I recently went on a Farm call with my trainer (also a vet) to euthanise a horse. I had to hold the horse while she injected her. The horse was very skinny and couldn't get up so she had to put it down. This made me so sad and as I looked at the other horses, though they weren't gross, they were slender (except one really fat pony) and there was no shelter.
A long time ago, I made this video as a kind of PSA.. I'm not sure if I've posted this before or not, but here it is anyway: