Why didn't Karana shoot the dog's that that were attacking Rontu in Island of the Blue Dolfines?

The wild dogs on the island grew bolder after the battle with the Aleuts for two reasons. The first is that village dogs whose masters were killed joined the pack. The second is that a large, gray dog with yellow eyes had become the pack's leader. This dog is bigger than the rest, and a different color (most dogs on the island of the blue dolphins have brown eyes and fur). Karana believes that the gray dog is an Aleut dog left on the island after the battle.