It doesn't look to me like the horses are being mistreated in any way. What, all the sudden horses can't swim or walk in water? Bullshit. I am a big fan of animals and animal rights, as is evident in my posts on such subjects, but I don't see a problem here. I don't know, I may be wrong, it's just my opinion guys.
On the other hand, my sympathy does go out to the gent in the middle.