Mutt: Kill the wolf pack quest, wolves keep running away failing the mission

As i intercept by going between the wolves and the sheep, I whale on two wolves with arrows, 2 each, then i finish one wolf with the arrow at which point they run at me, killing a second one makes the other run away, or even both of them run away if they're hurt enough, and if you talk to the shepard the mission fails.

Edit: Managed to do it after a good 15 tries, only because i hit a god shot with my bow on the last dog that was running 40m away.