Mary, I know you will do what is best for Puddy. It will be difficult, but the right decision.
Why can't they live forever? I know when that time comes for me to send my Tazmoe to the bridge, I will find comfort here with my PT family. People who know what you are going through and can relate on many levels.

I will be hoping these last efforts will help Puddy feel better soon and keep her with you for many more months (heck, maybe even years!).