I agree with Gary. Take a wait and see approach, as long as he's not in any pain. Sometimes cats can live long lives with certain conditions (MooShoo lived almost 11 years with a bloodclot). Certain conditions can also be corrected or maintained with different kinds of food. Ask your vet.

If and when the time comes that you have to make that very difficult decision, make it with your head, not your heart. Also take into consideration what his quality of life will be if you try to keep on sustaining him.

I had to do that with my RB Mollie Rose. She was my very first cat and was 16 when I had to make the decision. She had severe kidney disease and had lost 4 pounds in less than a year. I noticed how skinny she was. Then one day she was laying at the water fountain yowling. I ran her to the vet and they kept her overnight, and did tests. He told me there really weren't many options unless I wanted to spend $1,000 for an ultrasound. I would've sold my soul if it would've made her whole, happy and healthy. But it would not. I came to the realization it was time. She lived a wonderful, pampered 16 years and got me through so many difficulties and tragedies in my life. I will never forget her.

I also believe that no animal should die alone. So, while the vet gave her the injection, I petted her, telling her I loved her with all my heart, and to go to the RB and be happy. LES right now.

You and Irwin will be in my thoughts and prayers.