Tumors were detected in 670 of 9, 156, 633 slaughtered pigs examined during 1970-1990 at the meat inspection office of Kanagawa Prefecture; 146 lymphomas, 124 nodular hyperplasias of liver or liver cell adenomas, 121 nephroblastomas, 109 malignant melanomas, 69 ovarian hemangiomas and 33 uterine leiomyomas. Lymphomas, malignant melanomas and nephroblastomas were more frequent in the fattening pigs, while nodular hyperplasias of liver or liver cell adenomas, ovarian hemangiomas and uterine leiomyomas in the retired sows. The incidence of nephroblastomas in sows and gilts were about twice more than that of boars and hogs, and higher occurrence rate in the mixed Hampshire breed was suggested. The incidence of malignant melanomas seemed to have decreased with decreased number of colored breed.
View full abstract