Can high humidity make hens sick?

[chickenfarmergal]

Our weather all of a sudden is super high humidity and yesterday I noticed some of the hens sound a little "congested" and seem to cough almost. There' no sign of egg bubbles, not noticing any stuff flying out when they cough/shake their head. I've picked up a couple and I'm not seeing any wet beaks. All are still very active and eating. Someone locally said that the high humidity which makes conditions damp can bring on respiratory illness. I have Dengard I can use. I have Tylan 50 that I can use. But can the sudden high humidity cause this type of issue?

 

[Wyorp Rock]

Possible if there's not enough ventilation in housing and there's ammonia build up.

I think I would investigate more before treating for respiratory disease unless you've brought in new birds within the last 30 days.

 

[Goosebaby]

I would say yes, bacterias and fungus thrive in moist warm conditions so it makes sense that humidity would be an issue.
You could try adding oregano oil to their water to boost their immune systems and maybe a drop of poultryRx down the throat.