And ANY dog, regardless of breed, can become dangerously "dog-aggressive", for lack of a better term, when they get into a situation with another dog where they feel threatened or provoked.
Personally, I rarely blame the dog (the one time I was bitten as a child, it was a weimeraner, it caught me on the lip, and my mother reamed me out for getting in the dog's face after I was specifically told by her to leave the dog alone. My fault for provoking it, like the one major horse bite I've gotten was my bad for not paying attention.) You put a bunch of dogs in a big mix like a dog park, eventually someone's going to get in a fight. Hence my thinking dog parks are stupid ideas--my dogs are not children in need of "play dates" or a nursery school.