hmmm....something is not right. It does sound like seizure behavior. Not to scare you, but liver shunt is common with Yorkies, and these behaviors could somehow be liver related, or not....it could be something else, not sure what though...
Have you ever had his Bile Acids Tested (BAT) before? This is a simple blood draw test, depending on your area costs about $40 to $80 - But it is a good base indicator of liver function. Maybe you should arrange to have a BAT with your Vet
