。总之，IVM对齿状食道口线虫的效果很高，但对两种四棘食道口线虫分离株的效果较差。这表明IVM对四棘食道口线虫本质上效果较差，因此不能表明OQ分离株获得了驱虫抗性。
