Occurrence: Worldwide.
Species affected: All.
Age affected: All.
Causes: Mycoplasma gallisepticumM. synoviaeM. buteonisM. meleagridisM. iners, or Infectious bronchitis virus (IBV) and/or E. coli, and/or Newcastle disease virus and/or Infectious laryngotracheitis (ILT). Spread through egg and contact with infected litter, feed or water. Aerosaol spread also occurs. Severe ND, IBV or ILT reactions may occur after vaccination, especially if given by spray to chicks previously infected with mycoplasma or E. coli.
Effects: Signs include cough, tail bobbing when breathing, emaciation, rales, sneezes, open mouthed breathing, poor growth, decreased feed consumption, lowered egg production and poor shell quality.