Thanks so much for the update, Bill, even though I was hoping for some good news for a change.
Perhaps it's worth a try to change Toots diet??? I 100% agree with Shelly about feeding as much fresh, organic, raw food as possible. Yes, Harrison's is supposed to be the best...here, I tell you a little story. It's not bird related, but I think it's still worth telling:
I had a Bernese Mountain Dogs with more health problems than you can imagine. He was on one of the most expensive dog foods on the market, yet he was at the vet CONSTANTLY. He had numerous sebaceous cysts, allergies, inverted hocks, and severe arthritis. I finally had enough. I took him off the meds for his arthritis, off the meds for his allergies, off pain killers, and started preparing his food myself. Mostly raw meat and other foods. A Berners life expectancy is 8, and we never thought he'd even make it to that. Well, he lived to be 11. No, his arthritis didn't vanish, his hocks weren't repaired, but his sebaceous cysts stopped growing, and he truly surprised us all.

(The vet being the MOST surprised)