Looks very good. I would only suggest, maybe don't have such a harsh transition from the gut to the.... part of the horse just below the gut. if you rounded that a bit more it would look more natural, I think, and she could still have that nice belly. Good job, though, It looks really good.
"So the Doctor Sais I wouldn't have so many nose bleeds if I kept my finger out of there."
~Ralph Wiggum