The issue with most wild animals is that they are programmed to survive, this is why you see or hear about historic baiting sports the wild animal is always chained. A bear is not going to stick around and try to fight 4 dogs for fun, the bear will make a determination if it is worth it, if it will get food out of it, if not the bear will run away. Just like other wild animals, I saw a video of a wolf tethered fighting salukis or something clearly enough the wolf just wanted to run away but he couldn't.