What is piggy eye on a horse?

"Piggy eye" isn't a recognized term in horse anatomy or health. It's likely a slang term or mispronunciation.

To better understand what you might be referring to, could you provide more context? For example:

* What are you seeing? Is there a specific appearance or behavior you are observing in the horse's eye?

* Where did you hear the term? Was it from a friend, a book, or online?

Knowing more will help me provide a helpful answer.