Is this a liver shunt?

Hello Dr. Marie,

Murphy is 16 months old. For the first 6 months of her life, she seemed quite normal apart from being a little lazy for a puppy so young. She had bloodwork taken when spayed at 6 months old and nothing was abnormal.

She has infrequent episodes, four in total so far, where she seems to show signs of drunkenness. It starts with her being lethargic all day, she won't eat, her head will start to bob and her eyes aren't focused. It looks like a mild seizure almost. The episodes last for about 4 or 5 hours, then she vomits what looks to be partially digested kibble, then returns to her happy self and goes to her dish looking for food.

After the most recent episode two months ago, we have been through many tests. We tested for Addison's and she didn't have it. Her bloodwork is still normal, except for elevated lymphocytes. She did a bile acids test, her fasted result was 58.6 and her post-meal result was 23. Our vet thinks and has thought this entire time that its likely a liver shunt and recommended an abdominal ultrasound at AltaVista Animal hospital. From what I've read, her post-meal result should have been higher if she had a liver shunt. The ultrasound is $700, we've already spent $1400 on tests to this point. My partner and I have one income while I'm at school and we don't know what to do anymore.

Murphy is happy and healthy looking probably 80-85% of the time right now. Except for the 4 episodes of drunkenness, the only other concern is that she has some lazy days where she doesn't want food and sleeps most of day, maybe once every other week. But she has always been a low energy dog.

My partner and I were thinking that we would change Murphy's diet and monitor her closely to see if this causes a change. I'm wondering what you would suggest. Our vet has led me to feel that this is an urgent situation for Murphy, and that if we wait on the ultrasound, her condition might worsen. I don't want to do anything to jeopardize Murph's health, but we are running out of money fast and not finding any solutions. Even if we did the ultrasound and they found a shunt that was a good case for surgical correction, we would really struggle with the $3000-$4700 they quoted us for the procedure.