Ménard L
Can Vet J. 1994 May;35(5):289-92.
This study was undertaken to test the effect of clenbuterol, a smooth muscle relaxant, as an aid for the manual correction of bovine dystocias in a rural Quebec practice. The drug was given initially by intravenous coccygeal or jugular injection at a dose of 0.6 micrograms-0.8 micrograms/kg of body weight to parturient cows affected with fetal malpresentations (n = 37), malpostures (n = 112), or uterine torsions (n = 70). These cases comprised 32% (219/688) of the manually corrected dystocias encountered in cattle during the trial. Ease provided for obstetrical maneuvers of different types of dystocias was the evaluation criteria used in this report. The drug's myometrial relaxant effect made corrections easier for the veterinarian, and shorter and less traumatic for the dam. The success rates achieved for vaginal corrections and delivery of uterine torsions were 84% (76/91) and 77% (70/91), respectively. Other recorded benefits included the need for less frequent use of epidural anesthesia and a significantly lower incidence of retained fetal membranes (chi 2 = 11.18, p < 0.001). No adverse reactions were observed at any time. Clenbuterol proved to be a useful drug for manual correction of dystocias in cattle.
本研究旨在测试平滑肌松弛剂克伦特罗在魁北克农村地区辅助人工矫正牛难产的效果。对患有胎儿胎位不正（n = 37）、姿势异常（n = 112）或子宫扭转（n = 70）的临产母牛，最初通过尾静脉或颈静脉注射给药，剂量为0.6微克 - 0.8微克/千克体重。这些病例占试验期间牛人工矫正难产病例的32%（219/688）。本报告采用的评估标准是为不同类型难产的产科操作提供的便利程度。该药物的子宫肌层松弛作用使兽医的矫正操作更容易，对母牛来说时间更短且创伤更小。阴道矫正和子宫扭转分娩的成功率分别为84%（76/91）和77%（70/91）。其他记录的益处包括减少硬膜外麻醉的使用频率以及胎膜残留的发生率显著降低（χ² = 11.18，p < 0.001）。在任何时候均未观察到不良反应。克伦特罗被证明是一种辅助人工矫正牛难产的有用药物。
