@testament You know, I am still grateful that I took him to the vet right away even though it wouldn't have made a difference either way. I had a deployment scheduled for the early hours of next morning so I was planning to take an afternoon nap, and only noticed Roo was kind of feeling sorry for himself but that could have been... anything. A hairball. Just being moody. I could have just left it there to see how it goes.
I'd have been so guilty if I had. Even now I am, and there was nothing I could have done at the point he had shown any symptoms. He did come to me to make him feel better, and I didn't. Now my cat is dead.
But at least I tried. I can't imagine how it'd feel if I hadn't.