Rex is a beautiful old boy. I'm so happy to know that you are there for him, being his faithful companion during his old age. All the way up to his final moment, he will be loved by you.

I know a few people already said it sounds like epilepsy. I think so, too. Your vet might consider trying meds, even though he hasn't done any tests. If it worked, that would be great. If it didn't, no harm done.

I don't thinks seizures would be uncomfortable for him. I know that people don't even remember them, after they're over. It's more painful for you, when you're watching.

My thoughts are with you during this very difficult time.