Try to get the dog out more these dogs need good socialization skills.Dog training is a good idea also so they get used to other dogs and people they also need a lot of exercise if they are not trained properly they will own you.The growling was just the dog showing he was scared probably or possibly approached in the wrong way.Always remember most people think the pitbull is the man/dog killer and they will never know they are the sloppy face lickers loving and dedicated dogs unless trained otherwise.This is my 1st. one also and they are great dogs they just need training in short bursts 10-15 minutes.
