Just wanted to add to everyone's excellent comments, that my mare was symptomatic and diagnosed when she was 12. She has been on pergolide since then, and I am hoping that by catching and treating it early, we can slow the progress of the disease (she's now 16). She did not have as high a test result as your gelding nor were her symptoms as severe, but I had no hesitation upon starting her treatment. Please, please don't waste his precious time chasing magic bullets that don't work. Pergolide is the only thing that will control his ACTH output, and diet and exercise are the only things that will control his IR. All that you need to do is change some of your management practices (yeah, I know, sometimes that is not as easy as it sounds!). We've all been where you are now, and we have your back in this.
And a big thank you for getting your case history done--that is super helpful.
Maxine and Indy (PPID) and Dangles (PPID)
Canberra, Australia 2010