Bloody vomit

[Amystevens77]

My shar-pei was really sick vomiting blood. I brought her to the emergency vet hosp and while I was holding her pure red blood pored out of her rectum. They did testing and everything was fine except her white blood cell count. It was 1 for every ten squares or something like that. Very very low. She was cold on her mouth and paws do to shock. In the end I had her put to sleep but I need to know or have an opinion on what it might have been, if I did the right thing. She was lethargic and dehydrated, still in critical condition for hours. Any ideas? The vet said it could have been leukemia but I am obsessing and wondering if I could have saved her.