I'll jump to the conclusion that the horse isn't yours.
I do so on the basis of how little regard you show for it's well being.
If someone can afford to feed a horse they can rent a pu for a day I'd think.
Seems to me he was asking an innocent question to make sure he wasn't doing something unsafe, so checking with people more knowledgeable about the subject was smart. You jump down his throat for that? Will you be calling PETA now?