What bothers me the most about this issue is that people say they can't afford to have their horse put down.
Well, I will say that it costs less to euthanize a horse than it does to feed it for a month or 2.
When I had my last horse put to sleep, it was a 2000 lb horse, and cost me 180$. I rented a digger for 125$ and buried him in the field.
His medication, feed, farrier etc cost more than that for a month of care.
He was my best friend. Would I sell my best friend to a slaughterhouse? Never. His euthanasia was painless and quick. The hardest part was he didn't lay down with the sedation shot and when his heart stopped he crashed to the ground. Seeing him fall like that was hard, but he was dead on his feet literally. It was very fast and he gave NO indication he was hurting at all.
When I am faced with the decision again, I WILL opt to euthanize and bury.
And sorry, everything else- is an excuse.