Anomalous Incidence of Fatal Musculoskeletal Injury in North American 2-Year-Old Thoroughbred Racehorses in the Year 2020.
Authors: Bennet Euan D, Parkin Tim D H
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary The COVID-19 pandemic disrupted racing schedules across North America during early 2020, creating an unplanned natural experiment in training schedules for young Thoroughbreds. Bennet and Parkin analysed census-level fatality data from the Equine Injury Database spanning 2009–2022, stratifying fatal musculoskeletal injuries by age cohort to isolate the effect of delayed training onset. A statistically significant spike in fatal injuries occurred specifically among 2-year-olds during 2020, whereas older horses showed no elevated risk that year, and fatality rates normalised when 2020's cohort returned to standard training schedules as 3-year-olds in 2021. This finding suggests that the interruption to early training—rather than permanent changes to physiology—was the critical risk factor, pointing to the vulnerability of immature musculoskeletal systems that are suddenly subjected to racing demands after an unscheduled deconditioning period. For practitioners involved in young horse development, the data reinforce the importance of progressive, consistent training schedules and highlight that gaps in conditioning, particularly during the critical 2-year-old phase, may substantially elevate catastrophic injury risk despite seemingly modest delays to race schedules.
Read the full abstract on PubMed
Practical Takeaways
- •Delayed or interrupted training schedules in young racehorses (2-year-olds) significantly increase fatal musculoskeletal injury risk; gradual resumption of work is critical when training restarts after layoffs
- •Training protocols for young horses should account for deconditioning effects—extended time off increases injury risk more than typical seasonal variation
- •The injury risk from delayed training in 2-year-olds does not appear to have long-term consequences for the same horses when they return to racing at 3 years old
Key Findings
- •Statistically significant increase in musculoskeletal fatalities among 2-year-old Thoroughbreds in 2020 compared to 2009-2019 baseline
- •Delayed training start due to COVID-19 mitigations in early 2020 was associated with increased fatal injury risk in 2-year-olds during that year
- •Fatality incidence returned to pre-2020 levels in 2021-2022 when training schedules normalized
- •Increased risk was specific to 2-year-olds in 2020; 3-year-olds and older horses in 2020 showed no increased risk, and same cohort showed normal risk when aged to 3 years in 2021