Meta-analysis of risk factors for racehorse catastrophic musculoskeletal injury in flat racing

•A systematic search of peer-reviewed studies on racehorse injury or fatality from 1990 to 2017 was performed.•The pooled incidence of catastrophic musculoskeletal injury was 1.17 (95% confidence interval 0.90, 1.44) per 1000 starts.•Almost 300 potential risk factors have been investigated for associations with catastrophic musculoskeletal injury.•Horse-level risk factors included horse age, sex, exercise and veterinary history, and indicators of the horse’s quality.•Race-level factors included track type and conditions, race distance, and field size.