I think that dog breeds are naturally adapted to do certain things, and that inherant quality will come out in almost any breed of dog. If they are a sheep or cattle dog, they will often heard the other pets, and even small children around. I had a tiny Queensland Blue Heeler that would run behind my Great Dane, and snap at his heels if he lagged behind when I was out riding my bike and the dogs were following along wirh me. At first, I couldn't imagine why Caesar would jump and yelp every so often, but thought he must have hurt his foot on a rock or something.
When It continued; I watched him closely to see what was going on, saw him lag behind, and Merle nipped him on the heel and made him jump to catch up again.
So, I think it is partly the training that can make a dog dangerous, but if they do become agressive then the natural inclinations will take over, making any kind of a bull dog very dangerous.
