Risk factors for equine fractures in Thoroughbred flat racing in North America.

This research identifies risk factors linked to equine fractures during flat horse racing events in North America. By analyzing data from over two million racing events and four million workout starts, the study finds that certain factors increase the likelihood of a horse sustaining a fracture during a race.

Study Objective and Methodology

The primary aim of this research was to identify specific risk factors that contribute to equine fractures during Thoroughbred flat racing in North America. The authors conducted a comprehensive cohort study, considering all starts from racecourses that reported injuries. They used a massive data set spanning six years (2009-2014), which included approximately 2,201,152 racing starts, equivalent to 91% of all official North American racing starts, and nearly 3,990,000 workout starts from 171,523 participating Thoroughbreds.

Key Findings

The study found that the incidence of equine fractures was 2 per 1000 starts. Using a multivariable logistic regression model, the researchers were able to identify several factors significantly associated with an increased likelihood of sustaining a fracture during a race. These factors included:

• A 32% higher chance of fracture when racing on a dirt surface compared to a synthetic one;
• A 35% increased risk for horses that had previously been injured during a race; and
• A 47% greater chance for stallions compared to mares and geldings.

The researchers further used logistic regression models based on data from 2009-2013 to predict the probability of a Thoroughbred sustaining a fracture in 2014. They found that the top 5% of starts predicted to have the highest risk actually showed a fracture prevalence 2.4 times higher than the mean fracture prevalence for 2014.

Implications of the Findings

These results have significant implications for the Thoroughbred racing industry. By identifying horses at a higher risk of sustaining a fracture, race designers and officials can implement preventive measures aimed at reducing these occurrences. Such measures could include better race surface selection, closer monitoring and medical evaluation of previously injured horses, and possible breeding considerations. This could lead to safer racing conditions and improved overall horse welfare in the sport.