Investigation of factors associated with the probability of racehorses being pulled up in steeplechase races at Cheltenham racetrack

Abstract

Limited research has been conducted to investigate the risk factors associated with horses being pulled up in steeplechase races. The aim of this study was to identify risk factors associated with pulled up horses in steeplechase races at Cheltenham racecourse and utilise these to propose preventative strategies to reduce prospective risks of racehorses being pulled up in steeplechase races. Horse and racetrack factors that could be associated with an increased chance of horses being pulled up, extrapolated from previous research into racehorse falls and clinical injury, were identified and collated via the Racingpost website for all steeplechases (n=1,032) at Cheltenham for a 21 year period (January 1990 - December 2010). A logistic regression was used to model the probability of existence of pulled up horses in a given race. A negative binomial regression was used to model the number of pulled up horses in a given race. Increasing numbers of runners (P<0.001) starting a race and races of longer distances (P<0.001) resulted in more pulled up horses within the race. In contrast, faster race speeds (P<0.01) were associated with the presence of less pulled up horses in a race. Each additional m/s in the speed of the horses running the race in race results in a decreased probability of 38.1% that the race will contain pulled up horses. The influence of other horses within steeplechase races at Cheltenham appears to effect speed within racing and can exert a positive or negative influence on how many horses are pulled up in a race. It is suggested that additional co-variant factors such as going and distance can also impact upon speed, and that it is the interaction of these variables that produce equine fatigue resulting in pulled up horses. The predictive models devised have the potential to be employed to assess risk of horses being pulled up for other racetracks.