I know almost nothing about the sport other than it involves horses, foxes, and the killing of foxes. While I find the fox to be a beautiful animal, I see no problem in hunting them. My only condition on this, however, is that the meat of the fox, as well as the skin, organs, bones, etc, go on to be used for something. I also do not like mounting dead animals on a wall. I find it disrespectful to the dead. If you want to remember it, take a picture and hang that instead. Anyway, I"m getting off my soap box now.
But in a nutshell, I have no problem with it. As long as it is done respectfully, and does not endanger the population or the surrounding ecosystem.