Ive never found one that would be pony sized if that's what you mean. Don't think they shoe them. Your shoe is just missing the bottom right side. It would have came down giving it the "U" shape with the bump at the bottom just like the left side has. Looks like about the smallest size I've found if it were hole.
It's an oxen shoe. I found four of them this past Autumn at an old cellar hole. Oxen are like cattle. They need two shoes per foot, because they are cloven-hoofed, I believe is the correct term.