How are the dogs treated by the scotch half-breed? How does this become important to bucks future

The Scotch half-breed treats the sled dogs fairly though he is equally hard on them. We never find out the name of the Scotch half-breed perhaps because he simply represents unnamed authority without excess of good or bad traits. There is no emotional involvement between dog and owner. Perhaps this is why Buck longs for something more out of an owner. He just doesn't want to complete the task; he wants a serve a master that he cares about. I think this foreshadows the arrival of John Thornton into his life.

How are the dogs treated by the Scotch half-breed? How does this become important to Buck’s future?