Walrus

Chihuahuas as someone mentioned down below do have a highly reported dog bite. I believe they are the highest. And yes, they can do damage, especially to a child. Most owners don't report bites if it happens in their household to one of their own. So you'll never really get the full picture of things. Even friends who get bit by their friend's dog often don't report the bite in fear of alienating their friend.

So what we're left with is mostly data from random dog attacks by people the owner doesn't know. The Pit bull attracts so many unsavory owners. You'll rarely see a thug owning a Poodle. The media also likes to report Pit bull attacks because they know it will make big news. No one cares when a Golden Retriever bites someone. When you see a Pit bull wearing one of those big chains or spiked collars you know there's trouble blooming. Also, there are a high number of reported Golden Retriever bites. This surprises most people. The breed is often considered "America's Dog." But there's been a lot of bad breeding in the past few decades and this has produced a high number of bad blood lines. When you don't breed with good and responsible selection criteria that's what happens.