Bucks owners Perrault and Francois, They were fair but sometimes abusive. For example they threw clubs at Buck when he went to position of leader. This shows they thought they could control all the dogs thoughts and actions. Their arrogance lead to their death. Also they let Buck and Spitz fight to the death. Their killing their own dogs just for the pleasure of entertainment. They killed the dogs that were going to get them to the Klondike. They're a little abusive and cruel.
The next owners Buck had were Hal, Charles, and Mercedes.