How do horses show their dominance?

good question! first of all, if you are not very experianced with horses, learn more before you start training them. You should never under any circumstances, let the horse do what you don't want it to. Do not be afraid to "hurt the horses feelings" or hurt the horse itself. make sure you do lots of training and reward it when it does something good. discepline is the key to dominating a horse.

good luck! :)