Infectious bronchitis is a highly contagious viral respiratory infection of chickens, however, the virus will also infect the urogenital and gastrointestinal tracts. The clinical signs of infectious bronchitis are non-specific and so laboratory tests are required to confirm a diagnosis. Clinical signs are strongly dependent on the tropism (preferred tissue to infect) of the strain, but commonly include coughing, sneezing and gasping in young birds, loss of appetite and wet litter. Feed intake decreases sharply and growth is retarded. Mortality in young birds can be high (up to 30%), however minimal mortality is experienced in older birds (> 5 weeks old). Less common strains can cause a sharp drop in egg production in layers, and production usually drops to near zero within a few days. Recovery occurs within 3 – 4 weeks, however, some flocks never regain an economical rate of lay. During an outbreak, small, soft-shelled, irregular-shaped eggs are produced.