I just stumbled on this thread and was ecstatic! I have been wondering how Zane was doing for some time now.
I know exactly how you feel here.
You remember my Lucas?
I came to several close calls on putting him down and the vet was absolutely no help in treating him.
He was a little different than Zane, as he could walk, but could still not go out with the rest of the flock as they would surely have killed him.
I went back and forth for months trying to decide if he had a good quality of life or not.
As most know, he ended up living in the house, with his own room.
He seemed very content in here. I recall letting him out in the yard a few times, but I had to sit out with him or he would want right back in the house to be with me.
He didn't seem to miss the flock at all and seemed to think of me as his "flock".
The decision is ultimately yours, he is your bird and you know him best.
I finally came to my decision, decided he seemed to enjoy the quality of life that he had, so I let things take a natural course with Lucas. He was eating and drinking and seemed content.
In the end, he let me know it was his time to go and that he was ready. It was late in the evening and I couldn't take him to the vet. I made him very comfortable. That night he slept on the little sofa next to my bed, and he woke me in the middle of the night.....I almost wonder if he was waking me to say goodbye.
I sat next to him, he cuddled up to me and I held him close and then he was gone.
That boy found a special place deep in my heart.......
....sorry...need a moment....
I know you are going though a very hard time trying to make the right decision with him. All I can say is, follow your heart and listen to Zane, he will let you know.......