I posted at K9D... doesn't make sense to me to give Trilostane (suppresses cortisol) and Prednisone (supplements cortisol) at the same time regardless of what's going on with him.
If his PDH has developed into a larger tumor, higher cortisol via prednisone or even a stronger steroid could be helpful and might be able to alleviate his seizures, allowing you to skip the phenobarbitol.
Perhaps TAMU needs a nudge to consult with their neurologist and all sit down together and consider the possibility of a macrotumor as the cause of his various issues.
His diabetes at this point is NOT a reason to give a small dose or no dose of steroids and suppress cortisol. He could need all the steroid/cortisol he can get at the moment to reduce inflammation from a brain tumor that my be the cause of the seizures.
Natalie