Several years ago I had a co-worker whose brother was carrying an LCP while out on a morning run. He heard a dog running up behind him, turned and realized a Rottweiler was charging him. He was able to draw his pistol, and fire two rounds at the Rottweiler once it jumped and was in midair.

My co-worker didn't know where the hits were, but he said when it landed it was DRT. I don't think he knew what ammo was used, either.

I don't know if the outcome would be the same every time, but it worked that time.