While going through the Companions quest line in Skyrim, I received an Animal Extermination quest to kill a saber tooth tiger at Greensprings Hollow. I have gone to this location several times, and have killed 3 tigers so far. Unfortunately none of these tiger kills seem to forward the quest line. I can't move on with the Companions line until this is completed. I am wondering if because I had previously discovered Greensprings Hollow if that didn't make a glitch where I cant complete this quest. Any suggestions or guidance would be appreciated.