Use of validated objective methods of locomotion characteristics and weight distribution for evaluating the efficacy of ketoprofen for alleviating pain in cows with limb pathologies

In veterinary practice pain alleviation plays a part in managing lameness. The aim of this randomized and placebo-controlled clinical study was to evaluate the effect of a single administration of ketoprofen on locomotion characteristics and weight distribution in cattle with foot (located up to and including the fetlock; n = 31) and (proximal to the fetlock; n = 10) pathologies. Cattle were randomly allocated to either the ketoprofen (group K; intravenous 3 mg/kg of body weight; n = 21) or an equivalent volume of isotonic sterile saline solution (group P; n = 20). Two accelerometers (400 Hz; kinematic outcome = stance phase duration; kinetic outcome = foot load and toe-off), a 4-scale weighing platform (weight distribution and SD of the weight) and a subjective locomotion score were measured before (baseline) and after 1 h and 18 h of treatment. All variables were expressed as differences across contralateral limbs, and the measurements at 1 h and 18 h were compared to the baseline. A repeated measures ANOVA was used to determine the differences between groups K and P. A logistic regression model with a binary outcome (0 = no improvement and 1 = improvement of the differences across the contralateral limbs over time) was calculated. Mean (± SD) of locomotion scores at baseline were not significantly different (P = 0.102) in group K (3.10 ± 0.80) as compared to group P (3.48 ± 0.64). Cattle of group K showed significantly lower differences across contralateral limbs at 1 h as compared to group P for the relative stance phase and the weight distribution. Only the treatment (P versus K) remained a significant factor in the model for relative stance phase (odds ratio (OR) = 6.5; 95% CI = 1.38–30.68) and weight distribution (OR = 6.36; 95% CI = 1.30–31.07). The effects of ketoprofen were evident in improving the differences across contralateral limbs—both for stance phase during walking and weight bearing during standing—after 1 h but not after 18 h of administration.在兽医临床实践中，疼痛缓解在跛行管理中占据关键地位。本项随机安慰剂对照临床试验旨在评估单次给药酮洛芬(ketoprofen)对患有蹄部病变（范围至并包括球节；n=31）及球节近端病变（n=10）的牛只运动特征与体重分布的影响。试验牛只被随机分配至酮洛芬组（K组；静脉注射3 mg/kg体重；n=21）或等体积无菌等渗生理盐水组（P组；n=20）。分别于给药前（基线）及给药后1 h、18 h，对所有受试对象开展如下检测：两台采样频率为400 Hz的加速度计（运动学指标为站立相时长；动力学指标为蹄部负重与趾离地动作）、一台四级称重平台（用于测量体重分布及体重标准差(SD)），以及主观跛行评分。所有变量均以对侧肢体间的差值形式表征，并将给药后1 h与18 h的测量值与基线值进行对比。采用重复测量方差分析(repeated measures ANOVA)比较K组与P组间的统计学差异；同时构建以二分类结局为因变量的逻辑回归模型（0代表无改善，1代表随时间推移对侧肢体间差值获得改善）。基线时的跛行评分均值±标准差：K组为3.10±0.80，P组为3.48±0.64，两组间无显著统计学差异（P=0.102）。相较于P组，K组受试牛只在给药后1 h的对侧肢体间相对站立相时长差值与体重分布差值均显著更低。在相对站立相时长（比值比(OR)=6.5；95%置信区间(95% CI)=1.38–30.68）与体重分布（OR=6.36；95% CI=1.30–31.07）的分析模型中，仅治疗分组（P组 vs K组）仍为显著影响因素。酮洛芬的改善效应在给药后1 h即可显现，可有效缩小行走时站立相时长与站立时体重承载的对侧肢体间差值，但该效应在给药后18 h不再显著。