I lost my beloved Buffy on Mother's Day. I took her to the emergency vet on Saturday morning for an issue which resolved itself while she was there, but they said, "while she's here, why don't we just do an x-ray and see if anything we don't know about is going on?" and they gave her a pain shot.
It was more intervention than she could tolerate and she was not the same cat when she got home. I waited 24 hours in case she improved--sometimes before after pain meds or being hospitalized, it took her 18 hours or so to get back to herself--but not only was she not herself, but she was hunching over (a sign of a cat in pain) and occasionally putting herself in her carrier to hide (a new behavior). She did drag herself out to the porch to lie in the sun for a while and I did get a few minutes of purring from her when I was lying by her side, but it seemed kinder to put an end to what was clearly suboptimal experience and the sooner the better. I tried to schedule an at-home euthanasia but the earliest I could get was Tuesday, and I didn't want to wait.
I have now been pet-less for a week, which is the longest period in 29 years. My head's intent is to adopt another two cats later this year, towards year-end, but who knows what my heart will end up doing? I'm still kind of numb and in shock and grieving profoundly. I have loved all of my pets, but there are some who touch you more deeply. A decade ago, Henry was my heart hound, and Buffy was my heart kitty for the past 9+ years.