Ede T, von Keyserlingk M A G, Weary D M
Animal Welfare Program, Faculty of Land and Food Systems, University of British Columbia 2357 Main Mall, Vancouver, B.C., V6T 1Z4, Canada.
Animal Welfare Program, Faculty of Land and Food Systems, University of British Columbia 2357 Main Mall, Vancouver, B.C., V6T 1Z4, Canada.
Vet J. 2019 May;247:57-60. doi: 10.1016/j.tvjl.2019.02.012. Epub 2019 Mar 2.
Intramuscular (IM) injections may be more aversive than subcutaneous (SC) and intra-nasal (IN) routes. Xylazine is commonly used as a sedative for cattle, but little is known about efficacy via these routes. The first aim of this study was to compare efficacy using these different routes of administration. The second aim was to determine whether a simple behavioural assessment was associated with physiological responses. Using a within-subject design, the effects of xylazine (0.2mg/kg) were assessed in 12 Holstein calves (6.2±2.8days old) administered via IM, SC, IN drip tube (IN) and IN spray (INs). Sedation was assessed on a scale based on recumbency and eyeball rotation. Heart rate (HR), respiratory rate (RR) and rectal temperature (RT) were recorded for 2h after treatment. Intramuscular and SC routes produced an equivalent mean±standard deviation (SD) onset of sedation (IM: 4.8±2.0min vs. SC: 6.8±2.2min) and duration of sedation (IM: 60.3±25.5min vs. SC: 61.9±23.3min). IN treatments produced less consistent and longer onset times (IN: 33.0±26.9min, and INs: 31.0±15.1min) and a shorter duration of sedation (IN: 42.0±31.5min, and INs: 26.7±21.8min). Behaviour scores were moderately correlated with changes in HR (r=-0.52; CI -0.60, -0.43) and changes in RR (r=-0.42; CI -0.51, -0.32), but not with changes in RT (r=-0.09, CI -0.20, 0.02). We conclude that SC is a viable alternative to the more aversive IM route, and that a simple clinical scale can be useful for assessing xylazine sedation.
肌肉注射（IM）可能比皮下注射（SC）和鼻内注射（IN）更让动物反感。赛拉嗪通常用作牛的镇静剂，但对于通过这些途径给药的效果了解甚少。本研究的首要目的是比较使用这些不同给药途径的效果。第二个目的是确定简单的行为评估是否与生理反应相关。采用受试者内设计，对12头荷斯坦犊牛（6.2±2.8日龄）经肌肉注射、皮下注射、鼻内滴注管给药（IN）和鼻内喷雾给药（INs）后给予赛拉嗪（0.2mg/kg）的效果进行评估。根据卧姿和眼球转动情况对镇静效果进行评分。治疗后2小时记录心率（HR）、呼吸频率（RR）和直肠温度（RT）。肌肉注射和皮下注射产生的镇静起效时间（平均±标准差）相当（肌肉注射：4.8±2.0分钟，皮下注射：6.8±2.2分钟），镇静持续时间也相当（肌肉注射：60.3±25.5分钟，皮下注射：61.9±23.3分钟）。鼻内给药治疗产生的起效时间更不一致且更长（鼻内滴注管给药：33.0±26.9分钟，鼻内喷雾给药：31.0±15.1分钟），镇静持续时间更短（鼻内滴注管给药：42.0±31.5分钟，鼻内喷雾给药：26.7±21.8分钟）。行为评分与心率变化（r=-0.52；可信区间 -0.60，-0.43）和呼吸频率变化（r=-0.42；可信区间 -0.51，-0.32）呈中度相关，但与直肠温度变化不相关（r=-0.09，可信区间 -0.20，0.02）。我们得出结论，皮下注射是更让动物反感的肌肉注射途径的可行替代方法，并且简单的临床评分可用于评估赛拉嗪的镇静效果。
