I would think that the treatment for MG would be the same as with humans. In most cases MG can be controlled enough for there to be some quality of life.
I have always thought that MG was a Chronic Autoimmune disorder that takes years to become a real issue. Until I was finally Diagnosed with Brachial Plexopathy The doctors first thought I had MG. MG in dogs may be completely different that in humans. Your friend's Dog, Jesse, will be in my thoughts and prayers.