My Roxy's first BAT was pre: 43 and post: 100.9
We did a U/S ~ which didn't show a shunt.
I have since changed her diet to a low quality protein diet, with added supplements (Hepatosupport and Vetri DMG), along with some other goodies.
She is now 5 years old. We have done about 7 BATs - the pre has come down to below normal, but her post number stays in the 60 to 85 range.
She shows NO "crazy" symptoms. We are treating her as if she has MVD.
I didn't go the biopsy route because she was already spayed, and I didn't want to put her through an intense liver biopsy surgery, when the life maintenance of diet and supplements were going to be the same regardless. I just didn't need a "confirmation of MVD" and I was preety sure she just didn't have a single liver shunt.
You really need to discuss with your specialist, and please voice your concerns to the specialist, and ask for honest advice on this little baby