My oranged-winged amazon is loosing her contour feathers in belly til the neck.

by Karen
(Peru)

I wonder what could be wrong with my orange-winged amazon.I purchased her 6 years ago she never had problems,I don't know exactly how old she is but just 3 weeks ago her countour feathers in her belly all the way to her neck and some of her back inside the wings have fallen off.She doesn't have other symptoms besides that she doesn't show other changes.She does get itchy and scrtaches a little.I've taken her to the vet but in my city there are no avian vets.The vet told me she has deficencies.He gave her 3 drops of some liquid to deworm her and to dissolve a pill for the same thing in her water and another liquid thats serves as a vitamin also to dissolve in her water. It has been two weeks since the treatment she was getting somewhat better new blood feathers started appearing but the next day they were all gone she was in the same condition as before.very little countour feather and barely any down feathers.I dont know what to do. Please help me.