A zillion years ago when I was a teenager, my friend had a horse and she had to move him to a different pasture (more affordable boarding). He got spooked during a windstorm and got out of the barn. Unfortunately they had 'snow fencing' (low fence made out of cheap strips of wood often used to block blowing snow). Prince couldn't see it and got fouled in it and by the time she found him the next morning he was in bad shape.
We tried everything (and me a total horse novice - I'm hugely allergic to them, but I liked him and he liked me). He was trying to lie down b/c he'd given up and we two girls were adamant we weren't going to let him give up.
We manhandled a big huge belt off a piece of farm machinery and rigged a block and tackle to a beam in the ceiling to help him stand (we really didn't understand he'd given up -- we thought he was too weak to stand).
Bless his heart he tried SO hard for us girls. But the vet had to put him down. We were just a couple of very ignorant but well-meaning girls and it always made me mad that her parents had made her move him to this other place (and the monetary difference was small).
I've always loved horses as long as I can keep it to a face-to-face thing LOL. I'm willing to make friends and then go sneeze myself into oblivion and itch to death later ...