Thank you for your wonderful answers- this helps.
So they found the rein- did they say where? I find it hard to believe he would tie up his horse and then do self harm. I can't picture a horse and dog lover doing that, I just can't. I've heard many family, friends, etc say that they are their "babies" "furbabies" etc, especially those that don't have children. If anything, they would make sure that they were well taken care of or all set before doing so.
@Portabella also said something that rings true with me- if he had left out a large bag of dog food and a good amount of water for his dogs, then maybe it's possible, but his horse? I just can't imagine from what I have read about this man, that he would abandon his horse like that.
Much appreciated all the information you have provided in this thread. As I mentioned before, horses are beautiful animals, but unfortunately, I do not know much about them in terms of their care, temperament, etc.