I think he's OK - think I am gonna cancel the appt. I hate to cost them a vet trip for nothing. - He isn't all hunched over in the back like Logan got when he was plugged up... and boy could Logan get plugged up!
I think the stress of a vet visit would be worse for him than just keeping him under your own observation.
When my family would care for my future bro-in-law's old rottie, he would normally pine a few days for his dad. During this time, he wouldn't eat much. After 2 or 3 days though, he'd be right as rain again.