Little P R, Hodges A, Watson T G, Seed J A, Maeder S J
Veterinary Medicine Research & Development, Pfizer Animal Health, 45 Poplar Road, Parkville 3052, Australia.
N Z Vet J. 2010 Jun;58(3):121-9. doi: 10.1080/00480169.2010.67513.
To evaluate the efficacy and safety of the novel anthelmintic combination, derquantel-abamectin, against gastrointestinal nematode populations in sheep, under field-use conditions.
Controlled faecal egg count reduction tests (FECRT) were conducted in New Zealand in 14 trials, covering a range of geographic locations, farming enterprises, breeds, nematode populations, and anthelmintic-resistance profiles. Enrolled animals were naturally infected with mixed populations of gastrointestinal nematodes. All trials included a group treated with derquantel-abamectin, and a negative control group. Nine trials included additional groups each treated with a single- or dual-active oral reference anthelmintic, selected from albendazole, levamisole, albendazole-levamisole, ivermectin, abamectin and moxidectin. A total of 838 animals were enrolled across all trials, and were randomly allocated to treatment groups within blocks defined by faecal nematode egg counts (FEC) pretreatment. On Day 0 derquantel-abamectin was administered orally at 1 ml/5 kg bodyweight (2 mg/kg derquantel, 0.2 mg/ kg abamectin), and each reference anthelmintic was given at the recommended label dose. Faecal samples were collected on Day 14 (+/- 1 day), to determine the percentage reduction in mean FEC for each anthelmintic tested. Larval differentiation was also performed post-treatment, to estimate efficacy at the genus level. Animals were weighed on or before Day 0, and on Day 14 (+/- 1 day) in 13 trials.
The efficacy of derquantel-abamectin against mixed strongyle populations was > or =99.2%, based on the percentage reduction in geometric mean FEC. Nematodirus sp. was present in six trials at a level sufficient for efficacy calculations to be conducted; in all cases, the efficacy of derquantel-abamectin was 100%. In those trials where the efficacy of at least one reference anthelmintic was <95% against strongyles and/or Nematodirus sp., derquantel-abamectin was 100% effective. In five trials, the mean gain in bodyweight was significantly greater in the derquantel- abamectin group than the negative controls.
When administered orally at 1 ml/5 kg bodyweight, derquantel-abamectin is highly effective for the treatment of gastrointestinal nematodes in sheep, including populations of strongyles and Nematodirus sp. with resistance to one or more single- or dual-active anthelmintics. Derquantel-abamectin presents sheep producers with a unique opportunity to introduce a new class of anthelmintic to their nematode control programmes, with the added benefits offered by a combination anthelmintic.
在田间使用条件下，评估新型驱虫药组合——地克珠利-阿维菌素对绵羊胃肠道线虫种群的疗效和安全性。
2014年在新西兰进行了14项对照粪便虫卵计数减少试验（FECRT），试验涵盖了一系列地理位置、养殖企业、品种、线虫种群和驱虫药抗性情况。纳入的动物自然感染了胃肠道线虫混合种群。所有试验均包括一个接受地克珠利-阿维菌素治疗的组和一个阴性对照组。9项试验还包括额外的组，每组分别用一种单活性或双活性口服对照驱虫药进行治疗，这些对照驱虫药选自阿苯达唑、左旋咪唑、阿苯达唑-左旋咪唑、伊维菌素、阿维菌素和莫西菌素。所有试验共纳入838只动物，并根据预处理时粪便线虫虫卵计数（FEC）在区组内随机分配至各治疗组。在第0天，以1 ml/5 kg体重（2 mg/kg地克珠利，0.2 mg/kg阿维菌素）口服给予地克珠利-阿维菌素，每种对照驱虫药均按推荐的标签剂量给药。在第14天（±1天）采集粪便样本，以确定每种受试驱虫药的平均FEC降低百分比。治疗后还进行了幼虫分化，以估计属水平的疗效。在13项试验中，于第0天或之前以及第14天（±1天）对动物进行称重。
根据地克珠利-阿维菌素治疗组几何平均FEC的降低百分比，其对混合圆线虫种群的疗效≥99.2%。在6项试验中存在足够数量的细颈线虫属，可进行疗效计算；在所有情况下，地克珠利-阿维菌素的疗效均为100%。在那些至少一种对照驱虫药对圆线虫和/或细颈线虫属的疗效<95%的试验中，地克珠利-阿维菌素的疗效为100%。在5项试验中，地克珠利-阿维菌素组的平均体重增加显著高于阴性对照组。
当以1 ml/5 kg体重口服给药时，地克珠利-阿维菌素对绵羊胃肠道线虫具有高效，包括对一种或多种单活性或双活性驱虫药产生抗性的圆线虫和细颈线虫属种群。地克珠利-阿维菌素为绵羊养殖者提供了一个独特的机会，可将一类新型驱虫药引入其线虫控制方案，并带来复方驱虫药的额外益处。
