Liver Shunt and MVD is common in Yorkies and to tell you the truth, "strange behavior" like you are describing is one of the top symptoms of Hepatic Encephalopathy.
I would make an appt. with the Vet for a Bile Acid Serum. It costs $60 to $100 depending on where you live. They will tell you to fast the dog for 12hrs. bring him in and they will draw blood, then they will feed him a little fatty food, and do the next blood draw 2 hrs later. The result will be in a few days, because for a correct BAT, the blood needs to be sent out to the lab for the results
