This is often a very difficult condition to detect so don't be too hard on the owner, dogs can live with a simple shunt for years which may be detected due to blood tests for something entirely different.
Occasionally there are animals with multiple shunts so the surgeon won't know how bad it is until all the tests are done. ie Bile Acid tests, 12 hour starvation and 2 hours after food, then she will need a scan to find out how many shunts there are and even with surgery for a simple single shunt the prognosis may not be good. No-one can be certain how the liver will react to the new blood supply and sometimes the dogs die some weeks later.
Shunts may be closed by placing a constrictor round the shunt and slowly closing it over a period of weeks, this may or may not work. This is far from a simple procedure/operation and there may or may not be a good outcome even after surgery.
I know this is not what any of you want to hear but I am a realist and wanted you to be aware of the risks. I had a pup (beagle) back in the 80's with liver shunt so I tend to keep an eye on latest developments.
