I looked up Mycoplasma Gallisepticum.. they dont have that at all.. They are just sneezing and i can hear the odd girgling in a chest .. eyes are clear and eating good and doing good in the cold.. .. nose are fine.. Just sneezing and the odd chest girgling going on
Which is why it could be bacterial and not viral. I would flock treat the water for 1 week with either L-S 50 soluble powder (lincomycin-spectinomycin) or Tylan soluble powder. Make sure the medicated water the only source of water for 7 days, mixing a fresh solution each day. Follow up with vitamin-electrolyte and probiotic dispersible powder in the waterers for 3 days after that. Make sure there is adequate ventilation in the coop to prevent humidity.