Just a brief update. Oscar came home from the vet's late yesterday. He is no longer on tramadol for his arthritis pain and I can see he is having trouble getting around. He is exploring, though, and lying in his favorite window. He is also eating and drinking.
The vet told me that he isn't "quite right" in the noggin. It might be feline dementia or a brain tumor. I'm happy that he is home with me but feel overwhelmed on how to best help him be comfortable. Any respectful advice on dealing with a senior kitty arthritis and dementia is welcome.