Armour J, Bairden K, Batty A F, Davison C C, Ross D B
Vet Rec. 1985 Feb 9;116(6):151-3. doi: 10.1136/vr.116.6.151.
Two studies are described which demonstrate the persistent activity of ivermectin injected subcutaneously into cattle at 200 micrograms/kg in preventing the establishment of induced infections with the gastrointestinal parasites Ostertagia ostertagi and Cooperia oncophora and the lungworm Dictyocaulus viviparus. These results indicated a reduction in mean worm count compared with the control group for O ostertagi of more than 99, 45 and 94 per cent with a seven, 14 or 21 day interval between treatment with ivermectin and the administration of infective larvae, respectively, in trial 1 and more than 99, more than 99 and 99 per cent at seven, 10 or 14 days, respectively, in trial 2. Corresponding values against C oncophora were 99, 0 and 45 per cent at seven, 14 and 21 days in trial 1 and more than 99, 84 and 31 per cent at seven, 10 and 14 days in trial 2. Against D viviparus, reduction in counts were more than 99, 98 and more than 99 per cent at seven, 14 and 21 days, respectively, in trial 1 and 100, 100 and 100 per cent at seven, 10 and 14 days, respectively, in trial 2. The relevance of these results to the build-up of infective larvae on pasture and infection in cattle is discussed.
本文描述了两项研究，这两项研究表明，以200微克/千克的剂量皮下注射伊维菌素对牛具有持续活性，可预防胃肠道寄生虫奥氏奥斯特线虫、牛库珀线虫和肺线虫胎生网尾线虫诱导感染的建立。这些结果表明，与对照组相比，奥氏奥斯特线虫的平均虫数减少，在试验1中，伊维菌素治疗与感染性幼虫给药之间分别间隔7、14或21天，减少率超过99%、45%和94%；在试验2中，分别在7、10或14天时减少率超过99%、超过99%和99%。试验1中，针对牛库珀线虫在7、14和21天时的相应值分别为99%、0和45%；试验2中，在7、10和14天时分别为超过99%、84%和31%。针对胎生网尾线虫，试验1中在7、14和21天时的虫数减少率分别超过99%、98%和超过99%；试验2中在7、10和14天时分别为100%、100%和100%。本文还讨论了这些结果与牧场上感染性幼虫积累及牛感染的相关性。
