Association of Mycoplasma synoviae with respiratory disease of broilers.

Serological and cultural investigation of broilers with respiratory disease implicated Mycoplasma synoviae infection in the syndrome which was characterised by variable mortality up to 20% at 6-8 weeks of age in association with Escherichia coli septicaemia. Preliminary experimental studies using specific-pathogen-free birds confirmed that the Mycoplasma synoviae concerned was of the respiratory type, first described in the USA as causing a rapidly spreading, persistent upper respiratory tract infection associated with production losses and in some flocks condemnations due to air sacculitis.