Answer:
If a husky is injured during a fight, the whole pack jumps on him.
Step-by-step explanation:
This is the sentence that best summarizes this passage. The main purpose of the passage is to explain the behaviour of huskies during a fight. The author tells us that huskies generally do not intervene during a fight, unless one of the combatants is injured. In that case, then the whole pack jumps on him. This is the sentence that contains all of this information.