Yes I agree with Crystal.
 
I would do a Protein C test first and then go from there...maybe doing a U/S next, but a U/S will NOT show MVD and it isn't even guarenteed to show a LS, so it may be a waste of money.  The Protein C test is inexpensive and it will guide you more toward MVD or LS. 
Roxy has MVD and we found out when she was about 2.5 or 3 yrs. old.  All her blood work until then was normal.  I had heard some things about other pups from the same breeder, so I went ahead and did a BAT.  Her first BAT was 43 (pre) and 100.9 (post). 
With a diet change (I consulted with a Pet Nutritionist from Cornell) and supplments to aid her liver, I have gotten her BAT to less than 5 (pre) and 61 (post). 
I can tell you more later...I have to leave work now to go home 
 
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