I know that, sometimes, I sound like a broken record but I can't reinforce enough how VERY important diet is when it comes to proper care of our birds! The wrong diet kills while the right diet heals - it's as simple as that.
This article is, of course, about humans but it can be easily extrapolated to our parrots. Our birds all end up suffering from the same problems: liver, kidneys, cardiovascular. And these can all be cared for with the proper diet.
https://www.washingtonpost.com/health/f ... story.html