Equine Section, Norwegian School of Veterinary Science, Oslo, Norway.
Equine Vet J. 2012 Sep;44(5):518-23. doi: 10.1111/j.2042-3306.2011.00517.x. Epub 2011 Dec 12.
Two genetically and phenotypically distinct horse breeds are used for harness racing in Scandinavia: the Standardbred (SB) and Coldblooded Trotter. These racehorses have identical environmental, management and racing conditions. Therefore, this study was undertaken to identify and compare the relative prevalence of upper respiratory tract (URT) obstructive disorders in these 2 breeds.
To determine whether these 2 phenotypically different breeds of harness racehorses have different predispositions for URT disorders.
Retrospective study of 88 Norwegian Coldblooded Trotters (NCT) and 97 SBs referred to this hospital for URT evaluation between 1998 and 2006. Case records of all horses diagnosed with an URT disorder during resting endoscopy, and all horses undergoing high-speed treadmill videoendoscopy (HSTV) with one or more periods of induced poll flexion were evaluated. The relative prevalence of URT disorders between the 2 breeds was analysed using a Fisher's exact test.
There was a significant (P<0.05) breed predisposition regarding 6 URT disorders. Bilateral dynamic laryngeal collapse associated with poll flexion and flaccid epiglottis was significantly more frequent in the NCT. Alar fold collapse and nasopharyngeal collapse were significantly more frequent in SBs. Epiglottic entrapment and nasal flutter were only diagnosed in the SBs. Dynamic disorders were more common than resting disorders in both breeds.
URT obstructive disorders (dynamic laryngeal collapse associated with poll flexion, flaccid epiglottis, pharyngeal collapse, alar fold collapse, nasal flutter and epiglottic entrapment) are breed related, indicating an anatomic or functional cause. Periods of induced poll flexion during HSTV was essential to declare harness racehorses free of URT disorders.
Further anatomic or physiological studies comparing these breeds could potentially provide insight into the pathogenesis of certain URT obstructive disorders. Induced poll flexion should be included in routine HSTV examinations of all harness racehorses.
在斯堪的纳维亚地区，两种在基因和表型上都截然不同的马种被用于轻驾车赛：标准马（SB）和冷血快步马。这些赛马具有相同的环境、管理和比赛条件。因此，进行这项研究是为了确定并比较这两个品种的上呼吸道（URT）阻塞性疾病的相对患病率。
确定这两个表型不同的轻驾车赛马品种是否对上呼吸道疾病有不同的易感性。
对 1998 年至 2006 年间因 URT 评估而转诊至该医院的 88 匹挪威冷血快步马（NCT）和 97 匹 SB 进行回顾性研究。对所有在休息内镜检查中被诊断为 URT 疾病的马匹的病例记录，以及所有在高速跑步机视频内镜检查（HSTV）中进行一次或多次诱发策动屈曲的马匹的病例记录进行评估。使用 Fisher 确切检验分析两种品种之间 URT 疾病的相对患病率。
在 6 种 URT 疾病中，存在着显著的（P<0.05）品种易感性。双侧动态喉塌陷伴策动屈曲和软腭是 NCT 中更常见的疾病。SB 中更常见的是鼻甲折叠塌陷和鼻咽塌陷。软腭嵌塞和鼻瓣性呼吸困难仅在 SB 中被诊断出。在两种品种中，动态疾病比休息疾病更为常见。
URT 阻塞性疾病（与策动屈曲相关的动态喉塌陷、软腭、咽塌陷、鼻甲折叠塌陷、鼻瓣性呼吸困难和软腭嵌塞）与品种有关，表明存在解剖或功能原因。在 HSTV 中进行诱发策动屈曲的时期对于宣布轻驾车马无 URT 疾病是必要的。
进一步比较这些品种的解剖学或生理学研究可能会深入了解某些 URT 阻塞性疾病的发病机制。在所有轻驾车马的常规 HSTV 检查中应包括策动屈曲。
