I've only had ONE runi in with a semi agressive dog - and I blame the owner.

Back in college, before I had a job, I was taking the bus home from work. One the walk from the bus to home there was a house with a dog that everyone KNEW was agressive. Well, that day, the owner of the house left the gate open - that dog came out that gate snarling and charging

Now, I DID say I was on the way home from work - as an ironworker! My fid wrench was in one hand, and my ball pean hammer was in the other before you cold blink, with my tool belt over my arm as a block - luckly I had enough warning to put my back towards a parked car! I was about to feed the dog the wrench while bashing it with the hammer when the owner came out of the house, grabbed his dog - an YELLED AT ME for threatening his dog!! I told him that he was lucky if I din't press charges, and that in about another 2 seconds he would have had a DEAD dog, and he better take better care that it did not get out in public and threaten me again

I love dogs - that was one of 2 dogs I've known that did not reciprocate. The other dog liked MOST people, just did not like ME (NO clue why - it took an immediate dislike, and never got over it)