Ok, so I checked them both, nostrils and beak.
The BC Maran was fine though I could still hear her breathing same as yesterday.
The Barnevelder, the one with a foamy eye yesterday, her eye was now a bit red/irritated looking and I could see that there might have been some nasal discharge during the night (though her beak was now dry). Cleaned her with saline and looked in her beak: see picture. Is that plaque also a symptom of the mycoplasma or is it possible some chickens of the flock also have wet fowl pox (so far I only saw dry fowl pox on the others, but I haven't rechecked all their throats recently).
I was reading an older thread with the same symptoms about breathing and foamy eyes, and turns out it was e-coli: you think it possible here, or am I just grasping at straws?
The only vet where I live who see chickens says they won't be able to see any before 3-4 weeks out. I was thinking of sending a test to my State vet but that will probably take days before we get a result (for example, they apparently have a pre-registration process that can take a couple before I can even send a sample). I am warry of blindly treating with antibiotics, but should I go ahead and treat with Oxytetracycline? Or maybe with whichever antibiotics is broader spectrum, in case there's still any doubt about the cause herew? while registering with the state vet and sending the sample. Or would it just make it worse?