There is an excellent book 4 Seconds Until Impact by Bruce "Buckshot" Demming documenting many wild animal attacks.

My advise to those wanting to use a knife for defense against such large animals is to use a nice small knife. That way it won't hurt as much when the bear (or whatever animal) shoves it up your butt.

Most folks suggest a firearm which sounds good but I think that a good bear spray is better. The Alaskan Sate Police use UDAP brand bear spray.

In my area,a couple of years ago,over a period of one year,6 folks,while walking their dogs were attacked by coyotes. Three dogs were killed,three injured. And this was in suburbia not the woods.

We have a serious coyote problem here.

Wayne