Horses are far more intelligent than Dogs and Cats. This is totally inhumane.
Are they really more intelligent than dogs? Sure, they have bigger brains and all...personally I think horses are just about as intelligent as cats, whatever intelligence they have is outweighed by their natural skittishness in most cases. I don't have tremendous experience with horses, but I recently spent a modest amount of time with my friends' horses. He's a race trainer. My impression is that they are pretty dumb, nowhere near as good learners as dogs. Yes, they have pretty good instincts; but intelligence? (and...intelligence could be defined several ways) They sure seem overly capable of running into things and hurting themselves.
I am taking them at their word that the herds must be thinned for their own health. It seems that they try to get them long term homes for most of them but these 6 fell through the cracks. Of course these are wild animals and it may have been a last resort. Feral dogs cats, pigs and cattle often times must be destroyed.