The ear cutting was originally to protect fighting dogs wasn't it? In dog fights, dogs typically go for the ears, so it was for their protection. Obviously not an excuse nowadays. The only other possible legitimate reason I can think for cutting the ears is if they're going to spend a lot of time in water. I know floppy ears are bad for ear infections if not dried properly. Even then... Use a towel, don't cut parts of their ears off.
Our younger dog is half pit bull (according to DNA test also has Rottweiler, Doberman, and Australian Shepherd)... Looks pretty scary, but the biggest chicken in the world. She loves playing with kittens and my daughter's rats. So incredibly gentle. I trust her much more than our lab/retriever/pit mix.
