Pivoto Felipe Lamberti, Machado Fabricio Amadori, Anezi-Junior Paulo Afonso, Weber Augusto, Cezar Alfredo Skrebsky, Sangioni Luis Antonio, Vogel Fernanda Silveira Flores
Department of Preventive Veterinary Medicine, Universidade Federal de Santa Maria (UFSM), Av. Roraima 1000, Prédio 44, 97105-900, Santa Maria, RS, Brazil.
Parasitol Res. 2014 Jun;113(6):2303-10. doi: 10.1007/s00436-014-3885-x. Epub 2014 Apr 18.
The aim of this study was to compare the liveweight gain of lambs, infected by multidrug-resistant nematodes, treated by conventional schemes of helminth control or using a schedule based on fecal egg count reduction test (FECRT). The flock was selected after a FECRT (experiment 1) which revealed a parasite population resistant to benzimidazoles, imidazothiazoles, macrocyclic lactones (ivermectin), salicylanilides, nitrophenols, and organophosphates. Despite the parasite resistance to ivermectin (an avermectin), the moxidectin (a milbemycin) was effective against the gastrointestinal nematodes (PR > 90%). In experiment 2, 48 suckling lambs were distributed in four randomized blocks (G1, G2, G3, and G4) by previous body weighings. G1 was kept as untreated control; G2 was treated following a FECRT-based schedule with drugs chosen based on fecal analysis (first drench with moxidectin, second drench with a combination of moxidectin and levamisole, and third drench with praziquantel, an anti-cestode drug); G3 and G4 received three drenches with ivermectin or disophenol, respectively. Body weighings and fecal analysis of these lambs were performed every 2 weeks over a 98-day period. An effective control of gastrointestinal nematodes was obtained with two nematicidal drenches following the FECRT-based schedule of treatments. On the other hand, eggs per gram of feces (EPG) counts were no different among untreated control, G3, and G4. Lambs treated using the FECRT-based schedule had the greatest liveweight gain among the groups tested. Additionally, liveweight gain was no different among the groups G3, G4, and G1. The FECRT-based schedule of anthelmintic treatments was beneficial regarding productivity and sustainability of helminth control in lambs infected by multidrug-resistant nematodes.
本研究的目的是比较感染多重耐药性线虫的羔羊，采用传统蠕虫控制方案或基于粪便虫卵计数减少试验（FECRT）的方案进行治疗后的体重增加情况。在一次FECRT（实验1）后选择了该羊群，结果显示寄生虫群体对苯并咪唑、咪唑噻唑、大环内酯类（伊维菌素）、水杨酰苯胺、硝基酚和有机磷酸盐具有抗性。尽管寄生虫对伊维菌素（一种阿维菌素）具有抗性，但莫西菌素（一种米尔倍霉素）对胃肠道线虫有效（PR＞90%）。在实验2中，通过先前的体重称量将48只哺乳羔羊随机分为四个区组（G1、G2、G3和G4）。G1作为未处理对照；G2按照基于FECRT的方案进行治疗，根据粪便分析选择药物（第一次灌服莫西菌素，第二次灌服莫西菌素和左旋咪唑的组合，第三次灌服吡喹酮，一种抗绦虫药物）；G3和G4分别接受三次伊维菌素或双酚灌服。在98天的时间里，每2周对这些羔羊进行一次体重称量和粪便分析。按照基于FECRT的治疗方案进行两次杀线虫灌服后，有效控制了胃肠道线虫。另一方面，未处理对照、G3和G4之间每克粪便中的虫卵（EPG）计数没有差异。在测试的各组中，采用基于FECRT方案治疗的羔羊体重增加最大。此外，G3、G4和G1组之间的体重增加没有差异。对于感染多重耐药性线虫的羔羊，基于FECRT的驱虫治疗方案在蠕虫控制的生产力和可持续性方面是有益的。
