Those pictures of prosthetic legs are very interesting! I guess it would make it easier for the dog to get around? All the 3 legged dogs I know seem to get around just fine, but I guess it would put a lot of stress on the remaining legs, because they have to bear more weight. I suppose a prosthesis would help with that?
That poor puppy in the video! He looked like he was getting the hang of his new "leg" pretty quickly though!