Updates!
Roxy's twitching is caused by a pinched sciatic nerve.
She's being "fostered" by my co-worker Nicci. She's loved Roxy since the day they picked her up. Because of her issues with strangers, Nicci's boyfriend was refusing to let her come home. He finally gave in and now Roxy is living with them, their two kids, three cats, and another pit bull, Tinker. I'm told that Roxy and Tinker are best friends! She's great with the cats too. She still brings her back to work with her every day. She hasn't officially adopted her but Roxy won't be back to stay either.

so happy for her