RIP dear sweet Jock -- I went through the same thing with my RB Goldie earlier this year. The tests were necessary to confirm my suspicions. The vet and I debated on doing more extensive surgery, but we opted not to as it would have been more traumatic for dear Goldie.

It's a difficult decision, but the right one. Jock is now out of his pain and you spared him days, weeks or months of suffering. He is now playing, pain free and healthy at RB. God speed dear kitty.