Yes, animals should be used in sports and entertainment, because they can be kept safe. If safeguards are put in place, the animals can be safe, and can even be taken care of better than they would be if they were not involved in sports or entertainment. There should be a government body to oversee the animals and make sure they are safe.
I believe that humans are the dominate species on this planet. I believe that we should be able to use any other species to our entertainment as long as it is not harmful to the animal. For example I believe dog races and horse racing is ok but dog and cock fights are not.