being said, although the main distinction between the two is size, size is not the only determining factor. There are some horses smaller than a typical pony size that are not ponies but horses. For instance, breeds such as the Falabella horse, which stand no taller than 7.5 hands, are considered very small horses, not ponies. Further, Caspian horses almost always are under 12 hands, yet aren’t considered ponies.