Gait and speed as exercise components of risk factors associated with onset of fatigue injury of the third metacarpal bone in 2-year-old Thoroughbred racehorses.

The research article investigates the relationship between different components of training programs for 2-year old Thoroughbred racehorses, such as the horse’s gait and speed, and their propensity to sustain an injury known as bucked shins. Essentially, the study shows that tweaking a horse’s training routine—incorporating more short-distance breezing and reducing long-distance galloping—can decrease the likelihood of such injuries.

Methods

• The study was conducted on 226 two-year-old Thoroughbred racehorses. The researchers gathered daily training data and health reports from 5 different commercial stables. The collected data regarded the distances covered by the horses at different paces: jogged (approximately 5 m/s), galloped (approximately 11 m/s), and breezed (approximately 15 to 16 m/s).
• A follow-up was done until the first occurrence of bucked shins in any of the horses. Analysis was carried out using cross-tabulation, graphic, and survival techniques.

Results

• Out of the 226 racehorses, 56 developed bucked shins, 9 completed the study period without developing bucked shins, while 161 were lost to follow-up.
• Different training strategies were employed by the stables, leading to significantly different survival profiles among them. Survival, in this context, refers to the absence of bucked shins during the observation year.
• The average mile allocation to variable exercise types was outlined. The amount of exercise attributed to breezing was found significantly reducing the survival rate, meaning breezing led to a higher incidence of bucked shins. On the contrary, exercise attributed to galloping significantly increased survival, indicating a smaller likelihood of acquiring bucked shins. The amount of jogging did not seem to significantly influence the horses’ susceptibility to the injury.

Conclusions

• The study concluded that the different speeds and gaits in the horse’s exercise regimen influence the frequency of bucked shins. It suggests that trainers mitigate the risk of bucked shins by making more room in their training schedules for short-distance breezing and less for long-distance galloping.