Lovely,
As hard as it is to let go, sometimes you just have to. A few years ago, I had two 18 year old cats and my forever pup, Timber, who was just starting to get on in years.
My two cats, one after the other became hyperthyroid and senile at the same time. I had to put the oldest down first. It broke my heart and I could not even do it myself. I was already seperated from my ex-husband and he did the deed for me. She was declining so rapidly and it was evident that her quality of life was no longer there. She just did not seem to care anymore.
My second cat, Spud, went nuts! One day she was fine and then the next day she went crazy. My "new" partner came over one day - and she knew him well - and she went down into the basement and started to self-mutilate herself. I went down to see what she was doing and found blood everywhere. She was literally tearing the skin off her legs. It was time. This time I went with her and I'm still teary about her last moments. She was again the gentle soul that I knew as she quietly passed away.
With Timber, he became ill very quick and very fast. He was diagnosed and died of a tumour on the same day. But even when I heard the diagnosis and the vet walked me through the possible treatments, I knew that it was not the way to go. At the time, I still thought I had some weeks but as it turned out, I had only 1 hour.
In the end, you really have to think about your pet and not yourself. It's a tough call, because many of us think of our pets as family and would not dream of euthanizing a human relative. It is, in some respects, an ethical decision, but one that I'm prepared to make.
If treatment, surgery, whatever will signficantly extend the lifespan of the pet, then I'll bring out my checkbook. But if the end is inevitable, I'll hug my baby close and hold vigil as he quietly passes away - without further pain.