Around here, the good ole boys use the excuse that it's not their dog but a stray that they felt sorry for so they fed it a bit.
I got taken down by a border collie a couple of years ago. It ran out after me and right in front of my bike. I hit is and went down. This was like 1 week before I was flying to Banff to ride the upper portion of the TD route too. As I got up off of the pavement the dogs owner came running out and the first words out of her mouth were "OMG, are you alright?" She was genuinely concerned for my well being.
Other than in a case like that, my rule is that if your dog bites me or takes me down, you will have a legal problem.