Have her ovaries checked. I know a pony who was a top show horse, and who subsequently developed some issue or other with her ovaries, and started biting the feet and/or legs of whoever was on her, due to pain. The only other thing I can think of is that she is just plain bored, in which case she might benefit from working somewhere other than an arena – trails, or just gentle hacking around.
- This reply was modified 12 months ago by Joe-Joe. Reason: typo
It is never the horse's fault