Anyone familiar with swab testing chickens?

[StinkyAcres]

Most respiratory diseases can have secondary infections. It can be common for testing to show infectious bronchitis and mycoplasma, or coryza. E.coli can also be a complication and may cause air sacculitis. A necropsy when one dies is probably the best testing. Heat inside the coop, dusty conditions, mold, poor air circulation all can increase the probability of respiratory issues. During molting is a common time to see illnesses.

Thanks again. Mold and dustiness are definitely possible. Necropsies are quite expensive here. I haven't had any die with these particular symptoms anyway.