Why does the pitbull breed have such strong looking muscular heads/jaw?

I recently took in an adorable pitbull mixed puppy, and have been looking at pictures online of others. I have noticed that a lot of them have very…

ASKED BY Toda on 3/7/08
TAGGED pitbull, pi, pitbull, head, big, muscular, exercise, daily, puppy, pup, puppies, strong, nutrition, fit, muscles, baby, dog, kong, ball, kongball IN Breeds 0 ANSWERS CLOSED