I've got a horse that I'm trying to keep alive for a particular achievement. Unfortunately, this horse seems a bit suicidal. Several times he's stepped out in front of my shot during a gunfight and taken a rifle round to the head. In other instances, he blunders into the wilderness when I stop to hunt, and ends up cougar food. Still other times he's gotten spooked and jumped into a river and died.
When I'm going to be doing something potentially dangerous to my horse (turning the game on, for example), I'd like to be able to tell him to go away. I can always call him back with my magic-pocket-dimension-opening whistle if I need to, but there are times when I need to go far afield and walking just isn't going to cut it. I could bring a "disposable horse" but this achievement is awfully picky and I'd rather stick with just one horse until I get it.
Is there any way to dismiss my horse so that he despawns and is no longer at risk?