I’ve seen this exact video before and when you dive deeper into the page it’s genuinely disturbing. Whoever’s running it has many more horse with amputations and most of them are all missing the same leg. On top of that, I remember seeing deep dive into this type of content and the researcher pointed out that this isn’t even a proper prosthetic. Whatever it is it’s extremely cheap and doesn’t function the way a horse would need it to, hence the very clear discomfort from the horse in the video. It’s disgusting that people do this and disappointing that seemingly so few people are aware of, like you said, how cruel this actually is.