Kill the put bull.
“Pit,” not “put.”
I found that a 12 guage loaded with bird shot will NOT kill a pit bull unless you shoot him three or four times. Now I use a minimum of #4 buck or bigger.
Why bird shot? Because many of the home defense books in the past recommended it for home defense as it will not go through several walls.
Surprise surprise! It won’t go deep enough into a pit bull either!