I too worry about proper medical attention, typical vets do not know crud about chickens and fowl.
I so wish the best for your roo. if he has no improvement I would start your own treatment from all that info, keep an eye on the body condition
@casportpony
How to Provide Emergency and Supportive Care CLICK HERE
Treating Chronic Respiratory Disease (CRD) https://sites.google.com/a/poultrypedia.com/poultrypedia/medicine-chart/baytril-for-birds
I have to look up what generic baytril options are if Kat doesnt help out here...