Horse

Horses are pets which will be featured in The Sims 3: Pets. While custom content creators have made horses for The Sims and The Sims 2, this is the first time they have been included in an expansion pack.

The Sims 3: Pets
Horses will appear with traits. Sims will be able to ride horses to their destination, and horses will be able to rear up or buck Sims out of their grip. Sims can even die from falling off too hard. Also, judging by the official announcement trailer, horses can befriend other animals such as cats and dogs. It also appears that horses will be able to be entered in competitions. Also, there will be more than 5 different breeds of Horses.

It may be true that you are able to train your own horse by breaking it in. If this is true, it may mean that there shall be horses in the wild as well as in stables and sims homes. This has been mentioned by many of the games testers.

It appears that Sims will be able to ride English, since the pictures of horses indicate an English saddle. This likely means the competitions Sims will be able to enter English shows, such as Dressage or Show Jumping. Also, in one trailer, a sim is riding a horse named Clover which looks like she has no saddle. This may mean you are able to ride Bareback aswell. It is unknown if you can ride Western though.