Do all bites mean a dog is aggressive?

An email I got today reminded me of when Deena's terrier mix Jake bit me. We were at the dog park and a boxer who I had known from a few months earlier came in. He immediately decided that Jake should be dispatched or lunch or something. The only one that got hurt in this was me. I grabbed Jake to get him out of th...e dog park and he whipped his head around and bit me. I'm sure he thought it was the boxer and reacted still trying to just get away.

The email this morning was a very sick dog with, what appeared to be, multiple injuries to at least two legs. He redirected on his savior during the process of trying to get him into the truck. Please don't consider this aggression or dominance or anything but what it is. A scared, injured dog who has no clue that he is being helped even while he's being hurt because the human put hands in the wrong place.

There are many reasons why a dog aggresses or bites. Very few of them have to do with dominance, most are from fear, and some like this poor guy, from pain.