SASAKI Osamu Akita Pref. Coll. of Agric., Dept. of Anim. Sci., Assoc. Prof., 助教授 (80073972)
OKADA Kosuke Iwate Univ., Dept. of Pathol., Assoc. Prof., 農学部, 助教授 (50002077)
SHUTO Bunei Hokkaido Univ., Dept. of Biochem., Assoc. Prof., 獣医学部, 助教授 (60001533)
OCHIAI Kenji Hokkaido Univ., Dept. of Comp. Pathol., Assis. Prof., 獣医学部, 助手 (80214162)
MAEDE Yoshimitsu Hokkaido Univ., Dept. of Int. Med., Prof., 獣医学部, 教授 (40002084)
We necropsied 121 wild waterfowls including swans and geese during a period from 1989 to 1992. Out of them, subacute lead poisoning due to ingestion of spent lead shots occurred in 19 birds in 1989, 47 individuals in 1990 and 3 ones in 1991. Most of them died at a lake, one of heavily hunted areas, in Hokkaido. Two birds with lead poisoning died at another lakes located in Hokkaido and the main land in Japan. Thus, this survey showed that lead poisoning is spread over in many areas of Japan.
The main gross findings of this condition were bile-stained liver, edematous or gelatinous bone marrow, bile-stained lining with hyperkeratbsis and lead pellets in the-gizzard, and proventricular impaction. Histopathologically, there was lead-hemolytic jaundice of the liver, hemosidlosis in the liver and spleen, and hypoplasia of the bone marrow with increased numbers of polychromatic erythroblasts. Acid-fast intranuclear inclusion bodies were seen in kidneys. The lead concentration of the liver ranged from 5.5 to 44.3 mg/kg wet weight in swans.
Radiographs of both gizzard and proventriculus, necropsy and concentration of blood or tissue lead are available for the diagnosis of this poisoning.
Treatment using CA-EDTA was effective in recovering the birds with lead poisoning, although it was not available for the severely affected cases.