Occurrence: Worldwide.
Species affected: Turkeys.
Age affected: Mainly breeders, poults and young can also become affected.
Causes: Mycoplasma meleagridisM. iners. Spread by mating via semen; transovarian route to progeny; and laterally among poults by aerosol.
Effects: Signs include high embryonic mortality, stunted growth, air sacculitis and lameness. Hock joint swelling, deformation of cervical vertebrae and feather deformities may occur.