Nerd bird had HORRIBLE feather coloring and a few deformed flights that never would grow in right. He had white and yellow feathers in places when I first got him with his brother Ferd in 78. Ferd was always fat and healthy and Nerd was always skinny and sickly looking. I found some feather health vitamins and started giving it to him and he slowly molted out all the bad feathers and they never came back. His brother never had any bad feathers and always seemed quite healthy till he suddenly got very sick and died by the end of the day
Nerd and I mourned and bonded with each other and he was my best friends for 31 skinny years.
Once I found out about PBFD I always wondered if he may have had it but once we finally took him to the vet many years later for another issue they never said anything about it and all his tests almost always came back fine. My Other Maxi pionus since have never shown signs of it so maybe if he did have it he overcame it himself and went on to have a happy, though skinny, life with a few deformed and missing flights on his left wing