Sorry for your loss of Angel. There is a difference between finding yeast and the specific organism that is avian gastric yeast, did the vet specifically say he found AGY in Sprocket? I have had 3 birds with AGY, the drug of choice and really the only one that has been proven effective against an active infection is Amphotericin B. AGY is a tough thing to deal with, and so is Ampho B, and can be accompanied by other issues as well such as secondary infections. It can be brought under control but it is my understanding that it cannot be completely eradicated. The AGY organism likes to live in the area between the proventriculus and the ventriculus and is not always shed in the droppings so it may not always be found in a fecal exam. I have a bird currently undergoing treatment for AGY and he is not allowed contact with the other birds during the treatment, he is in the same room but is not allowed out of the cage time with the others.