I could not care less about the Kentucky Derby, but that is a very poor comparison. There are clear distinctions to be made between horse racing and dog fighting. There is just about zero similarity between dog fighting and horse racing besides the fact that they both involve animals and sometimes maybe cages (stalls) are involved. The losers don't get brutally torn to shreds by the winner, or at least they haven't in any race I've ever seen.
Perhaps you and everybody else here are a horrible people because we keep carnivorous plants which eat little helpless critters! How many people here have been entertained by that act? I know I have. 
Sure there may be despicable owners that treat their horses poorly, but that's not horse racing's fault. That's the owner's. They are responsible and to blame, not the "sport."
