If you hit a dog in a neighborhood you should stop and see about the dog and see if the owner is around and apologize to the owner of the dog and help them move it out of the road way.
If on a rural part of the road you should still stop and see if the dog is okay or not and get it out of the road if possible.
If no one is around then the best you could do is get it out of the road way and then get into your vehicle and leave.
There's not much you can do if no one is around.