In chapter 3 of call of the wild

The team is attacked by wild sttarving dogs. Later, despite these hindrances, the team sets out on the toughest part of the trail. Francois is worried that the dogs will develop madness because of their wounds, but Perrault refuses to coddle them. It takes 6 days for them to travel thirty miles. Occasionally they break through the ice, and the dogs have to be thawed by a fire.