@3KillerBs any of advice on how to improve ventilation here?
I don't know anything about the medical treatment of chickens, but here is my article on ventilation to show what you should be looking for in the way of airflow: https://www.backyardchickens.com/articles/repecka-illustrates-coop-ventilation.77659/
The most important place to have ventilation is the very top of the coop. If you can ventilate both the top and bottom of the roof slope that would create good airflow under the roof to carry away moisture and ammonia without risking drafts on the roosts.
Since you seem to have some decent roof overhangs it might be as simple as using a sawzall to take out a few inches of wood siding in the appropriate places and replace that with hardware cloth.

