Manuel a Gardener sells Buck to Perrault and Francois to gain money and support his family.
Buck viciously killed another dog at the camp, named Spitz, when they were trying to capture the same rabbit.
Come on Buck.
Buck becomes the leading dog after displacing another one several times out of the lead dogs position.
Perrault and Francois sold the dogs because their orders were changed. Although, Francois wasn't too happy this change.
Here are the dogs
If you strike that dog again, I'll kill you!
Hal was beating Buck and the other dogs, because they weren't pulling the slays fast enough. But another gold hunter named John Thornton saw and warned him to stop.
Their friendship grew more everyday, and they eventually shared love for each other. John Thornton and Buck were companions forever.