I have, unfortunately, managed to hit three dogs in my 4 1/2 years of driving. 1st was on a state highway going around a curve at dusk, chocolate lab. 2nd was on a state highway at night. 3rd was also on a state highway at night (this dog actually hit me really, it ran across my lane and into the other in front of a semi and then decided my lane was better and ran into my driver's side door).
Anyway, not once did I fail to make an attempt to contact an owner or find the dog myself. The first one I stopped a ways up and walked back to find the dog, but it was not there so I walked to a couple of houses, no answers. The 2nd I drove around the block a couple of times to find it, no dog and the third the dog actually got up and ran away as I think it was just a bit dazed. I did go to someones house, but it was dark and they refused to answer the door. How do I know they refused? Well, they looked at me through a crack of an interior door and then didn't answer.
)
I personally find it rather upsetting hitting anything and can't imagine why some people would go out of their way to inflict pain upon both animals and other people. There is, in many cases, a person attached to that animal. It's a sad state of affairs when people have to resort to inflicting pain on others to pleasure themselves.