I would just go back to square 1 with Chance by confining him. You can definately keep Remmy out while Chance in confined. But is there any place you can confine Chance that Remmy cannot get to? I would hate for Remmy to torment Chance through the gate or crate or something. It also could be a result of the surgery. If it is still an issue at your next vet visit, I would definately mention it to him.
Good luck! I am sure you will get everything worked out and back on track in no time!
