Several Mycoplasma spp. have been isolated from avian hosts; M.gallisepticum (MG), M. iowae, M. meleagridis and M. synoviae are the most important. Each has distinctive epidemiological and pathological characteristics. MG infection is commonly designated as chronic respiratory disease in chickens and infectious sinusitis in turkeys. Infection may also occur in pheasants, chukar partridges, and peafowl.