Growing up, my mother's friend had pitbulls, the real ones, not just dogs that kind of looked like one. Pappy, he was a real pit bull. He fit every breed standard in appearance and he had all the typical breed personality traits. You know, like Petey. Friendly, playful, loving, loyal, and determined. He also had arthritis. In all his pain and misery he took all the kid lovin' he could get, and would still dive in the river to pull up the *exact* rock you threw in. He wouldn't come up to breathe until he had it. His owner never had to worry about him, he was a good dog in every sense of the term. Then Pappy died and he got Sarah. She was another dog all together. Stealth and petite, absolutely gorgeous, and dangerous. He didn't kid himself, he knew it, it started showing early. When he worked or had company she was locked in a large kennel with signs. He made all the kids, neighbors, and company aware of her. She spent her time alone with him in the house, on leash, or in his truck when he went somewhere. She was the possessive and territorial dog Pappy never was. Still good and loyal for her master, but so loyal she was a danger. He never messed around with her capabilities and she was never, ever given an opportunity to bite. That's what a good owner does, and it makes a difference.
All those owners who say the dog just snapped without warning, they lie. There's always something, some hint either in personality or in the current atmosphere to give warning. Be it an annoying child(pulling ears, etc), forming a pack with other dogs, food, noise, or pain, it's there, and it should be the flag for an owner to remove the dog from the situation even if the dog has never reacted in the situation prior.
Dogs being allowed to run free and form packs is one of the most dangerous things anybody can allow a dog to do, period.
