Salmonella enterica subsp. enterica serovar Agona infections in commercial pheasant flocks

Infections in pheasant flocks due to Salmonella enterica subsp. enterica serovar Agona occurred in a commercial pheasant farm in 1995 and 2000. S. enterica serovar Agona isolates obtained from the affected birds in both years and an environmental sample from 1998 showed an identical pulsed-field gel electrophoresis pattern, indicating that the farm was continually contaminated with the strain during this period. Nine hundred and seventy-three of 1850 birds (56.2%) died at 4 to 5 days of age in 1995, whereas 80 of 2004 birds (4%) died at 15 to 25 days of age in 2000. Pericarditis were found in the birds in both years although infiltration of heterophils in the lesion was more remarkable in the birds in 2000 than those in 1995, indicating that the S. enterica serovar Agona infection in pheasants in 1995 may have led to the rapid death. These observations suggest that susceptibility of pheasants to S. enterica serovar Agona is age dependent.