My Blue & Gold Macaw is coughing & sometimes congested

by Audrey
(Orange Ca US)

Max is a girl with a boy name

we have alot of dust around due to a remodel, could this be the cause? we took her 3 times to the vet. he prescribed antibiontics all times, one time for a month & it made little difference.
The condition comes & goes, this morning I woke to hear her coughing louder than normal, I don't know what to do
I've had her for 10 years, nefore that I've never had a bird at all-zero experience, the person that had her was going to put her to sleep because they deemed her to be too hostile, I spoke up & took her.
She's extremely tame now, she rides her own horse, she goes on vacation with us, etc, I just don't know that much about their health situations, any help is appreciated