Annoying chime in and a bit of sad truth from somebody that used to work in a stable.
From the look of the fence, proximity to the street and the fact that it was able to get out at all means these people fucking suck at owning horses.
It also has a top-tier case of rain rot, which means they aren't brushing it and it might not have a proper shelter. Rain rot is painful, triggers aggressiveness, and pretty much everything you see here. From the looks of it, this horse is at the point where it does not want to be touched and is almost impossible to control.
Came here to say what Yogarfield said. It's just a depressing video. Among the questions it raises is what are they recording exactly, and why? Five for human indifference to suffering!
I feel like the horse was running through the forest with the dogs, kicking trees, farting, and just having a great time. Seems like it was a cool fall day and he was feeling very frisky. I bet the dogs and horses are all great friends, play together often, and that the horse never hurts any of the dogs, they get along great, and he was just feeling frisky this day.