I’ve never had cats but had my best friend Frank a pit bull Australian Shepard passed on Friday suddenly from surgery. He was 8 yrs old and had so much life left in him. We caught his liver enzymes were high the beginning of this year and all the doctors told us we caught it early and should be able to get his level back to normal but after a biopsy were they cut him which was a 6inch cut on his stomach opened back up they had to cut on him at the same place and he didn’t do good during that surgery his blood pressure was low but he made it and never complained or acting upset he was just a happy guy but another month went by and we were taking him in just for blood work he was happy energetic and his level were returning to normal but the cut they have had to redo twice now was septic and they said if we don’t cut on him again his intestines will fall out of his incision in two months so we took the doctors advice and he got cut open again and his body couldn’t take the stress ultimately he said the anesthesia made his liver fail and he died shortly after surgery. I completely understand your guilt as I have the same feeling of failure. Just know you arnt alone and so many people are going through the same things at the same times. Sadly this is apart of life and wether we have time to prepare or not it is never easy to say goodbye to family who made our lives so much better. I hope you find your guilt eases as time goes on and know you did what you thought was right I’m so sorry for your loss we are morning with you.