At the clinic I work at we usually recommend you keep dogs separate for at least the rest of the evening/afternoon and next day if necessary. I swear it AMAZES me how fast dogs bounce back from things like this!
Obviously it depends on the dog, but we've had some dogs with several teeth pulled who are looking for food the same evening! By the next day when they are allowed food again, they will chow down as if nothing happened!
Good luck on the bloodwork and the surgery!