Cane Corsos, Dogo Argentinos, Presa Canarios, Fila Brasileros (sp?), American Bulldogs, Bull Terriers, Staffordshire Bull Terriers, Heelers, Mastiffs, Labrador Retrievers....

*SIGH*

This list goes on and on, why not just say that every breed of dog is dangerous? Because in reality, they are if not properly socialized and trained. A nipping, biting puppy at 8 weeks that isn't corrected can be dangerous as an adult. Socialization and obedience training are very important with breeds that tend to be overly dominant. All breeds should be trained and socialized, even small breeds.