Kaze no Sylphid

Sylphid is a horse born on a small horse ranch. Even though he is named for a fairie wind he must overcome the handicap of having been born with tendinitis of the leg, and the loss of his mother in his birth. Hayao the young boy who loves horses is determined to see Silpheed grow up healthy and become a top racer like his mother once was. However, the odds are stacked against the orphaned foal and the young boy.

(Source: MangaFox)