I gave in to my dark desires and joined a SIM Horse game. Yes, they exist.
Believe it or not http://www.equine-ranch.com is one of the most realistic simulations of horse breeding, training and showing there are. It has a huge collection of races and a great variety of colors. Did you always wanted to have your own ranch and make a line of show winning horses but you don’t have the money? Then this might be the right game for you.
Beware! There’s lots of reading and some of the game mechanics are expected to be discovered on your own.