Try howrse.com. I really like it.
yes they do play a game
FunHorseGames.net may be one site that is worth checking out.
Bella Sara is one I know of. But to get more than one horse you have to purchase the cards. They also have unicorns and pegases' along with other mythological horses. <-- na-na-no. Horse isle is...
You know, i really don't know. I will look into it. Ill responder if i find one.*** I have not come across one yet**