There was conflict between the dogs when the group of them started attacking the one dog. It started a huge problem when they killed the dog and Spitz was laughing about it. It is suspenseful because you don't know whats going to happen next. When they all started looking at each other it brought up suspense.
Buck was going into his nest and did not see Spitz was there. They started fighting. They were trying to kill each other by slashing their claws into their skin. Buck knew it was to the death. It had suspense because you don't know whats going to happen to them. If Buck could die or Spitz could die. And another thing for suspense would be that when Spitz comes out of no where and starts to attack Buck.
When Buck was in the water and Francois saved him. Spitz tried to attack Buck. This was suspenseful because Buck could have drowned.