Elderly dog shaking head?

I have a 14 year old chow mix that's shaking his head periodically and leaning his head to the side a bit. Pretty obvious his war is bothering him. It's night and he doesn't seem to be in pain (he's a big baby, he cries when he gets a flea bite or a sticker). I cleaned his ears, the one that is bothering him was much dirtier than the other. He has no discharge, blood or smell coming from it and I gave him a Benadryl just in case. (He has some slight allergies and he takes Benadryl from time to time). I was just wondering if there's anything else I should watch for or do for him. I plan to make a vet appointment tomorrow if it's still bothering him, but I worry because he's so old. Just want to make sure I'm not overlooking something until I can get him in to see his vet. (He's been to the same vet his entire life and I try to only bring him there because of the medicine he's on for his arthritis)