岡山県北部地方に於ける牛のPiroplasmaの調査

We investigated on the invasion of bovine piroplasmosis in Kamisaibara village, the northern part of Okayama prefecture, where about 600 of Japanese breed black cattle were pastured on. As the result of the blood examinations on 285 cattle it was found that the disease prevailed heavily in these areas as shown in tables; namely the numbers of cattle which were detected the minor piroplasma (which seemed to be Thieleria mutans) in thire red blood cells came up to as much as 97.9 per cent, and those associated with the major piroplasma (which was morphologically similar to Babesia bigemina,) were 6.0 per cent. (Table I. & II.) A tendency was shown that the younger the cattle, the more severely was infected with this disease. (Table III.) Being almost of the cattle, in spite of infection with numerous piroplasms, survived without any manifestation such as "Texas fever'", the bad influences of this disease to cattle have never been recognized, but to leave out the condition is to be regarded as highly dangerous for profitable livestock production in this district.