Judges decided to suspend Cooper following Wednesday's calf roping event, also called tie-down roping. Cooper struck his horse with his rope while pursuing a calf, which he then failed to lasso.
Shawn Wiese, Cooper's agent, defended the calf roper's actions on Friday.
"Tuf's horse was late coming out of the box. Just like a barrel racer encourages her horse home to the finish line or a chuck racer encourages their horses to the finish line, Tuf had to get his horse going to catch up to the calf," he said in a statement.
"Tuf would never harm any animal let alone his own horses. Tuf treats his horses like royalty and their health and well-being are top priority … All rodeo athletes have respect for the animals involved in the sport and would never intentionally harm them."
A 1st for Calgary Stampede
Calgary Stampede spokeswoman Kristina Barnes said it's believed to be the first time a competitor has been disqualified from the rodeo for "mistreatment of livestock."
"The six judges, along with Calgary Stampede officials, unanimously made the decision to disqualify Cooper after seeing him repeatedly and aggressively using his rope on his horse during the run," she said in an email on Thursday.
"The Calgary Stampede takes its animal care protocols very seriously and enforces them among anyone who handles animals on Stampede Park, whether its staff, volunteers or competitors."
Champion calf roper
Cooper is a champion tie-down roper who had earned more than $1 million US during his rodeo career by the time he turned 23, according to the Calgary Stampede's website. His father is Roy (Super Looper) Cooper, a world rodeo champion.
Also coming to the rodeo star's defence on Friday was Cecil Rhodes, the owner of a second horse that Cooper rides.
Rhodes posted a long letter of support on Cooper's Facebook fan page, saying Cooper has never abused Topaz.
"He has a very tender heart and love for all things, especially animals. Indeed, Tuf is a living role model, in the truest sense of the concept, to any young person, male or female. Tuf truly is an amazing young man and, at 70 years old, I am proud, very proud, to consider him a friend and he can ride, show, and keep any of our horses, anytime!"