Could be Aspergillosis, a fungal infection that effects the respiratory tract, if it is, it would need to be treated with anti fungal medication.
A brief outline of what it is.
Aspergillosis disease is caused by the fungus Aspergillus, and its spores are what cause respiratory problems in birds.
The fungal spores can be present in contaminated food, water, nest boxes, incubators, other nesting material, and unventilated areas.
However, birds can also catch the infection from the environment.
Fungal infection is common in birds with vitamin A deficiency, malnutrition, stre