This is evidence that even the eeriest of topics can be documented into a balanced piece which tries to give a voice to all parties involved in the subject matter. I'm not condoning this behavior at all, but fortunately it was made with such quality, above average quality and care, that it deserves very high marks.
It's very well made documentary about an even more disturbing lifestyle... at least for those of us who are not into zoophilia, of course. Nevertheless, it's intended to cause an empathic reaction on the audience, although I can't say many people will feel any sympathy.
I know it's difficult, but place your prejudice about sexual behavior, sit back, watch and listen... that's all it takes and come back with a very uncomfortable topic of conversation at your next friendly gathering.