Studies show that small dogs like Chihuahuas, Miniature Poodles, and Miniature Schnauzers are more likely to be aggressive than medium-sized and large breeds. However, because of their size and strength, Pitbull and Rottweiler attacks are by far the most dangerous ones, with the highest number of confirmed attacks resulting in injuries and the highest fatality rate. A study conducted by Dogsbite.org over a 15-year period shows that 65.6% of fatal dog attacks in the U.S. were by Pitbulls followed by Rottweilers and German Shepherds with 10.4% and 4.6% respectively. There are other factors...