Exercise-associated sudden death in Thoroughbred racehorses

Frequency of sudden death

Acute collapse and death associated with exercise in apparently healthy Thoroughbred racehorses is a rare occurrence. The overall risk of race-associated sudden death in the UK during 2000–2007 was 0.3/1000 starts. This equates to approximately 25 sudden deaths during racing every year. During this period the risk of sudden death in the different races types was 0.07/1000 starts in turf flat races, 0.09/1000 starts in all-weather track (AWT) flat races, 0.4/1000 starts in National Hunt flat (NH flat) races, 0.5/1000 starts in hurdle races and 1/1000 starts in steeplechases [1].
Proportional mortality of sudden death (proportion of racing fatalities which were classified as sudden death) has also been recorded: 13% (256/1981) in the UK (2000–2009) (British Horseracing Authority), 9% (58/659) in California, USA [2], 19% in Victoria, Australia in flat races [3] and 3.5% in Victoria, Australia in jump races [3].
Although exercise-associated sudden death appears to be a rare event in Thoroughbreds it is a concern for racehorse welfare, jockey safety and the public perception of horseracing. […]