I would absolutely take him in. They need to check his palate and make sure there's no swelling. My two had the surgery a month ago, and neither one panted while on Tramadol (not sure what the side effects are though).
eta: I only kept mine on tramadol for a total of 2 days. It was so strong that it sedated them way too much and made me uncomfortable. So I cut the dosage the second day.