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Equine veterinary journal2025; doi: 10.1111/evj.14503

Novel risk factors associated with fatal musculoskeletal injury in Thoroughbreds in North American racing (2009-2023).

Abstract: The Equine Injury Database (EID) is a census-level record of Thoroughbred racing in North America, currently recording 95.6% of all race starts in 2023, along with partial training and veterinary histories of each horse. Objective: To identify horse-, race- and track-level risk factors associated with race-related fatal musculoskeletal injury (MSI) of Thoroughbred racehorses in North America. Methods: Retrospective cohort study. Methods: The study cohort included all race starts made by horses born after 31 December 2006, at tracks that fully report to the EID and consisted of 3,851,659 race starts made by 250,840 Thoroughbred racehorses (median [IQR] starts per horse 11 [5-22]) at 115 racetracks in the USA and Canada between 2009 and 2023, inclusive. Ninety-seven potential risk factors were investigated using univariable and multivariable logistic regression modelling. Results: Exactly 5733 fatal MSIs were recorded, an incidence of 1.49 fatal MSIs per 1000 starts. Twenty risk factors had statistically significant associations with increased or decreased odds of fatal MSI. Previously unidentified risk factors included claiming race-related variables and void claim rules (VCR). Horses racing as claimers were at increased odds compared with those who were not (odds ratio 1.31, 95% confidence interval 1.19-1.45, p < 0.001 for the lowest claim prices). Starts in races with the strictest VCR were at reduced odds compared with starts in races with no VCR (OR 0.76 [0.67-0.85], p < 0.001). Conclusions: Availability of new data sources increased substantially during the 15-year time period of the study, meaning some new risk factors are limited in scope compared with others. Conclusions: Thoughtful integration of new data sources with race-level data can lead to new insights into risk factors for deleterious outcomes affecting racehorses. Results can inform ongoing efforts to mitigate the risk of fatal MSI, through direct regulatory intervention and through building a risk profile based on individual history and track-level factors.
© 2025 The Author(s). Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.
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Publication Date: 2025-03-25 PubMed ID: 40134143DOI: 10.1111/evj.14503Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research studied the factors related to fatal musculoskeletal injuries (MSI) in thoroughbred racehorses in North America, demonstrating that horses in claiming races, amongst other factors, have increased odds of experiencing MSI.

Research Objective and Methodology

  • The aim of this research was to identify various risk factors that are associated with fatal MSI in Thoroughbred racehorses in North America.
  • For the study, data was collected from the Equine Injury Database (EID), having records of approximately 96% of all race starts in North America for the year 2023.
  • The study utilized a retrospective cohort design, examining the history of horses born after December 31, 2006, and their respective race starts and finishes.
  • A total of 3,851,659 race starts from 250,840 Thoroughbred racehorses across 115 racetracks in the USA and Canada (2009-2023) were included in the study.
  • For the analysis, the researchers investigated 97 potential risk factors using logistic regression modelling.

Research Findings

  • Over the 15-year period, 5733 fatal MSIs were recorded, establishing an incidence rate of 1.49 fatal MSIs per 1000 starts.
  • Among 97 potential risk factors, 20 were found to have statistically significant correlation with the odds of fatal MSI.
  • Newly identified risk factors were related to claiming races and void claim rules (VCR). Claiming races involve horses up for sale at a predetermined price before the race. Void claim rules pertain to withdrawing a claim after a race under certain conditions.
  • Horses in claiming races were found to have 31% increased odds of suffering a fatal MSI, especially those with the lowest claim prices.
  • In contrast, starts in races with the strictest VCR had lowered odds of resulting in a fatal MSI.

Conclusion and Implications

  • The use and integration of new data sources in racing data analysis can provide new insights into the risk factors for adverse outcomes affecting racehorses.
  • The results of this research can guide regulatory action and help develop a risk profile aimed at minimizing the risk of fatal musculoskeletal injuries in racehorses.

Cite This Article

APA
Bennet ED, Parkin TDH. (2025). Novel risk factors associated with fatal musculoskeletal injury in Thoroughbreds in North American racing (2009-2023). Equine Vet J. https://doi.org/10.1111/evj.14503

Publication

Equine veterinary journal
ISSN: 2042-3306
NlmUniqueID: 0173320
Country: United States
Language: English

Researcher Affiliations

Bennet, Euan David
  • School of Biodiversity, One Health, and Veterinary Medicine, University of Glasgow, Glasgow, UK.
Parkin, Tim D H
  • Bristol Veterinary School, University of Bristol, Bristol, UK.

Grant Funding

  • The Jockey Club

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