Muniz R A, Coronado A, Anziani O S, Sanavria A, Moreno J, Errecalde J, Goncalves L C
Animal Health Group, Pfizer Inc., Groton, CT 06340, USA.
Vet Parasitol. 1995 Jul;58(4):327-33. doi: 10.1016/0304-4017(94)00730-z.
Three studies were conducted in Latin America--one in Venezuela, one in Argentina and one in Brazil--using a common protocol to investigate the efficacy of a single subcutaneous injection of doramectin in the prevention and control of Cochliomyia hominivorax infestations in castrated cattle. In each study, two groups of 20-28 animals each were allocated to a treated (T1) or to a control (T2) group on the basis of body weights. Animals of T1 received doramectin at 200 micrograms kg-1 (1 ml per 50 kg) and animals of T2 received saline solution at 1 ml per 50 kg of live weight. After treatment all cattle were castrated surgically. Animals were examined on treatment day and at 2, 4, 6 and 12 days post-treatment. At each observation day, the presence of C. hominivorax infestations was recorded. Doramectin was 100% effective in the prevention and control of screwworm strikes in castrated cattle exposed to continuous field infestations of C. hominivorax in tropical and subtropical areas of Latin America. Over the 12 day duration of the studies, 85%, 60% and 65% of animals in the control groups had infested wounds in Venezuela, Argentina and Brazil, respectively. Affected animals required repeated therapeutic treatment, whereas none of the doramectin-treated cattle were infested (P < 0.0001). A high proportion of the castration wounds in doramectin-treated cattle had the presence of characteristic C. hominivorax eggs but none developed into larvae. There were no clinical signs of adverse reactions to treatment in any of the three studies.
在拉丁美洲开展了三项研究——一项在委内瑞拉，一项在阿根廷，一项在巴西——采用通用方案调查皮下注射一次多拉菌素对去势牛预防和控制嗜人锥蝇感染的效果。在每项研究中，根据体重将两组各20 - 28头动物分别分配到治疗组（T1）或对照组（T2）。T1组动物接受200微克/千克（每50千克1毫升）的多拉菌素，T2组动物接受每50千克活重1毫升的盐溶液。治疗后所有牛都进行了手术去势。在治疗当天以及治疗后第2、4、6和12天对动物进行检查。在每个观察日，记录嗜人锥蝇感染情况。在拉丁美洲热带和亚热带地区，暴露于嗜人锥蝇持续田间感染的去势牛中，多拉菌素在预防和控制螺旋蝇叮咬方面的有效率为100%。在研究的12天期间，委内瑞拉、阿根廷和巴西对照组中分别有85%、60%和65%的动物出现感染伤口。受影响的动物需要反复进行治疗，而接受多拉菌素治疗的牛均未感染（P < 0.0001）。接受多拉菌素治疗的牛中，很大比例的去势伤口有嗜人锥蝇特征性卵，但无一发育成幼虫。在三项研究中的任何一项中，均未出现治疗不良反应的临床症状。
