That jerk deserves a good beating with a steel pipe and starved for a week!!!! He is just too stupid to live!!!!! I'd report him to the authorities.

What a sweet little dog she is. I think with a little work, patience and re-introduction might help the situation. Afterall, look at the environment she came from. She was abused and shows all the signs. You might want to alert the Jack Russel Terrier Rescue and let them know. Here's a link to a rescue organization in the midwest. Maybe if you call them they can tell you where in your area they might be located.

http://www.gravid.com/jrtrescue/

I hope it helps. And, I hope you don't even THINK about returning that sweet precious little dog back to that asshole! Did you consider calling his ex-girlfriend to see if she'll take her??

Good luck and let us know how you make out.