Hi - I just saw your thread about. your horse, MFM and treatments. I may be going through this with mine, and I wondered how she continued to do?
After the biopsy and diagnosis, I tried to manage her with diet, but gave up after not being successful. I ended up turning her out for about 6 months and eventually ended up putting her to sleep - we had to evacuate for Hurricane Irma and the trailer ride would have been too much for her. This was in 2017 and I haven’t followed it much since. Dr Valberg May have made more headway on managing it, so don’t get discouraged by my experience
Did you do the muscle biopsy?