You know what is funny? Piebald, referring to horses, means strictly a horse that is patched, black and white. BPs should have technically been called Skewbald, IMO. This is a horse with white, and any other color patches (brown.. BP-ish..) if they were naming it after horses..
I am not sure about the rest of the animal world. And if, say, dogs that are brown and white, are Pieds in their registries. But I know this about horses!