Fifteen risk factors associated with sudden death in Thoroughbred racehorses in North America (2009-2021).

The research focuses on identifying risk factors associated with race-associated sudden deaths in Thoroughbred horses in North America, specifically, the US and Canada, from 2009 to 2021.

Research Context

• The data for the research was obtained from over four million race starts by almost 285,000 Thoroughbred horses at 144 racecourses across the US and Canada, as recorded in the Equine Injury Database.
• Fatalities that occurred due to sudden death within three days of a race were the main subjects of the study. However, deaths resulting from catastrophic musculoskeletal injuries were excluded.

Research Methodology

• The researchers considered 49 potential risk factors and analysed these using both univariable and multivariable logistic regression methodologies.
• These potential risk factors covered a broad range of parameters such as the horse’s age and sex, the season of the race, the purse for the race, and the race distance.
• Furthermore, factors concerning the horse’s recent history of injury and lay-ups were also considered for the analysis.

Research Findings

• During the course of the study, 536 race starts resulted in sudden death equating to an incidence rate of 0.13 per 1,000 starts.
• The study identified 15 risk factors that were significantly associated with sudden death. These included the horse’s age, sex, previous injury, and whether they were racing while on furosemide medication.
• The study found that horses racing while on furosemide medication had a 62% increased odds of sudden death, which prompts further investigations into the biological processes that might contribute to this result.
• Furthermore, the established link between previous injury and sudden death indicates that underlying health conditions could be a contributing factor in some cases.