Hmmm....this could be a hard one. Well, is a paragraph something? haha
To any one horse; I would choose Chester and say, I love you. Because in those words, mean so much. It's not just, I love you, it's; I love being around you, doing things with you, I'm glad your mine, I care for you, ect.
I would also tell him, that all I want is to be his friend, companion and to be a team together.
I if were to say something to all the horses in the world, now that would be different. I would probably say, "We're not trying to hurt you, we're trying to communicate with you, take care of you and be your friends." I don't know if that would be weird or not, but other then that I don't know what I'd say. Or is that just an obvious one that everyone would say?