9 year old Barred Rock is gurgling

[Pabbott]

Noticed after the first humid/hot spell we had a couple months ago one of my old hens, Mary started to make sounds when breathing. There are no other symptoms that I have seen. Eyes not swollen, no bubbles from eyes, no discharge from nose. She is still the first one out of the coop to have breakfast every morning and she still rules the roost. She empties her crop nightly.
I can’t find a vet that will see chickens but I gave her 1cc of antibiotics everyday for one week. There was slight improvement. Any suggestions?

 

[Briosafarm]

As a first step, what antibiotic have you been giving her and how did you administer it?

 

[Pabbott]

As a first step, what antibiotic have you been giving her and how did you administer it?

My cat veterinarian told me to get this from TSC and google for the dose which I did at 1cc which was administered in the breast