Horses used in the Rangeland Derby chuckwagon races at the 2011 Calgary Stampede in Alberta, Canada, will receive veterinary inspections upon arrival to the event and prior to competition under new rules announced by Stampede management on Feb. 23.

The annual Calgary Stampede features rodeo-style competitions and livestock exhibitions. The Stampede's GMC Rangeland Derby chuckwagon race pits four teams of horse-drawn wagons against each other in a series of elimination races over several days. Traditionally, each team consists of four wagon horses and four horses carrying outriders.

Last year, a total of six horses died in separate Stampede rodeo events. A Quarter Horse suffered an apparent cardiac episode and died during a team cattle-penning event, and a bucking horse was euthanized after breaking his back when he continued to buck after his rider came off in the saddle bronc riding event. Additionally, four Thoroughbreds died in connection with the chuckwagon races. Of those, one died after suffering an apparent cardiac episode during a routine training session, and another died as a result of an abdominal rupture. One horse was euthanized after sustaining a catastrophic injury to his right front leg during a chuckwagon race, and an outrider horse was euthanized after breaking his shoulder during a race.

Stampede spokesman Doug Fraser said that under the new rules, all horses participating in the chuckwagon races will receive veterinary inspections upon arrival to the event. Thereafter, horses will undergo veterinary inspections before each race. Those deemed unfit will be scratched from the event. Horses deemed fit to compete will also undergo post-race veterinary inspections, Fraser said