Hmmm, well the video was strong in feeling, however the ending made no sense, The camera was portraying the life of one individual dog... And at the end you switched it without giving any form of visual conclusion other than "things aren't as the first dog thought."
You showed us what happened to other dogs if they failed through the dogs imagination. Lo and behold he was wrong, cause dog #2 had a home and a different friend. That tells your viewers that there's nothing wrong with racing dogs, they are loved and cared for, and everything else was just in the imagination of the spectators and the dogs.