Strand E, Fjordbakk C T, Holcombe S J, Risberg A, Chalmers H J
Equine Teaching Hospital, Norwegian School of Veterinary Science, P.O. Box 8146 Dep., N-0033 Oslo, Norway.
Equine Vet J. 2009 Jan;41(1):59-64. doi: 10.2746/042516408x330392.
Dynamic laryngeal collapse (DLC) associated with poll flexion is a newly diagnosed upper respiratory tract obstructive disorder that causes poor racing performance.
To determine if Norwegian Coldblooded Trotters (NCTs) affected with DLC associated with poll flexion differ from normal, elite NCTs based on simple airway mechanics measurements.
Five normal elite NCTs and 6 NCTs diagnosed previously with DLC underwent treadmill videoendoscopy while tracheal pressures were measured continuously. Alternating head positions were used such that horses were exercised with free head carriage and induced poll flexion at heart rates >200 beats/min.
Peak inspiratory tracheal pressures were significantly more negative for horses with DLC compared to the elite horses. This difference was only significant during the exercise phases when the poll region was flexed, P = 0.0015. Head position significantly affected peak inspiratory pressure for both elite and affected horses, P < 0.0001.
Induced poll flexion significantly affected peak inspiratory pressure (PIP) in all horses; however, PIPs were significantly more negative in those affected with DLC. Based upon the tracheal pressure measurements recorded in this study, DLC in NCTs is a severe obstructive upper respiratory tract disorder that is induced by poll flexion.
与低头屈曲相关的动态喉塌陷（DLC）是一种新诊断出的上呼吸道阻塞性疾病，会导致赛马成绩不佳。
基于简单的气道力学测量，确定患有与低头屈曲相关的DLC的挪威冷血快步马（NCT）与正常的精英NCT是否存在差异。
对5匹正常的精英NCT和6匹先前诊断为患有DLC的NCT进行跑步机视频内窥镜检查，同时持续测量气管压力。采用交替头部位置的方式，使马匹在头部自由状态下运动，并在心率>200次/分钟时诱导低头屈曲。
与精英马匹相比，患有DLC的马匹吸气末气管压力峰值明显更负。这种差异仅在低头区域屈曲的运动阶段显著，P = 0.0015。头部位置对精英马匹和患病马匹的吸气末峰值压力均有显著影响，P < 0.0001。
诱导低头屈曲对所有马匹的吸气末峰值压力（PIP）均有显著影响；然而，患有DLC的马匹的PIP明显更负。基于本研究记录的气管压力测量结果，NCT中的DLC是一种由低头屈曲诱发的严重阻塞性上呼吸道疾病。
