I decided that maybe it was the anti-inflammatories (that he was taking for his knee) that was making Ray feel bad. So I stopped giving them to him.
Noonish, I noticed that he seemed to be perking up. When I made myself a bowl of popcorn for lunch, Ray jumped up on the couch next to me and put his nose in my face, literally trying to steal the food from my mouth. I pushed him off the couch with my forearm. Ray immediately used his usual tactic of coming at me from a different direction. He hopped his front feet up on the couch and stretched his neck out. I "Bah"ed and told him "off", pushing him feebly with a hand full of popcorn. One piece popped out of my hand onto the floor. Ray hopped down and started sniffing around (how did he know that one piece fell on the carpet? can he hear a piece of popcorn hit the carpet? did it leave a scent trail as it flew through the air?). His ears were deployed in full Dumbo the Elephant mode as he sniffed, sniffed, SNIFFED. He was getting farther away from the piece of food when I noticed that the lamp and wireless telephone docking station were silently sliding across the end table. I quickly set my bowl of popcorn on the coffee table and grabbed Ray's collar. He was tangled in the phone and lamp cord. I removed the cords from around his feet, replaced the phone and lamp, and turned just in time to see his head in my bowl.
I guess he was feeling much better.