Pit bull breeders have confessed to interbreeding i.e., breeding father to daughter and mother to son. This makes for an unstable, unpredictable animal. I know of a case involving a woman who lived next door to a pit bull owner; she had a seven year history with the dog, no problems at all. One summer the owner took a vacation and asked his neighbor to feed and water his dog.

She agreed, days one through three, she put the food down, pet the dog, the dog wagged his tail, ate the dog food, no problems. Day four she put the food down, pat the dog, dog wagged it's tail. She turned to walk away and go back to her home. She said she got about ten steps and then heard the dog coming for her. The attack came from her rear. When I saw her she had over 120 stitches in her leg from the attack. The doctors at the ER told her she was lucky she hadn't been killed by the vicious pit bull attack.