This is absolutely disgusting! And non muslims ask "Why do you guys hate the Israelis so much?" .
As a side, police / military dogs are trained to attack moving objects. In this case, the dog was set on one lone individual, so the dog had a specific target. In crowds, DON'T MOVE. The dog will press on to another target.
Such dogs are also routinely trained to heed commands in a language not normally spoken in the area. Otherwise, someone other than the dog's handler could confuse the animal enough to allow time to kill it or escape from it. The most common language used for animal conditioning is German (Deutch).
wa salam