I'm not a doctor but those numbers point more toward MVD. You need to join the LiverShunt Group on Yahoo. There you will learn what to feed. You need to start with low protein diet. Science Diet ld or Royal Canine HP. Your Vet seems to be following the correct protocal. Scintigraphy would be next. They injectect dye into I think the speen and watch it go thru the Liver.
Portal Scintigraphy in Veterinary Medicine Good luck to you and your baby. I have been thru this with Manolo. He has MVD and liives a full normal life. Just watch what he eats.
And yes right after Manolos scintigraphy he did the biopsy because the scintigraphy came out normal. Then the Biopsy was sent off and that came back MVD. My doctor just did a clear cut biopsy. The Scintigraphy and Biopsy took 20 min.