丙硫苯咪唑驱除绵羊胃肠道线虫的试验

丙硫苯咪唑驱除绵羊胃肠道线虫的试验宗泽群汪作民石剑华斯钦昭日格１昭日格图２内蒙古赤峰市畜牧兽医科学研究所赤峰０２４０３１；１巴林右旗幸福之路苏木兽医站；２巴林右旗巴彦他拉苏木兽医站据调查，赤峰地区六月龄以上的放牧绵羊胃肠道线虫感染率达１００％，强度在...     

用丙硫苯咪唑检测羊线虫抗药性的体外虫卵孵化试验

为探讨用丙硫苯咪唑进行体外虫卵孵化试验检测羊线虫对苯并咪唑类药物的抗药性,对23个羊场的25份田间样品用丙硫苯咪唑和噻苯咪唑进行了虫卵孵化试验并与先前减卵试验（faecal egg count re-duction test,FECRT）的结果比较。结果表明,25份样品中,丙硫苯咪唑和噻苯咪唑对受检虫卵的半数致死量（LD50）均值分别为0.050 1和0.054 0μg/mL,差异不显著。FECRT检测有抗药性的4个羊场,75%的样品对丙硫苯咪唑和噻苯咪唑的LD50均值均在0.1μg/mL以上,只有1个羊场的的LD50值分别为0.068 9μg/mL（丙硫苯咪唑）和0.071 2μg/mL（噻苯咪唑）。检测为可疑的2个羊场,其样品的LD50值为0.04～0.07μg/mL;FECRT检测敏感的蠕虫群体的LD50均在0.04μg/mL以下。此外,丙硫苯咪唑用纯的二甲基亚砜溶解和稀释后于4℃保存7 d,LD50值变化不大,提示药效无明显下降,而保存14 d后药效有下降趋势。     

灭虫丁与丙硫苯咪唑驱除山羊胃肠道线虫对比试验

灭虫丁对牛羊寄生线虫有良好的驱虫作用，目前国内广泛应用的驱虫药丙硫苯咪唑也被公认为良好的驱除家畜寄生线虫的药物，为了便于使用者择优选用，我们进行了两种药物驱除羊寄生线虫的比较试验。     

用虫卵孵化试验对江苏羊场线虫抗药性的检测

用虫卵孵化试验对江苏羊场线虫抗药性进行了检测,测得其虫卵经半数抑制量ＥＤ５０为０．０６３３μｇ／ｍＬ丙硫苯咪唑,是敏感株的２０余倍。该方法操作方便,快速,结果客观,敏感,可以用于检测虫株抗药性的发生和抗药性动态变化规律分析,为寄生虫病防止抗药提供有效依据。     

河北省坝上地区绵羊消化道线虫对丙硫苯咪唑抗药性的检测

目的　为了查明绵羊消化道线虫对丙硫苯咪唑的抗药性。方法　应用粪便虫卵减少试验 (FECRT)对河北省坝上地区绵羊消化道线虫的抗药性进行了检测。结果　应用 5 m g/ kg丙硫苯咪唑对 5组绵羊进行驱虫的虫卵减少率分别为 4 3.9% ,38.4 6 % ,4 9.0 9% ,37.6 3%和 4 3.35 % ,驱净率分别为 2 0 % ,15 % ,15 % ,2 5 %和 10 %。结论　根据 FECRT 95 %置信域小于 90 % ,表明试验羊对该药有抗药性     

用虫卵孵化试验对江苏某羊场线虫抗药性的检测

用虫卵孵化试验对江苏某羊场线虫抗药性进行了检测,测得其虫卵孵化半数抑制量ＥＤ５０为０．０６３３μｇ／ｍＬ丙硫苯咪唑,是敏感株（０．００２６μｇ／ｍＬ丙硫苯咪唑）的２０余倍。该方法操作方便、快速、结果客观、敏感,可以用于检测虫株抗药性的发生和抗药性动态变化规律分析,为寄生虫病防止抗药性提供有效依据。     

三种药物驱治绵羊寄生虫及消化道线虫排卵规律的研究

几年来,根据我市绵羊体内外寄生虫种类调查结果,表明我市绵羊体内外寄生虫共有29种,主要危害虫种是胃肠道线虫,其它虫种次之.依据这一客观规律,笔者因地制宜地选择灭虫丁、丙硫苯咪唑、盐酸左旋咪唑三种药物进行了驱虫试验,旨在观察驱虫效果,并测定消化道线虫排卵规律.     

山羊胃肠道线虫调查及防治效果观察

为了摸清山羊胃肠道线虫的感染种类、感染强度及感染率进行了本次调查,结果发现感染率高达１００％,感染强度大,ＥＰＧ达３４１６,最多可达６９００,且混合感染严重,最多达７种,最少也有４种,选用阿福丁、左旋咪唑及丙硫苯咪唑进行驱虫,并观察了增重效果。结果,三种药物对山羊胃肠道线虫成虫均有好的驱杀作用,投药第７天时平均虫卵减少率分别为１００％、９０．６３％及１００％,对幼虫的作用以阿福丁为优;羊驱虫与否的     

多拉菌素等三种药物驱除绵羊胃肠道线虫效果观察

通过选取多拉菌素等三种驱虫药物对绵羊胃肠道线虫进行驱除。结果表明,三种药物对绵羊胃肠道线虫均有明显效果,平均驱虫率依次为多拉菌素组（98.7%）〉伊维菌素组（94.3%）〉丙硫苯咪唑组（82%）。比较后确定适合我市推广的新型驱虫药物为多拉菌素注射液。     

左旋咪唑和丙硫苯咪唑对绵羊寄生虫的驱虫结果及分析

左旋咪唑和丙硫苯咪唑是广谱、高效、低毒的驱虫新药，根据报导对各种畜禽的寄生虫有很好的驱虫效果，我们为了掌握这两种驱虫新药在本地对绵羊寄生虫的驱虫效果和最佳的驱虫剂量，对今后这两种药的推广应用提供科学依据，故进行本试验。     

A survey of the prevalence of emerging macrocyclic lactone resistance and of benzimidazole resistance in sheep nematodes in the lower North Island of New Zealand

AIM: To investigate the occurrence of emerging macrocyclic lactone (ML) resistance and of resistance to benzimidazole anthelmintics on a number of sheep farms in the North Island of New Zealand.

METHODS: On commercial sheep farms (n=30) in the Taihape district in the North Island of New Zealand, 30 animals were randomly allocated to one of two equal-sized groups and treated with either half of the recommended dose rate of ivermectin (half of 0.2 mg/kg), or with the full recommended dose rate of oxfendazole (4.5 mg/kg). The ivermectin treatment only was used on a further six properties. Faecal egg counts, accompanied by pooled larval cultures, were conducted on all samples at the time of treatment and 7–10 days later.

RESULTS: Resistance, as indicated by a <95% faecal egg count reduction (FECR) in both instances, was found to oxfendazole on 13/30 (43%) farms and to a half dose of ivermectin on 12/36 (33%) properties. For oxfendazole, such resistance was found to involve all six nematode genera whereas for ivermectin it was almost entirely restricted to Ostertagia and Cooperia infections.

CONCLUSIONS: These results indicate that emerging ML resistance may be more common on sheep farms in New Zealand than is generally realised. They also suggest that the half-dose ivermectin faecal egg count reduction test (FECRT) may offer some very practical benefits for parasite control by providing early warning of developing resistance to ML drenches and by signalling the possible imminent failure of these at their therapeutic dose rates. The sensitivity and reliability of this procedure may be further enhanced by the inclusion of larval cultures.     

The efficacy of an albendazole-medicated block in controlling sheep nematodes in Xinjiang Province,north-west China

Medicated feed-blocks containing 2 mg/kg albendazole were fed for 12 days to ewe-lambs naturally infected with nematode worms in north-west China. The cumulative total average intake of albendazole was 15 mg/kg body weight. This treatment was compared with a single oral drench of 15 mg/kg albendazole and with no treatment. Both albendazole treatments were 99% effective in reducing the total strongyle egg counts. The medicated block was 100% effective in reducing the total trichostrongylid worm count, although only 86.4% of the sheep consumed an adequate amount. The single drench was 97% effective. Under the management conditions available to sheep herders in the northern provinces of China, albendazole-medicated feed-blocks used at strategic times could effectively control trichostrongylid nematodes.     

Clinical field study to evaluate the efficacy and safety of the amino-acetonitrile derivative, monepantel, compared with registered anthelmintics against gastrointestinal nematodes of sheep in Australia

Objective   To determine the efficacy of monepantel, a developmental compound from the amino-acetonitrile derivative class of anthelmintics, against field infections of gastrointestinal nematodes in sheep.
Procedures   Comparisons of efficacy (using standard faecal worm egg count reduction tests) and safety (on the basis of visual observations) were made in a large-scale field study in Australia, between groups of sheep treated with either an oral solution of monepantel or a registered anthelmintic. The sheep were naturally infected with the major gastrointestinal nematode genera present in Australia.
Results   The post-treatment efficacy results for monepantel were: at 7 days (±1 day) efficacy was >98%; at 14 days (±1 day) it was generally close to or >99%; and at 21 days (±1 day) efficacy was consistently >99%. A high proportion of the targeted nematode populations were confirmed as being resistant to one or more of the currently available anthelmintic classes.
Conclusions   Monepantel when used under field conditions at a minimum dose rate of 2.5 mg/kg was highly effective against mixed-genus natural field infections of the major gastrointestinal nematode genera including Haemonchus , Teladorsagia ( Ostertagia ), Trichostrongylus , Nematodirus , Chabertia and Oesophagostomum . This result included efficacy against some populations resistant to the currently available broad-spectrum anthelmintics. Few Cooperia spp. were present to allow confirmation of efficacy against this genus. On no occasion after treatment did any commercial anthelmintic-treated groups have significantly lower faecal egg counts than the monepantel-treated groups. Monepantel was safe for the target animals and human operators when used in a field situation.     

阿苯达唑对波尔山羊消化道线虫的药效试验

为了观察阿苯达唑片对波尔山羊消化道线虫的驱除效果,探讨其对波尔山羊线虫病治疗的最佳剂量,将150只波尔山羊随机分成5组,其中设阿苯达唑7.5、15、30 mg/kg作为试验组,同时设左旋咪唑7.5 mg/kg作为药物对照组和阳性对照组,给药前后检查虫卵和虫体,计算虫卵转阴率、虫卵减少率和驱虫率,最后进行统计分析。结果显示,高剂量组和中剂量组的虫卵转阴率、虫卵减少率和驱虫率均显著高于低剂量组和盐酸左旋咪唑片对照组(P0.01),而高剂量组与中剂量组的虫卵转阴率、虫卵减少率和驱虫率差异不显著。15 mg/kg的阿苯达唑片对波尔山羊线虫的驱除效果安全。     

A comparison of plasma metabolite levels in goats and sheep during continuous low-level administration of fenbendazole

Plasma levels of fenbendazole (FBZ) and its sulphoxide (OFZ) and sulphone (FBZ.SO₂) metabolites were measured in goats and sheep during low-level administration of FBZ given by intraruminal infusion or formulated into a urea-molasses feed supplement block (UMB). In experiment 1, 6 goats and 6 sheep were offered UMB containing 0.5 g FBZ/kg (MUMB) and individual block consumption was measured daily for 18 days. In experiment 2, some of the same animals (n=4 for each species) received FBZ by intraruminal infusion at 1, 1.5 and 3 mg/kg liveweight per day for 7 days at each dosage. FBZ, OFZ and FBZ.SO levels were determined in plasma collected every 3 days in experiment 1 and on days 4, 5 and²6 of each infusion period in experiment 2. In both experiments, higher equilibrium levels were observed for the three metabolites in sheep than in goats. Significant linear relationships were observed between the daily FBZ dosages and the plasma levels of the three metabolites in both species. The regression coefficients were significantly higher in sheep than in goats for FBZ and OFZ but not for FBZ.SO₂, and they were also significantly higher during MUMB administration than during infusion for all three metabolites in both species. FBZ is a suitable anthelmintic for incorporation into a MUMB formulation for use in livestock production systems where responses to molasses urea supplementation have been demonstrated and gastrointestinal parasitism impairs productivity. The results indicate that target dose rates for goats should be 0.75 mg/kg per day compared with 0.5 mg/kg per day for sheep.Abbreviations ANOVA analysis of variance - FBZ fenbendazole - FBZ.SO₂ fenbendazole sulphone - HPLC high-performance liquid chromatography - MUMB urea-molasses feed supplement block containing 0.5 g fenbendazole/kg - OFZ fenbendazole sulphoxide - UMB urea-molasses feed supplment block     

The Effects of a Controlled-Release Albendazole Capsule (Proftril-Captec) on Parasitism in Grazing Corriedale Ewes in the Nyandarua District of Kenya

Munyua, W.K., Githigia, S.M., Mwangi, D.M., Kimoro, C.O. and Ayuya, J.M., 1997. The effects of a controlled-release albendazole capsule (Profitril-Captec) on parasitism in grazing Corriedale ewes in the Nyandarua district of Kenya. Veterinary Research Communications, 21 (2), 85-99The effects of intraruminal sustained-release capsules (IRSRCs) on parasitism in grazing Corriedale ewes were investigated over a period of 119 days (4 June-30 September 1993) using 40 ewes aged approximately 2 years and randomly divided into two groups of 20 ewes each. Each of the ewes in the treatment group received an IRSRC while the controls were left untreated. The groups were placed on adjacent 2.5-acre paddocks obtained by subdividing a 5.0-acre permanent pasture which had previously been grazed by young untreated sheep, so exposing both groups of ewes to a similar challenge from a contaminated paddock. The faecal egg counts, herbage larval counts and worm burdens of the major gastrointestinal parasites of sheep were significantly reduced by the use of the IRSRC. These parasitological effects were reflected in the increased live weight gains and heavier fleeces of the IRSRC-treated ewes. The control ewes required occasional salvage treatments during the trial period and the herbage on their paddock was heavily contaminated with infected larvae, reflected in the high worm burdens in the control ewes necropsied at the end of the trial and in tracer sheep introduced into the paddocks during the initial (day 30), interim (day 58) and final (day 89) stages of the experiment. Most capsules were exhausted within 95 days of administration, leading to a rise in the count of eggs per gram in the faeces in the treated group towards the end of the study.