During training or racing, horses may reach and sustain exercise intensities capable of overwhelming the musculoskeletal system's response capacity, which can result in severe and sometimes fatal musculoskeletal injuries. These have been reported as the main reason for racing wastage.1-5 Catastrophic musculoskeletal injuries requiring euthanasia may fuel public antiracing sentiments, result in decreased public support for racing, and constitute an undesirable outcome for racehorses. Although racing injuries have been described in other racing jurisdictions, 6-9 there are many variables pertaining to their occurrence that make it difficult to extrapolate information among geographic regions. Comparisons among studies are hampered by a lack of consensus as to what constitutes a specific risk factor for a specific lesion, differences in study methods, and lack of uniformity regarding description of injuries and putative risk factors. Because there are characteristics of CMIs that could be affected by local conditions, extrapolation of scientific data pertaining to other racing jurisdictions may result in inappropriate conclusions. Therefore, it would seem appropriate to study CMIs in each racing jurisdiction. Local studies have the advantage of being relevant to the specific jurisdiction, racing conditions, and training practices.
Investigation of racehorse fatalities increases the industry's accountability for the use of animals and allows for the implementation of strategies to reduce their incidence.10 In other North American racing jurisdictions, the overall prevalence of fatal musculoskeletal injuries in Thoroughbred racing ranges from 1.2 to 1.7/1,000 starts,6-8 and in another study,11 0.44% of horses required assistance to move off the racetrack. Few studies have investigated CMIs that occurred during training. However, prevalence for all training injuries resulting in lameness has been reported as 45%.6 Accurate acquisition and evaluation of these data are difficult because several factors cannot be controlled during training, which makes the obtained information potentially inaccurate and incomplete. Therefore, objectives of the study reported here were to determine characteristics, incidence, and possible associations with selected demographic characteristics of CMIs in Thoroughbred racehorses in Ontario, Canada.
Catastrophic musculoskeletal injury
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