You are giving human emotions to an animal that cannot possibly feel the same things as a human can. To us as humans, we see that the horse is giving his all for a human and the only way we can identify with it, or describe it, is to match it to an emotion that we can feel. Horses do not feel things the same way as we do. Their brains are not as developed as a human's brain.
So that is like saying saying that if two horses are together for their entire life and then one passes they wont morn???? I completely disagree. Or saying that a horse is 25 years old and had an extremely strong bond with that owner and the horse is sold or the owner passes...they don't morn??? They don't miss that??? Yes, I have to say I completely disagree with that concept. That's just like a dog loosing another dog that was a close companion they morn, they greive, just like people do. I do believe that animals feel and that they do have hearts just as we humans do.