I am so sorry to hear the diagnosis is cancer. I've known more people and pets with cancer this past year than ever before. My dear heart kitty, Morgan, got an oral fibrosarcoma form of cancer earlier this year. I did just as you are doing. I kept him with me as long as he was not suffering at all and enjoying life. Then I had to let him go. It's the greatest act of love. That was 3 months ago today. I miss that boy every day, but I treasure those times we had together even after the diagnosis. Once he recovered from the biopsy procedure, he never knew he was sick. That's how I'll always remember him. I hope you have those good memories with Duke as well. Many hugs to you.