What symptoms is your pup having that made you feel something was wrong?
Don't ever let someone tell you that you are neurotic because you care about your pup! Try to relax ... I know that is easier said than done, but unless your pup is really really sick, this is something that can wait.
Here is a great brochure about liver shunts and MVD. It tells all about the tests to diagnose these things.
http://www.vet.utk.edu/clinical/sacs...2013-04-10.pdf