I spent a lot of time with him before the howl just laying on the floor of the living room with him. He couldn't see me, he couldn't hear me, he barely knew who I was, and he barely knew I was even there. When a dog gets so old that they cannot even wag their tail anymore, you know it's their time. I even contemplated putting him to sleep because of his condition. But I guess it was his time anyway.
The circumstances of his death were thus: He went to sleep and never woke up. Just the way I always hoped he'd go. He'll certainly be missed.