ABSTRACT
Various forms of intensive sport place stress on the musculoskeletal system of the horse, during both racing and training. The musculoskeletal system of the horse has an inherent ability to adapt to the demands of high speed exercise, but exceeding the threshold of adaptive capacity may result in some form of damage. Continuing racing or training may delay the repair process and put the horse at risk of more serious musculoskeletal injury. This study investigated injury in different breeds of horses involved in various types of activity in riding clubs in Tehran. Of the 400 horses that took part in various events during the race season from March 2008 to September 2009, 26 were injured. The most common injury was to the musculoskeletal system of the fore limbs [64%]. The hind limbs suffered 16% of the injuries and the head and neck 4%. From a gender aspect, incident rates were higher in mares [54%] than in stallions [46%]. From a breed point of view, Thoroughbred and Arab horses had higher incident rates [100% and 85% respectively] than a hybrid horse [50%]. Findings of this study also showed the relationship between gender, breed and age of the horses to the injury site, type and outcome, and type of the events