It is so very hard to face life without them, but the decision has to be made for them, not us, and even if he fights back now, how long will he have, and what quality? This is what I had to think with PEbbles, as her issues were getting more frequent and each one was worse, and I couldnt' have lived with myself if I had pushed her her to get through her last battle, but then the next one was so much worse - we had no idea what was causing it, like you dont, which makes it harder, but I couldnt see her keep suffering because I wanted to keep her.