Occurrence: Worldwide.
Species affected: All.
Age affected: All.
Causes: Mycoplasma gallisepticum, M. synoviae, M. buteonis, M. meleagridis, M. 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.
Mycoplasma complicated chronic respiratory disease (CRD)
All species of bird of all ages are susceptible to chronic Mycoplasma infection. A number of different agents are involved in the aetiology of this disease. These include M. synoviae (MS) or M. gallisepticum (MG) in chickens, M. meleagridis (MM) and M. iowae (MI) in turkeys. M. synoviae (MS) is usually less pathogenic. Synergistic effects with E. coli and/or NDV and/or IBV vaccine viruses may occur. ILT can also be involved.