Hello Jacqueline, I'm Dr. Deb and will do my best to help you today.I'm sorry for this concern for Phoebe but I hope I can reassure you that her behavior is completely normal after a surgical procedure especially if it involved general anesthesia. Many of the drugs used will have the side effect of drowsiness for several hours so I wouldn't worry about her if you can't get her outside to urinate or to defecate tonight.She may still be a little unbalanced/sedate tomorrow morning but she should be able to walk much better, especially if you assist her with the towel used as a sling.
Of course, Tramadol can also cause sedation/balance issues for some dogs; if she's been prescribed this medication for several days and this behavior continues, then you may need to discuss discontinuing it with your vet. I hope this helps and that she's more like herself tomorrow. Deb