When I got my horse Andie who is 4. My mom's friend came over to look at her and noticed how her forehead came out a little. She said that meant she was going to be stubborn (Which she is lol) She said something about Andie having a loose bottom lip but she couldn't remember what it mean. I'll try to post a picture if I can.
I'm just curious because she does always have a lose or relaxed bottom lip that kinda droops open a little. She's not sick or hurt-it's just the way her lip is lol
Not sure if it means anything, curious to know if it does. My sister had a big grulla mare, Misty when we were kids that had the floppiest bottom lip ever. We liked to play with it kinda like when little kids do to their lips to make a motorboat sound...she had the patience of a saint :)
Usually it's just a character trait of the horse--all horses, when totally relaxed and sleeping, will flop their lower lips like that. But it can be a sign of neurological deficiencies....not that I would necessarily worry, just keep an eye on it if it really is present all of the time.