Lichtensteiger C A, DiPietro J A, Paul A J, Neumann E J, Thompson L
Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Illinois, Urbana 61802, USA.
Vet Parasitol. 1999 Apr 12;82(3):235-41. doi: 10.1016/s0304-4017(99)00018-7.
A study was conducted to investigate the persistent nematocidal activity of two avermectins against experimentally-induced infections of Ascaris suum in swine. Seventy-two nematode-free cross-bred pigs of similar bodyweight were randomly allotted to nine treatment groups of eight pigs each. Eight of the groups were treated with injectable solutions containing 300 microg of doramectin/kg (IM) or 300 microg of ivermectin/kg (SC) either 0 (same day), 7, 14, or 21 days prior to an oral challenge of 50000 embryonated A. suum eggs. The ninth group (control) was challenged in parallel without any avermectin treatment. At 41 or 42 days after challenge, pigs were euthanatized and adult and larval stages of A. suum were collected from the gastrointestinal tract of each pig and counted. Both avermectins significantly (P < 0.0002) reduced nematode counts when given on the day of challenge (0 days prior), and the efficacy was 100% and 97.5% for doramectin and ivermectin, respectively. Doramectin given 7 days prior to challenge significantly (P < 0.0001) reduced nematode counts, and the efficacy was 98.4%. For all other avermectin-treatment groups, nematode counts were not significantly reduced compared to those in control pigs. These data indicated that anthelmintic activity of ivermectin against A. suum persisted for less than 7 days and the activity of doramectin persisted for more than 7, but less than 14 days.
进行了一项研究，以调查两种阿维菌素对猪实验性感染猪蛔虫的持续杀线虫活性。72头体重相似的无线虫杂交猪被随机分配到9个处理组，每组8头猪。其中8个组在口服50000个猪蛔虫感染性虫卵进行攻毒前0天（同一天）、7天、14天或21天，分别用含300μg多拉菌素/千克（肌肉注射）或300μg伊维菌素/千克（皮下注射）的注射溶液进行处理。第九组（对照组）在没有任何阿维菌素处理的情况下进行平行攻毒。在攻毒后41或42天，对猪实施安乐死，并从每头猪的胃肠道收集猪蛔虫的成虫和幼虫阶段并计数。当在攻毒当天（前0天）给予两种阿维菌素时，线虫计数均显著降低（P<0.0002），多拉菌素和伊维菌素的疗效分别为100%和97.5%。在攻毒前7天给予多拉菌素显著降低了线虫计数（P<0.0001），疗效为98.4%。对于所有其他阿维菌素处理组，与对照猪相比，线虫计数没有显著降低。这些数据表明，伊维菌素对猪蛔虫的驱虫活性持续不到7天，而多拉菌素的活性持续超过7天，但不到14天。
