Nout-Lomas Y S, Page K M, Kang H G, Aanstoos M E, Greene H M
College of Veterinary and Biomedical Sciences, Colorado State University, Fort Collins, USA.
Equine Research Center, Department of Animal and Veterinary Sciences, California State Polytechnic University Pomona, USA.
Equine Vet J. 2017 May;49(3):334-340. doi: 10.1111/evj.12602. Epub 2016 Jul 23.
There is poor agreement between observers of equine neurological gait abnormalities using the modified Mayhew grading scale.
To stimulate a dose-dependent ataxia in horses through xylazine administration and identify quantifiable relevant gait parameters.
Balanced, randomised, 2-way crossover design.
Eight horses were assessed before and after administration of xylazine (low dose and high dose). Gait analyses performed before and after xylazine administration included: 1) kinematic data collected on an equine high-speed treadmill (flat and 10% decline) and from accelerometers placed on head and sacrum; and 2) kinetic data collected on a force plate.
All horses developed dose-dependent ataxia. Horses developed a dose-dependent increased stride time, stride length, and time of contact (P<0.0001), and a decreased stride frequency (P<0.0002) after administration of xylazine. Although pelvic acceleration increased in the mediolateral direction (P<0.05) in horses walked on the treadmill, this movement decreased when walking over ground after administration of xylazine (P<0.05). Furthermore, centre of pressure and path length indices changed significantly in horses following administration of xylazine (P<0.05).
This study examined one breed of horse (Arabian), all of similar height and weight. Accelerometers were attached to skin, not bone; no correction was made for artefacts from skin displacement. The sedative drug effect is of certain duration, limiting the data collection period.
Administration of xylazine induced a dose-dependent ataxia in horses and resulted in significant changes of gait parameters, pelvic accelerations, and stabilographic variables, some of which changed in a dose-dependent fashion. Some of the altered gait parameters in this model were probably a result of overall slowing down of the stride cycle secondary to the sedative effect. Continued efforts to discover and evaluate quantifiable gait parameters that are susceptible to change following development of clinical neurological disease in horses is warranted.
使用改良的梅休分级量表对马的神经步态异常进行观察时，观察者之间的一致性较差。
通过给予赛拉嗪在马中诱发剂量依赖性共济失调，并确定可量化的相关步态参数。
平衡、随机、双向交叉设计。
对8匹马在给予赛拉嗪（低剂量和高剂量）前后进行评估。赛拉嗪给药前后进行的步态分析包括：1）在马用高速跑步机（平坦和10%下坡）上以及放置在头部和骶骨上的加速度计收集的运动学数据；2）在测力板上收集的动力学数据。
所有马均出现剂量依赖性共济失调。给予赛拉嗪后，马的步幅时间、步幅长度和接触时间呈剂量依赖性增加（P<0.0001），步频降低（P<0.0002）。虽然在跑步机上行走的马的骨盆加速度在内外侧方向增加（P<0.05），但给予赛拉嗪后在地面行走时该运动减少（P<0.05）。此外，给予赛拉嗪后马的压力中心和路径长度指数发生显著变化（P<0.05）。
本研究检查了一个品种的马（阿拉伯马），所有马的身高和体重相似。加速度计附着在皮肤上，而非骨头上；未对皮肤位移产生的伪影进行校正。镇静药物作用具有一定持续时间，限制了数据收集期。
给予赛拉嗪可在马中诱发剂量依赖性共济失调，并导致步态参数、骨盆加速度和稳定图变量发生显著变化，其中一些变化呈剂量依赖性。该模型中一些改变的步态参数可能是镇静作用导致步幅周期整体减慢的结果。有必要继续努力发现和评估在马发生临床神经疾病后易发生变化的可量化步态参数。
