The cause or etiology is unknown, but fortunately the disease is self - limiting: it follows a progressive pattern and generally the animal recovers with or without treatment to a normal state or one so close that you might not be able to tell it had occurred without cutting the
bones for microscopic examination.
Even if the pet has been de-wormed, you should bring in a stool sample
for microscopic examination since no de-wormer gets every parasite that's possible or it might not have cleared all the worms that it should have.
These procedures essentially involve flushing the upper respiratory tract with sterile fluid and retrieving that
fluid for microscopic examination, to identify infectious bacterial, viral and / or micoplasmal organisms.
Prepare chemical solutions, reagents and
specimens for microscopic examination; perform laboratory tests; analyze and report findings; and investigate atypical results and discrepancies to determine causation.
But in perplexing cases, instilling a fluid into those channels and then collecting
it for microscopic examination (BAL = BALF test) will give your veterinarian data to help confirm the diagnosis.
The technician will then prepare the bird's stool
for microscopic examination.