Dude, I have hit oppossums, raccoons, squirrels, CHICKENS, ground hogs, birds, deer, cats and 1 dog. The deer will fuck up a car. The non-domesticated animals, I will do my best to slow down for, but will not put myself in danger of running off the road, and fucking up my car possibly injuring myself.
The dog I hit, I felt absolutely shitty for, but I couldn't avoid it. It had no collar and was out on a back country road. The shitty part was that it was likely someone dumped him out along the road, he had no clue where to go or what to do. Shit like that happened all the time back home. Theres no bad dogs, just bad owners.