Maingi N, Otieno R O, Gichohi V M, Weda E H
Department of Veterinary Pathology, Microbiology & Parasitology, Faculty of Veterinary Medicine, University of Nairobi, Kenya.
Onderstepoort J Vet Res. 2002 Sep;69(3):229-35.
The effectiveness of anthelmintic treatments given 3 weeks after the onset of rains to control gastrointestinal nematodes in sheep in the highlands of central Kenya was investigated. The study was carried out on a farm situated approximately 85 km north west of Nairobi in Nyandarua District of central Kenya. In May 1999, 35 Corriedale ram lambs aged between 8 and 10 months were eartagged, weighed and given albendazole at 3.8 mg/kg body mass. The animals were then allocated to three treatment groups. Three weeks after onset of both the short and long rains' season in November 1999 and April 2000 respectively, lambs in groups 1 and 2 were dewormed. Lambs in group 1 were given closantel at 10 mg/kg body mass in November and closantel plus albendazole at 3.8 mg/kg body mass in April. Lambs in group 2 were given albendazole at 3.8 mg/kg body mass on both occasions, while lambs in group 3 were maintained as the untreated controls. Nematode eggs per gram of faeces (epg) for lambs in the control group were significantly higher (P < 0.05) than in the treated groups beginning from November, when the strategic treatments started. The levels of epg did not differ significantly between the two treated groups. Body mass for the treated groups was significantly higher (P< 0.05) than for the control group from January 2000 until the experiment was terminated. The rainfall received in the study area in 2000 during the long rain season was inadequate and only occurred for a short period. The amount of herbage on pastures was therefore not adequate and all the study animals started losing mass from June 2000 until the experiment was terminated. The cumulative mass gain and amount of wool produced by the treated lambs during the study period did not differ significantly. There was therefore no difference in using either of the two drugs. It is concluded that, strategic anthelmintic treatments of sheep at the start of the wet season in the highlands of central Kenya is effective in controlling gastrointestinal nematodes. To prevent high levels of re-infection during the season of the long rains (April to June), it is recommended that, during this season, a second treatment be given 5-6 weeks after the first one or at the start of the dry season.
对肯尼亚中部高地绵羊在雨季开始3周后进行驱虫治疗以控制胃肠道线虫的效果进行了研究。该研究在肯尼亚中部尼亚丹鲁瓦区、内罗毕西北约85公里处的一个农场开展。1999年5月，35只8至10月龄的考力代公羔羊被戴上耳标、称重，并按3.8毫克/千克体重给予阿苯达唑。然后将这些动物分为三个治疗组。分别在1999年11月和2000年4月短雨季和长雨季开始3周后，对第1组和第2组的羔羊进行驱虫。第1组的羔羊在11月按10毫克/千克体重给予氯氰碘柳胺，4月按3.8毫克/千克体重给予氯氰碘柳胺加阿苯达唑。第2组的羔羊在这两个时间点均按3.8毫克/千克体重给予阿苯达唑，而第3组的羔羊作为未治疗的对照组。从11月开始进行策略性治疗时起，对照组羔羊每克粪便中的线虫卵（epg）显著高于治疗组（P<0.05）。两个治疗组之间的epg水平没有显著差异。从2000年1月到实验结束，治疗组的体重显著高于对照组（P<0.05）。2000年长雨季期间研究区域的降雨量不足，且只持续了很短一段时间。因此牧场的牧草量不足，所有研究动物从2000年6月到实验结束体重都开始下降。研究期间治疗组羔羊的累积体重增加和产毛量没有显著差异。因此，使用这两种药物中的任何一种都没有区别。得出的结论是，在肯尼亚中部高地雨季开始时对绵羊进行策略性驱虫治疗对控制胃肠道线虫是有效的。为防止在长雨季（4月至6月）期间再次感染水平过高，建议在这个季节，在第一次治疗后5至6周或旱季开始时进行第二次治疗。
