For the sake of fairness and there's always two sides to an issue:
http://insidemovies.ew.com/2012/11/1...on-the-hobbit/
You would expect Jackson and the film-makers to deny responsibility, and it appears none were mistreated or injured during the actual filming. The issue is the "housing" of the animals may have been substandard and dangerous. Of course the company line is "these are disgruntled wranglers, we got rid of over a year ago."
I doubt this will be the last we hear of this story, and so I will continue to reserve judgement on possible mistreatment until more is known.