Update:
The vet called me with this news: Fitzy's red cell count is up, and there is no longer blood in his stools. They want to do one final blood test to see if it's a liver shunt. They will do it tomorrow, and if it is a liver shunt, they will remove it with surgery. He said that 75% of liver shunts are curable, and the other 25% are usually manageable with a diet. He also said that petland will take care of the bills.
Things seem to be looking up for Fitzgerald, but like you said sympa, I hope they aren't using the vaccine reaction as an excuse not to replace the dog if he ends up dying.
