Comment I owned one (Score 2, Informative) 85
I had a rottweiler mix that lost his front left leg to osteosarcoma. At slow speeds, he would move kind of like an inchworm, hopping his remaining front leg forward, then jumping both back legs forward, wash, rinse, repeat. He could do it while keeping his head on the ground, say following a scent trail. At higher speeds (and even after the amputation he was faster than his brother) he would do a run in which his two right legs would move, then the remaining left rear would move. His head would bob up and down as he ran. Oh, and when he peed, he would lift his left rear leg, and balance on his two right feet. BTW, the cancer came back and got him a year after the amputation - bone cancer of the back left leg, and we didn't want to try him as a two legged dog, though I understand some of those get around as well.