[kainolophobia]

My first idea was to build some sort of balloon/inflatable device that you drop into the hole. By affixing meat to the rope/hose, you can get the dog to climb on top of the balloon as it slowly inflates. Once you've got the dog out of the not-so-cylindrical bottom, you can deflate the balloon to the point of fitting the circumference of the hole. From here you carefully pull the dog up; making sure you stop if it's legs get caught/etc.