Horses chased to death in Texas. August 27, 2012.

I was going to ask the same thing. I see no connection whatsoever. I have that game (Red Dead Redemption) and there is no hint of chasing horses until they drop. In fact, if you even harm or 'assault' a horse, the game ends (unless you are in cheat mode or it's an enemy's horse during gameplay.) It does not encourage animal abuse.