Prevalence of a Septicemia Disease in the Crested Ibis (Nipponia nippon) in China

Abstract

This study investigated six cases of septicemia in young crested ibises (Nipponia nippon). These birds all died with similar clinical signs, including sudden death, anorexia, diarrhea, and lameness. Immediately after death, the birds were necropsied; a blood sample was taken from heart and tissues were sampled from liver, lung, spleen, peritoneal mucus, and feces for bacteriologic examination. Anatomic observation showed that the main findings common to the sick birds were arthrocele, associated with congestion in the femur, tibiotarsus, and ventral side; swelling in the liver; hemorrhagic pericarditis; miliary tubercles in lung; and fibrous tubercles in the synovial capsule of the knee joint with suppurative abscesses. Through bacterial examination, the colonial type of Escherichia coli strain was represented prominently in cultures of the feces, heart blood, liver, lung, spleen, suppurative mucus of the synovial capsule, and peritoneal exudate. These symptoms suggested that the death of a number of endangered crested ibis within a short period was evidence of septicemia. The bacterial inoculation tests were also conducted using domestic pigeon, native chicken, and mice for the presence of and infection with E coli. The study provided indications of the possible role of E. coli strains as bird pathogens and a potential risk in endangered species. Further work is needed to characterize E. coli strains and the toxin production in this bird. This disease occurrence also adds a note of caution to the continued efforts and interest in the reintroduction of the ibis back into its former wild ranges to ensure that formerly captive individuals do not transmit disease to the wild populations of its own or other sympatric species.