Ann,
I'm so sorry you and Wylie are going through this
I know from experience that the whole Cushings diagnosis and treatments and what ifs are sooo frustrating. It is very complicated getting the diagnosis if that is what it is.
I did learn that a LOT of vets go right into the cushings probability when the dog presents with the heavy peeing/drinking or sublte hair loss. I didn't get through this whole thread (hard to read to much at once right now old age, lol) but I hope that he has had full and complete blood panels done to rule out kidney/liver and or possible diabetes. I am assuming you went through all that already.
As for his Hypothyroid I do know that getting the replacement dose correct is not an exact science and it may take awhile for that to get his thyroid back to normal.
Just want to send big hugs and well wishes for Wylie XXOO
