Good update:

Mom says Shiney is still not quite himself, but he is under his favourite blue blanket on the couch and when Mom puts her hand under there he rubs his head against her hand and purrs!

He is also playing!

The vet called and said if he continues to do well they'll extend his prescription of painkillers. It's not metacam - it's buprenorphine, an opiod agonist: http://www.vetinfo.com/buprenorphine-for-cats.html

Maybe he has some arthritis that was really bothering him. Who knows?

I am just glad he is returning to his normal self. Mom says the amount of liquid med is so small that it's easy to medicate him.