ladysprite came over mid-evening; thank heavens she did -- I don't think I could have coped with having it done in a sterile lab room by a vet without her bedside manner. I don't really know how she manages it, given that she clearly feels each one, not shutting her feelings off as I'm sure some vets must. (I was a tad offput by quite how clinical our usual vet's partner was when I talked to him yesterday; I can understand it, but it wasn't exactly what I needed then.)
After the necessary paperwork, the process itself was relatively calm; he complained a bit, but only half-heartedly (a sign by itself of how weak he'd gotten). We set him down on the pink towel we've been keeping in the carrier as a touchstone during the relatively frequent trips to the vet this year. She examined him, confirming that he was as sick as we thought. The dehydration was fairly serious, the cancerous mass had gotten quite large, and kidney failure was beginning to set in. So she gave him a sedative so that he would be calm for the final injection; we skritched and held him a bit as he got tired. Then she shaved a bit of fur from his right foreleg, and we held him as she gave the shot, keeping up a steady soothing patter as she did so. We both sobbed like babies -- if anything, it was even more visceral an experience than I'd expected. That said, I suspect it was good for us: as msmemory put it, we got much-needed closure.
My only error was looking into his eyes a bit too closely. ladysprite had warned us that the eyes don't close during euthanasia, and that that freaks some people out; in retrospect, I should have paid more heed to that warning. Unlike the stereotypical human death in movies, there was no clear unfocusing or anything like that -- he just stopped moving. It felt less like he was dead than just very distracted -- like he could have snapped to alertness again at any moment. If she hadn't been listening to his heart, I could have easily believed that he was still alive. Those eyes may disturb me for a while, until the image fades.
We sat quietly for a few minutes, still crying a bit and stroking him. Once we were done, and dealt with the final paperwork, she swaddled him in the pink towel and took him away. The two of us just hugged for a very long time, and then went back to the mundane world. Despite not moving out of the living room, the sensation of moving from ritual space to mundane space was very dramatic, and quite intentional on both of our parts -- we needed to distract ourselves a bit, to immerse ourselves in trivia rather than wallowing too much. So I brought in the laundry as she did the dishes, we both gave Merlin (who slept through the entire proceedings) a good skritch, and went on with life...