Lyons E T, Tolliver S C, Ionita M, Collins S S
Department of Veterinary Science, Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546-0099, USA.
Parasitol Res. 2008 Jul;103(2):287-91. doi: 10.1007/s00436-008-0966-8. Epub 2008 May 10.
Horse foals on five farms in Central Kentucky were used in field studies in 2007 evaluating activity of paste formulations of four compounds (fenbendazole-FBZ, ivermectin-IVM, oxibendazole-OBZ, and pyrantel pamoate-PRT) against internal parasites with emphasis on ascarids (Parascaris equorum). It has been well established the last few years that there is widespread resistance of P. equorum to ivermectin. The main purpose of the present research was to obtain current data on ascaridicidal activity of FBZ, OBZ, and PRT; also, to acquire further information on ascarid resistance to ivermectin. Additionally, data were documented on drug activity on small strongyles. Detection of ascarid and strongyle eggs in feces of foals was by a qualitative method (presence or absence) or a quantitative method (eggs per gram of feces). Strongyle eggs all were assumed to be from small strongyles. This is based on fecal cultures from horses on one farm and historic records from horses in this area on excellent deworming programs. A girth tape was used to estimate the body weight of each foal so that the appropriate dose rate of each drug could be given. Many of the foals were used in more than one cycle of treatments. Efficacy of the drugs, administered intraorally, was determined by calculating the average percentage reduction (% red.) of the number of foals passing eggs after vs. before treatment: (1) FBZ at 10 mg/kg was tested on four farms; 76 foals were examined, 50 with ascarid eggs (84% red.) and 62 with strongyle eggs (0% red.); (2) IVM at 200 microg/kg was tested on three farms; 58 foals were examined, 18 with ascarid eggs (0% red.) and 48 with strongyle eggs (100% red.); (3) OBZ at 10 mg/kg was tested on three farms; 181 foals were examined, 78 with ascarid eggs (94% red.) and 79 with strongyle eggs (0% red.); (4) PRT was tested on two farms, one farm at 1x (6.6 mg base/kg); 42 were foals examined, 16 with ascarid eggs (0% red.) and 33 with strongyle eggs (12% red.) and one farm at 2x (13.2 mg base/kg); 18 foals were examined, 13 with ascarid eggs (23% red.) and 15 with strongyle eggs (27% red.).
2007年，肯塔基州中部五个农场的马驹被用于实地研究，评估四种化合物（芬苯达唑 - FBZ、伊维菌素 - IVM、奥苯达唑 - OBZ和吡喹酮 - PRT）的膏剂对体内寄生虫的活性，重点是蛔虫（马副蛔虫）。在过去几年中已经明确，马副蛔虫对伊维菌素有广泛的耐药性。本研究的主要目的是获取关于FBZ、OBZ和PRT杀蛔虫活性的当前数据；此外，获取关于蛔虫对伊维菌素耐药性的更多信息。此外，还记录了药物对小型圆线虫的活性数据。通过定性方法（有无）或定量方法（每克粪便中的虫卵数）检测马驹粪便中的蛔虫和圆线虫卵。所有圆线虫卵都假定来自小型圆线虫。这是基于一个农场马匹的粪便培养以及该地区马匹关于良好驱虫方案的历史记录。使用围腰卷尺估计每匹马驹的体重，以便给予每种药物合适的剂量率。许多马驹用于不止一个治疗周期。通过计算治疗后与治疗前排出虫卵的马驹数量的平均减少百分比（% 减少）来确定口服给药药物的疗效：（1）在四个农场测试了10 mg/kg的FBZ；检查了76匹马驹，50匹有蛔虫卵（减少84%），62匹有圆线虫卵（减少0%）；（2）在三个农场测试了200 μg/kg的IVM；检查了58匹马驹，18匹有蛔虫卵（减少0%），48匹有圆线虫卵（减少100%）；（3）在三个农场测试了10 mg/kg的OBZ；检查了181匹马驹，78匹有蛔虫卵（减少94%），79匹有圆线虫卵（减少0%）；（4）在两个农场测试了PRT，一个农场以1倍剂量（6.6 mg碱基/kg）；检查了42匹马驹，16匹有蛔虫卵（减少0%），33匹有圆线虫卵（减少12%），另一个农场以2倍剂量（13.2 mg碱基/kg）；检查了18匹马驹，13匹有蛔虫卵（减少23%），15匹有圆线虫卵（减少27%）。
