Efforts in the US to control Mycoplasma gallisepticum (Mg) began in the 1960’s, in response to high condemnations from air sacculitis after the initiation of USDA post mortem inspections. Later M. synoviae (Ms) and M. meleagridis (Mm) were added to the program. Since then, significant progress has been made in controlling Mycoplasma infections in turkey and chicken breeding stocks.