HELP! RESPIRATORY PROBLEM IN CHICKENS

[AntonKecha]

Good Evening !
I have 15 ISA Brown hens and 3 roosters, 1 Leghorn and two non-breeds. Also 3 Emden Geese
This morning when I went to open the birds to go out in the coop yard to graze I noticed that 3 hens are breathing with their mouths open and when they breathe they "snort" they make a sound similar to when we are stuffy and can't breathe through the nose .
I also noticed that they cough and sneeze (not very often).
Knowing about the mycoplasma gallisepticum I checked their eyes and they are clear, not swollen and not closed or moist. They are not lethargic.
The rest of the hens and roosters are fine, except that every afternoon because of the extreme heat they sit in the coop and rest.
What baffles me is that within one night (9:00pm I checked them and closed them yesterday & 9:30am I opened them and noticed the above) all the symptoms appeared.
In the midst of all this, in the area where I live there is no veterinarian for hens and productive animals, so the only partial "diagnosis" I can do is through the internet.

Has anyone experienced anything similar??
Could it really be mycoplasma gallisepticum???
How can I help the hens come back???

Thank you very much
AntonKecha

 

[Eggcessive]

Is it hot where you live, and are any of the hens overweight? Are they holding their wings away from the body when they are breathing? How is the air circulation inside your coop? Dust, mold, or lack of ventilation can cause breathing problems in chickens. Have you heard any sneezing or rattly breathing?

 

[LizGio]

What kind of bedding?

 

[AntonKecha]

Is it hot where you live, and are any of the hens overweight? Are they holding their wings away from the body when they are breathing? How is the air circulation inside your coop? Dust, mold, or lack of ventilation can cause breathing problems in chickens. Have you heard any sneezing or rattly breathing?

Yes, it is hot, during the day many times they kept their wings away from their body. The coop is fully ventilated and has a good temperature all day and night. They sneeze but not very often. I hear rattling in the breath.
They also have the ability to get out of the coop if something bothers them in the yard.