You will find a lot of information about liver shunt here on YT. While it is life-threatening if not treated appropriately ~ it certainly isn't a death sentence if the right treatment is provided.
Not every dog will need surgery. I don't know which test your vet was using so I can't comment on the numbers - there might be others here who can. But it appears that the bile acid testing has been done based on what you posted.
Lucy was diagnosed with mild MVD when she was a puppy, but her problems were mild enough that surgery was not required.
Most people who have dealt with it before are not crazy about the Ultrasound - because you are still probably going to need that scintography anyway.
Research as best you can and make sure you are dealing with knowledgeable professionals. Teaching animal hospitals nearby are often familiar with LS.
Best of luck; keep us posted; and keep your spirits up as well as Nicky's. Don't be overdoing it on the protein like beef, liver, etc.
__________________  Mommy to Lucy, Ringo, and Matthew |