I am sorry to hear that, but it's great news that it's an operable shunt. My baby's liver condition is inoperable and has to be maintained with special diet, lactulose, and supplements for the liver. Are you allowed to pick the vet that does the surgery? If so, I would definitely consider going to University of Tennessee...Dr. Karen Tobias is one of the best liver shunt vet in the nation. Did your vet prescribe a special diet for your baby? If not, you need to ask that they put your baby on Hill's L/D or Royal Canin Hepatic LS 14...Also, you should ask for lactulose and denosyl, especially if you're not going to be doing the surgery right away. But honestly, the surgery needs to be done as soon as possible. The longer you wait, the more damaged the liver gets.
Also, I highly recommend that you join the liver shunt/mvd group on yahoo groups. The people on that group are extremely knowledgable about liver conditions and will help with any advice at all. Also their files section is very informative.
http://pets.groups.yahoo.com/group/L...d_MVD_Support/