Your reliable sources are wrong. There is such a thing as humane horse slaughter, and it no doubt isn’t being used in Mexico, like it was in this country before the do-gooders “fixed things.”
I trust my sources and consider it a gross betrayal of a beloved companion animal to subject it to such terror and inhumane death.
I have nothing against the humane euthanasia of even a healthy horse if the alternative is for it to be abandonded to a slow death. But I will never advocate for horses being sent to slaughter.
It is a shameful fate for an animal that has served us so well.