Squeaky hen with respiratory infection? Antibiotics haven't helped

[pepe le grise]

Hi, have trawled through the forums and it seems there's a lot of things could be causing this!
My hen is about 7 months old, not laying. Has had a squeaky sneeze which developed into more of a cough(?)
She gasps when excited, and in warm weather. Otherwise acting fine, eating/drinking/running around as normal.
It looks like she has swollen sinuses from what I have seen online.
Has been going on for 6 weeks or so now. Tried ACV, garlic, wormed, no change.
A week ago it got a bit worse, so send a video to the vet, who prescribed 6-day course of antibiotics.
I finished this yesterday and haven't seen an improvement.

Any suggestions?? I'm planning to take her to a bird specialist vet later this week if still no change.

Thanks!

 

[nuthatched]

What antibiotics where tried? What is the coop litter? Any ash, DE, mold?

 

[pepe le grise]

wood shavings, cleaned weekly. Baytril 2.5% for 6 days