Survival Analysis of Training Methodologies and Other Risk Factors for Musculoskeletal Injury in 2-Year-Old Thoroughbred Racehorses in Queensland, Australia.
Authors: Crawford Kylie L, Finnane Anna, Greer Ristan M, Barnes Tamsin S, Phillips Clive J C, Woldeyohannes Solomon M, Bishop Emma L, Perkins Nigel R, Ahern Benjamin J
Journal: Frontiers in veterinary science
Summary
# Editorial Summary Musculoskeletal injuries in 2-year-old Thoroughbreds remain a significant welfare and economic concern, yet training recommendations for this age group lack robust evidence. This prospective Queensland-based study tracked 535 young horses across 26 trainers over 56 weeks, collecting weekly exercise data across 1,258 training preparations to identify injury risk factors specific to this developmental stage. Counter to conventional wisdom about protecting young horses from fast work, increased high-speed exercise exposure substantially reduced overall injury risk (hazard ratio 0.89), whilst later commencement of training increased injury hazard by 13% per additional month of age—findings that directly challenge current industry practice. Dorsal metacarpal disease, the most common injury in this cohort, showed similar protective effects with cumulative distance and gallop days, but additionally benefited from non-ridden training modalities (9% risk reduction) and showed marked sex dimorphism, with colts nearly 2.6 times more likely to be affected than fillies. Practitioners should consider earlier, progressive introduction to race training with strategic incorporation of high-speed work and varied training modalities, whilst paying particular attention to young colts and first-preparation horses, where injury risk peaks.
Read the full abstract on PubMed
Practical Takeaways
- •Start training 2-year-olds earlier rather than later—delaying training actually increases injury risk; commencing training should be based on individual readiness rather than arbitrary age cutoffs
- •Incorporate high-speed work and multiple training preparations strategically into conditioning programs, as both reduce injury hazard in young racehorses
- •Use non-ridden training modalities (lunging, swimming, treadmill) as part of preparation, particularly for colts and horses showing dorsal metacarpal disease risk factors
- •Monitor first-time training horses intensively, as initial training preparations carry highest injury risk—adequate rest between preparations is protective
Key Findings
- •Earlier training commencement age reduced injury hazard (HR 1.13 per year delay, p<0.001), contrary to common practice of delaying training
- •Increased high-speed exercise exposure was protective against musculoskeletal injury (HR 0.89, p<0.001) and dorsal metacarpal disease
- •Multiple training preparations in a season reduced injury hazard substantially (HR 0.58 overall, HR 0.43 for dorsal metacarpal disease, p<0.001)
- •Male 2-year-olds had 2.58-fold higher risk of dorsal metacarpal disease than females (p=0.02)