There's a video going around on youtube via FB showing a coyote trying to take a small dog right on the driveway of their house. Just as you're thinking that little dog is done for, here comes a Rottie, who hits that coyote in a cloud of dust and runs it off. If I can find the link I'll add it here. Never underestimate the lowly coyote, they are fearless.
Here it is.