Infectious bronchitis can be caused often by mycoplasma...specifically gallisepticum. It is extremely contagious as the bacteria (it is a bacteria not a virus...tylan is an antibiotic most effective against mycoplasma. Viruses are not effected by antibiotics.) is extremely small and can be carried through nasal passages of humans...it is also extremely common as many wild birds are carriers. I have a lot of experience with dealing with this and while the exposed birds will be carriers for life the symptoms are treatable and, I beliebe, preventable. I was able to deal with a poultry vet through a vet University which has helped. Foest of all doxycycline or tetracycline in water will not trwat the gurgling bird fast enough and neither will tylan soluble. Tylan 50 or 200 will burn the esophagus of a bird if administered orally and will odten cause muscle atrophy if injected intramuscularly.it should be given subcutaneously near folds of the wing and body or leg and body. Tylan 50 at o.5 cc done 2x a day for3 days at most should knock out symptoms. Often even results after the first injection. Typically mycoplasma will have some sneezing with clear discharge as the very fiest symptom after a couple days the gurgle starts and then if untreated the bubble eye will occur. Ince they get to this stage its hard to get under control and they need more injections. Denegard administered as a preventative once a month for a couple days has prevented all 50 of my carrier birds to be asymptomatic for 10 months now.
The key is isolating the first bird to show symptoms and treating it pronto.
Disinfecting the coop is a daunting task with mycoplasma simply because it is literally so small, sticks to everything and is so highly contagious. Infected birds can infect healthy birds so fast that respiratory symptoms can start in less than 5 days. Wash and disinfect feeders and waterers they might have shared at the very least with bleach
Yikes, not sure I can isolate!
We have 2 coops and 28 hens and several in the one coop, that has too much moisture inside, are the ones who gurgle! I have given them more ventilation-which I am aware is the biggest source for the problem to start,...but I don't know I can isolate the sick ones -all exposed now-anyhow good suggestions