Bello Hornblenda Joaquina Silva, Lins José Gabriel Gonçalves, de Albuquerque Ana Cláudia Alexandre, Ferreira Gabriel Badial, Amarante Mônica Regina Vendrame, do Amarante Alessandro Francisco Talamini
School of Veterinary Medicine and Animal Science, UNESP - São Paulo State University, Botucatu, Brazil.
Institute of Biociences, UNESP - São Paulo State University, Botucatu, Brazil.
Front Vet Sci. 2022 Jan 18;8:798942. doi: 10.3389/fvets.2021.798942. eCollection 2021.
The sheep nasal bots is parasite of the nasal cavities and sinuses of small ruminants causing oestrosis, one of the most frequent parasitic diseases in sheep and goats. The widely use of ivermectin and closantel by the sheep breeders in the treatment and prophylaxis of gastrointestinal nematodes resulted in widespread cases of anthelmintic resistance. However, there is no report about cases of with drug-resistance. In this study, we evaluated the prophylactics and therapeutic effects of both antiparasitics in sheep with natural infestation. The trial was carried out from early December 2019 to March 2020, with 30 crossbred males lambs allocated into three groups of 10 animals each: control (without treatment), treated with ivermectin (0.2 mg/kg subcutaneously) and treated with closantel (10 mg/kg orally). The animals were kept together grazing the same pasture area. The treatment groups were drenched in two occasions 70 days apart: on 5th December 2019 and on 13th February 2020. On 19th March 2020, all lambs were slaughtered. The lamb heads were removed and sectioned along their longitudinal and sagittal axis to search for larvae. Recovered larvae were counted and identified according to their developmental stage (L1, L2, and L3). Seven of the control lambs were infested with larvae ranging from six to 17 larvae (11.6 mean infestation intensity). All recovered larvae from control group were intact and active. Three animals treated with ivermectin had larvae (1-3 larvae), however they were dead and in degeneration. The animals treated with closantel did not have any larvae. The clinical suggestive signs of oestrosis were scarce over the experimental period. The averages of daily weight gain were similar ( > 0.05) among groups. Closantel and ivermectin had high efficacy against oestrosis and parasitism did not hinder the performance of lambs.
羊鼻蝇蛆是小型反刍动物鼻腔和鼻窦的寄生虫，可引起羊狂蝇蛆病，这是绵羊和山羊中最常见的寄生虫病之一。绵羊养殖者广泛使用伊维菌素和氯氰碘柳胺钠来治疗和预防胃肠道线虫，导致驱虫抗性病例广泛出现。然而，尚无关于耐药病例的报告。在本研究中，我们评估了这两种抗寄生虫药对自然感染羊的预防和治疗效果。试验于2019年12月初至2020年3月进行，将30只杂交雄性羔羊分为三组，每组10只动物：对照组（未治疗）、用伊维菌素治疗（皮下注射0.2mg/kg）和用氯氰碘柳胺钠治疗（口服10mg/kg）。这些动物一起在同一牧区放牧。治疗组在相隔70天的两个时间点进行灌药：2019年12月5日和2020年2月13日。2020年3月19日，所有羔羊被屠宰。取下羊头并沿其纵轴和矢状轴切开以寻找幼虫。对回收的幼虫进行计数，并根据其发育阶段（L1、L2和L3）进行鉴定。对照组的7只羔羊感染了6至17条幼虫（平均感染强度为11.6条）。对照组回收的所有幼虫均完整且活跃。三只接受伊维菌素治疗的动物有幼虫（1至3条幼虫），但它们已死亡并处于退化状态。接受氯氰碘柳胺钠治疗的动物没有任何幼虫。在实验期间，羊狂蝇蛆病的临床提示症状很少。各组之间的日增重平均值相似（P>0.05）。氯氰碘柳胺钠和伊维菌素对羊狂蝇蛆病有很高的疗效，寄生虫感染并未妨碍羔羊的生长性能。
