Mycoplasma gallisepticum, coryza, laryngotracheitis, bronchitis
My questions is : How do we know which of the 4 diseases our chicken may have when the symptoms are all alike? How does one come to think that it is rather the coryza than the mycopasma. Is the only way to know which diseases is it is to test it in a lab? In all cases should we slaughter our hens to get rid of the disease knowing that they will be lifelong carriers in the 4 diseases?
Outside United States
A lot depends on the age of the infected birds, the speed of spread, and the history of the flock. But the only definitive method is with a post mortem and lab tests.