Pit bulls require owners of very strong character. My neighbor has had several, and he is too mild a person to own such a dog. His wife is such a nut about dogs, if he were to die, she would probably have forty dogs in the house, rather than the six or so she has now. And they are not little yappy dogs, either. Some years ago, she called me when their pit bull, who was about seven months old at the time, turned on one of their older dogs. As the older dog had been beating up on the pit for some time, I can't blame the pit for what it did. Its jaws were locked on the older dog's muzzle, and I had to get it off. I did so, but I had a cocked and locked .45 in an unsnapped holster when I separated the dogs. The neighbor was hovering over me at the time, and I would not have liked to shoot her dog in front of her, but I also have grown fond of my own self in all these years, so I would have apologized afterward.
We live in an area between a city and a popular lake. A number of people take advantage of the ride to drop off dogs, and we have had some problems with roaming packs. Most of us carry when in the field, because of the threat from the packs. That same neighbor went looking for his cat and was set upon by three large dogs, who had run the cat up a tree. He was unarmed, but managed to hit the lead dog, which was charging him, with a stick he picked up off the ground. This turned the dog. The cat jumped out of the tree, and another one of the dogs caught it and took off, the other dogs following. We went back, armed, but never found the dogs or the remains of the cat.
To me, the owner who tells me that his dog would NEVER do anything like that is a real red flag. It's time to get out the shovel and check to see what loads you have in the gun.