I’m a big animal person, and I honestly couldn’t find anything truly negative to point out about this movie. It seemed they took care of the dogs used in filming, though that final scene was quite intense. Regardless, it's definitely not for those who are easily upset; there are some uncomfortable moments, but these kinds of things unfortunately happen every day in the world, and no one is doing anything to prevent them. You can’t fault a film for showing reality. I recall another movie recently where someone was attacked by a bear and then put down, but this isn't quite as upsetting for animal lovers. I haven’t seen 'Welcome to the Dollhouse,' but apparently it stems from that one. The filmmaker wrote and directed both, and it’s a comedy drama with several different aspects, all revolving around a single dog—its life story and how its fate changes with each new owner. You might not enjoy every part of the narrative; I personally liked the beginning very much, and many others felt the same way. The second half didn't quite live up to the first. It began promisingly, and if it had concluded similarly, it would have been considered good. However, it lost its focus somewhere in the middle, so now it’s just average, perhaps even a bit below that. Don’t expect this to be like those dog movies you've loved before. The dog is present within the film, but its impact isn't constant. Just consider it as a movie and don't get hung up on how the animal is portrayed. It’s rated R, so it probably isn’t suitable for families. However, it delivers an important message about how dogs are treated in different social classes and by various people and families. For that alone, I think it’s worth seeing, even if it doesn't have broad appeal. So I won’t necessarily recommend it, but it’s not a terrible film like some people claim. My advice is to choose carefully and don't believe everything you hear people complaining about. _5/10_

Source on TMDB