I agree with everyone who's told you that Your dear friend and fuzzy brother was not in pain or you would have known it. He had exactly what he wanted a safe place that was familure to him to cross over. A place where he knew you were close by if he wanted you and therefore was all the safer in his heart.

I betting he knew it would be very hard for you to take him to a final vet visit and then have to come home alone. He chose to go out with his best version of dignity. Your love has added to his tail name, and he is waiting for you when you get there.

((((( Hug ))))))