Please try not to worry too much. I know it's easier said than done. My Starr had a UTI that was caught before he was neutered and then later on when he was having severe diarrhea the vet did an ultrasound and found out that he had a kidney infection. With antibiotics they both cleared up right away. I hope that the same will happen with Timmy.

I always thought that bloodwork was done to make sure that animals will be fine when they give them anesthesia.