I love animals - especially dogs and cats.
But I would have kicked that son of a bitch flat up against the wall about 1.2 seconds into his first lunge.
Yeah, I would have smacked it.
I've been charged by many dogs in the past. Thankfully none have gone for it.
Ever time I have, I put my keys through the fingers in my fist, drop back with my left arm out front as a guard and wait for it to bite. If it goes for the arm, the first action is to kick it as hard as I can in the abdomon and the second is to go for it's eyes or throat with punches loaded with keys. If I manage to knock it down flat, I will stomp it's throat till flat. Any dog that tries that with me will be dead, and I will cry a lot, and go to the emergency room with it's collar in hand, but I'll be alive.