Question Author
Thanks everyone.
Really, I appreciate your kind words so much.
I know I should just accept that these things happen, and in time I probably will, but I just can't help feeling that I'm having the wool pulled over my eyes. If it was down to FIV, as the vet suggested, surely she would have shown some symptoms before the operation. But she was in perfect health - wormed, frontlined, vaccinated for everything possible, and chipped - she even had a pre-op check the week before and was given a perfect bill of health.
I've had cats all of my life, ever since I was a child, and i've never seen anything like this. If it was a mistake made during the operation I was never going to be told about it anyway - the emergency vet wouldn't give a diagnosis that would make another vet in his practice accountable.
I know that in the long run it doesn't matter now. The fees are not the issue, I would have paid anything to have brought her back to health, it's the frustration of not knowing what actually happened to her and knowing that I'll probably never find out.
Thank you again though, guys. It's really comforting to know that people do actually care.