Physick-Sheard Peter, Avison Amanda, Sears William
Department of Population Medicine, University of Guelph, Guelph, ON N1G 2W1, Canada.
DVM Program, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada.
Animals (Basel). 2021 Oct 13;11(10):2950. doi: 10.3390/ani11102950.
Ontario's Alcohol and Gaming Commission records equine racing fatalities through its Equine Health Program. The present study examined all Thoroughbred fatalities from 2003 to 2015, inclusive, to identify associations. Official records and details of fatalities were combined in multivariable logistic regression modelling of 236,386 race work-events (433 fatalities), and 459,013 workout work-events (252 fatalities). Fatality rates were 2.94/1000 race starts (all fatalities) and 1.96/1000 (breakdowns only) with an overall rate of 2.61% or 26.1 fatalities/1000 horses. Comparison with published reports reveals rates to be high. Musculoskeletal injury was the predominant complaint and there was a high incidence of horses dying suddenly. Liability was high for young horses early in the season with a differential according to sex and whether a male horse was gelded. Horses undertaking repeated workouts had a higher liability and liability was higher in workouts for horses switching from dirt/synthetic to turf racing and for young horses in sprints. Race distance was not significant but high fatality rates in some large field, distance races combined with effects of age and workload identified groups at particular risk. As field size increased, fatality liability increased for early-finishing horses. Findings suggest jockey strategy could be an important factor influencing fatalities. Probability of fatality declined over the study period. Findings indicate that rapid accumulation of workload in animals early in their preparation is likely to be damaging. Fatality fell toward the end of a season and for horses with a long career history of successful performance; however, horses not exhibiting this robustness and staying power represent the population of greatest concern. Associations may be characterised as representing sources of stress, current or cumulative, and identifying at-risk animals on this basis may be as productive as targeting specific, discrete mechanisms suspected to contribute to individual fatalities.
安大略省酒精和博彩委员会通过其马匹健康计划记录赛马死亡情况。本研究调查了2003年至2015年（含）期间所有纯种马死亡情况，以确定相关关联因素。官方记录和死亡详情被纳入对236,386场比赛赛事（433例死亡）和459,013场训练赛事（252例死亡）的多变量逻辑回归模型中。死亡率为每1000场比赛起跑2.94例（所有死亡情况）和每1000场起跑1.96例（仅骨折情况），总体死亡率为2.61%，即每1000匹马中有26.1例死亡。与已发表报告的比较显示该死亡率较高。肌肉骨骼损伤是主要问题，马匹突然死亡的发生率也很高。赛季初期幼马的死亡风险较高，且存在性别差异，雄性马去势与否也有不同。进行重复训练的马匹死亡风险更高，从泥地/合成跑道转换到草地跑道的马匹以及幼马短跑训练时死亡风险也更高。比赛距离并非显著因素，但一些大型赛场、长距离比赛中的高死亡率，再加上年龄和工作量的影响，确定了特定的高风险群体。随着赛场规模增大，早结束比赛的马匹死亡风险增加。研究结果表明骑师策略可能是影响死亡情况的一个重要因素。在研究期间死亡概率下降。研究结果表明，动物在准备初期工作量的快速积累可能具有损害性。赛季末以及有长期成功比赛历史的马匹死亡率下降；然而，未表现出这种强健性和耐力的马匹是最值得关注的群体。相关关联因素可被描述为代表当前或累积的压力源，在此基础上识别高风险动物可能与针对怀疑导致个体死亡的特定、离散机制一样有效。
