Why do horses have a stone on one of their legs?

Horses don't have a stone on their legs! That's a funny idea. They do have a special bone called the "cannon bone".

* Cannon bone: This is a large, thick bone that makes up the lower part of their leg, right above the hoof. It's very strong to support the horse's weight.

Maybe you're thinking about the "chestnut", which is a hard, dark growth found on the inside of the horse's legs just below the knee or hock. It's not a stone, but a thickened area of skin. No one knows exactly what its purpose is!

Let me know if you have any more questions about horses. 😄