About a month ago I went into our yard at work after hours to get some glass. We have a guard dog (german shepard - biggest one I have ever seen) who no one is allowed to know other than 4 'masters'. I have been out with one or two of those people when the dog was out and everything was fine. This time I ppeked out the door to make sure it was alright, and when he came to the door to let me out the dog came in and grabbed me by the arm. Scariest 10 seconds of my life lately. My wrist swelled up to the size of my forarm instantly and I had gouge marks in my wrist. Luckily because he is an actual attack dog i think they filed his teeth down. Me and the other guy basically had to drag the dog and my arm to the door, and we somehow got him out and my arm out of his mouth. We told the trainer about what happened and he basically said I was lucky he didn't go for the face or my throat, as he is trained to attack anywhere.
Other than that I was also attacked by a dog when I was 6 in Ireland on my Grandpas farm and had to get 20 stitches to close a deep wound on my arm.
You would think I would hate dogs, but I can't wait to get one.
edit: The pic of my arm was a couple of days later when the swelling wasn't so bad. The dog didn't do that much damage actually other than a little nerve damage. Basically I was lucky and we acted fast