I watched the video again. I have seen dogs do preformances like this live but there were smaller dogs.
There were no movements or joints angles a dog can't make. You could see the dog make balance checks and the muscles in her thighs contract. The shadows on the ground matched. During swoon you could see the dog put its weight and the mans arm ,he took hold of the leg and braced the dog with his thigh to the ground. The back legs moved like you would expect a dogs to move as it went to the ground.
If it was a fake it is a good one.
Plus here is another video of the same dog. Doing the same routine.
http://www.youtube.com/watch?v=8MUhb00kiXs&feature=related
and she got distracted halfway though by the ladies on the couch.