Is this Microvascular Dysplasia

My dog is a 9 month old pomeranian.  He had an episode where he was over-tired and his was bobbing.  He slept for a couple hours and was back to himself again.  He had another episode a week later with a new symptom, he was dizzy like he was drunk.  I thought he got into something.  There are ton of mushrooms that he likes to get in his mouth and everyone is contantly laying down pesticide and fertilizer around here.  I went to the emergency room and they wanted to do a $350 CBC, Chem, Bile Acid and blood ammonnia test.  His pupils weren't pin-spotted or dialated.  His symptoms were pointing away from toxicity.  I probably should have done it at the time but opted out.  We got home and after 2 hours after the episode started he was back to his old engergetic self again.  On Tuesday I had the CBC, Chem, and bile acid test done.  The vet said his CBC and Chemistry is literally text book perfect.  However, the bile acid test is showing liver disfunction.  His fasting bile acid test was 17 and following eating was up to 47.  The lab is reporting normal results for fasting no greater than 10 and after eating no greater than 20 (I don't really know what these numbers mean).  My vet is still contemplating but she is pretty much ruling out liver shunts becuase the post feeding bile acid test was not high enough.  I guess the next step is a protein C test and then an ultra-sound.  I really don't have money for an ultra-sound.  I can't find a staight answer on the prognosis of microvascular displasia.  I guess it varies case to case.  My dog is super actice and super smart.  He doesn't have any gastrointestinal issues.  He seems to have developed just fine so far.  Does anyone what else to test or look for.  My vet doesn't want to jump and put him on a low protein diet and/or medication until she has the correct diagnosis.  The problem is the lab, my vet and I are stumped at the moment.  The bile acid numbers are stuck in between any conclusive diagnosis.