NOTE: If you are using a mercenary or pet, you must get in the killing shot on the Warwolf Matriarch, not your pet/mercenary, for you to be able to abduct the pup. This also seems to count in a group: the one with the quest needs to be the one to have the killing shot. This update is group wide so, as long as the member who had the kill loots the pup, the rest of the group will get the update.
Find and retrieve an abandoned war wolf pup in the Storm Gorge at ( 897, -366, 899 ) /waypoint 897, -366, 899. You will be attacked by one or two Warwolf Matriarchs as soon as you click on the pup. Although the wolves are not mentioned in your quest journal, the pup can only be retrieved once you've killed them.