Here's the deal - Aggression is bred into certain breeds of dog - like it or not. You CAN breed for personality traits just as you can for physical ones.
I'm not a "dog guy", but I come from a dog-crazy family, and my better half's folks are registered, REPUTABLE breeders of Old English Sheepdogs, some of the best in the world. I've spent a lot of time at dog shows over the years, so I'm not totally ignorant of canines.
These already naturally aggressive dogs are then often trained by idiotic owners (who know absolutely NOTHING about dogs) to fine-tune their aggressive tendencies, to increase the owners' "machismo". Now, even though the dog may be "great with the kids", it's usually not a family member who gets hurt by it.
Just recently a mail-carrier was mauled by two pit-bulls who went right through a screen door at her, knocking her down causing her to break both fore-arms, and then proceeding to tear at her face. She ended up losing an ear and badly scarred.
I'm sorry, but this sort of thing is totally unacceptable, and it's becoming more and more prevalent as the popularity of these "back-yard breeds", as I like to call them, increases.
If you've ever really taken a look at the statistics on dog bites/attacks, problems with captive herps pale into insignificance, yet most places won't allow even small boids, but any moron can own a dangerous breed of dog.
And just to make a point - yes, ANY breed of dog can attack, depending upon circumstances. Apparently a toy poodle killed a baby while left alone together for a few minutes.
(I'm sure this post'll upset SOMEONE).
Simon R. Sansom
"PEARL - The best reason to play drums"