You have my sympathies. It's a very difficult decision - one I've had to make too and never easy. When our old cat George was ill, after several weeks of 'treatment' at the vet we used then (not any more - we have a better vet now), one day I looked into George's eyes and there was something different. It is a look I've seen in both animals and humans when they're about to pass to the other side. It's almost as if the light of life goes out. The eyes lose their sparkle and go dull with a faraway look, it's as if they're seeing but not seeing. It is something you'll recognise straight away - and never forget. It's something that's extremely difficult to describe. This is why when my 16 year old cat Lucy was very ill just before Christmas and nearly died, I knew I had to give her every chance - there was still fire in her eyes. Fortunately, with good vet care and lots of TLC Lucy made a full recovery.
My heart goes out to you at this very difficult time.
My heart goes out to you at this very difficult time.