Chinchilla Limp

Hi! I recently got a new chinchilla, the other one ended up hurting him worse than I thought, they were immediately separated at sign of distress, but now when he walks he is letting the back side of his body drag. I took him to the vet this morning, he got pain medication and an X-ray, no broken bones or anything, so they sent me home, said he most be sore or something. He doesn't balk at me touching him, and he is eating and drinking, he was even chewing on some wood in his little hide...

Chinchilla Limp