He was neutered on Thursday. I woke up at 5 to pee and noticed he was breathing really heavy and kind of whining. J and I kept trying to petting him and he kept moving away from us. He started throwing up blood and as we were getting ready to take him to the hospital, he stopped breathing. He was only six months old. It must have had something to do with the surgery, but I still can't imagine what might have happened.
I had a kitten die soon after adopting him from the Humane Society a few years ago and it was traumatic. He had some type of virus that affected his heart.