I took her from my boyfriend's courtyard when she was about 4 months because her brother passed and I wanted to save her because she was sick at that time. I kept her in my apartment. I couldn't spay her sooner because she was sick, she wasn't vaccinated, she was also skinny even if she ate a lot, and it took some time until we could spay her.
She was smaller than a normal cat at that age and I think she was born with other problems, because her sister, 5 months older than her, developed very well.
So I took her to this vet from the beginning, he knew her history, that she wasn't 100% ok, but he never questioned if it would be ok to spay her or at least take some tests before, to see if she has something wrong. After I spayed her, she gradually started to eat less, lose weight, she didn't play anymore. I took her to the same vet, he took her blood to do some tests, but it was too much blood taken for her little, weak body and it made it worse. The results were very bad so I took her to another vet, because at this point I didn't trust that vet anymore.
I took her to a clinique for animals, so they kept her on an I.V. to stabilize her, but she already was in a very bad condition. Her red blood cells were dying so we made a blood transfusion from another cat to buy some time. They couldn't take any more blood tests because she was so weak. They managed to test for Fiv/Felv, hepatic and renal disease but the results were negative. So they really didn't know exactly what was the cause. They think it was an autoimmune disease that was triggered by the sterilization, they said it happens very rare and no one would have thought this would happen.
She had two days when she was a little better, she ate and she played a little, but then she became lethargic again.
She died because her heart was too weak and she couldn't take it anymore. They said she survived very long in her condition and they didn't see anyone like her. She was a fighter!
So..it was very unfortunate but some things could have happened to prevent this, that no one thought of. And I blame myself for not knowing better.