Get Your Dog Care Questions Answered by Experts
Did the diarrhea have any blood?
Did the vet run any bloodwork?Dr.V
It is really hard to tell you what happened. It was a very fast process and it is hard to tell if it was organ failure or shock. They do have acute vomiting and diarrhea with certain diseases like pancreatitis...but again they don't die that quickly.
I wish I could help you more...but with the information given, I don't have a particular idea as to why you lost your dog.
I am truly sorry for your loss and my prayers are with you and your family.