They were too sad to get the results right after she died, but today I got an email from my aunt about Diamond.
"The Vet called today and said that she researched the blood test results, ect and she really thinks Diamond died of a uterine infection. She thinks that it burst and no matter what we did, the results would have been the same. She wouldn't have made it out of surgery. It didn't show up on the x ray because it probably already burst. That poor dog. She never let on that she was in pain."