My kitty is actually a surrender.
Back story is that she was adopted as a kitten by a family from the humane society. When she was about 2 years old, she developed severe atopic dermatitis. The family worked with their vet (my sister’s clinic) for a little while, and when she didn’t improve, brought her for euth - saying that the cat was just miserable and she (the owner) didn’t want to deal with the scabs.
My sister’s clinic told the owner that the proper action was to surrender her back to the humane society. So she did.
The humane society then tried to get the allergies under control, working with my sister’s clinic, but couldn’t - the humane society simply couldn’t stay on top of her meds due to having so many animals. So they brought her back to the clinic for euthanasia.
The vets (my sister and a peer) wanted to give the kitty one more chance, so they took her in as a clinic cat. And…it took a long time, but they figured out the regimen that kept her allergies under control.
As it happened, about that time I was looking to adopt a special needs kitty, so now kitty is mine. For good. 
But, in reviewing the above, I’m finding it hard to judge anyone too much - kitties with significant health issues can result in tough choices. And while it makes me really sad that she was adopted and then surrendered, again I don’t know the first owner’s circumstances. Isabella does cost a lot more on a monthly basis than the normal kitty, and perhaps the first owner simply couldn’t commit to that additional cost for the next 10-15 years. The first owner did bring her back in for euth (or surrender) rather than dumping her on the street, and so I can’t say she acted irresponsibly.
And heck, I have Izzy now, so we’re all good 