Horses aren’t raised for slaughter like cows, nor are they hunted. Most of those that are slaughtered belonged to irresponsible owners and lacking the slaughterhouse many just starved to death.
We have had many horses and we kept them up to their old age and never sent one to slaughter but when it got to where they could no longer eat or lay down and you could see that they were in excruciating pain, we shot them.
The guy I know who has been sending them to slaughter in Mexico just feeds them like you would a normal horse until he gets a truck load.
I’ve seen pleasure horses locked up in a stall most of their lives and it had nothing to do with eating them.
Ask him if they're slaughtered immediately or if they're held in a feed lot.