I'm still thinking that the Carolina Dogs mentioned aren't a remnant so much as a reversion. I've been told that numerous animal species,when left to fend for themselves,revert back to their basic genetic stucture very quickly. It's my understanding that swine can do it in less than 4 generations-compare a high shouldered,loooonnggg tusked,extremely wary feral boar with his barnyard counterpart and one can see just how big the difference can be. My guess is that the Carolina Dog represents something similar-a reversion to "Dog,1.0 Release",if you will. They look like pretty decent creatures to have around the place-I wouldn't mind one or two myself.
These fellas here look just like any Third World mutt. Maybe the INS has been goofing off ... again.