Join Date: Jun 2010
Location: Bucharest, Romania. Eastern Europe
The only situation in which it would be ok to get the horse back would be if his current family is facing financial situations and they would actually be better off without a mouth to feed.
You can carefully try your luck with that: contact the new owners, tell them how happy you are for the horse, tell them how much it means to you, ask for some pictures or eventually if you could see him again.
At the end of the visit (or of the email if you could not meet him) say something like
"If you ever find yourselves in a difficult situation and you can't keep him anymore, I would be more than happy to have him back"
And um, that's about it. If they are having issues with money, space, etc, I am sure they would trust you most to rehome the horse.