Abstract
Clinicopathological responses of calves to experimental infection with a field isolate of Theileria sergenti were studied in two splenectomised and one non-splenectomised calves.
In the two splenectomised calves, the maximum parasitemia level reached 26.3% and 31.3%. Severe anaemia, and hepatic and renal dysfunction were caused by parasite multiplication in the blood. One of them died at the acute anaemic phase. In the dead calf, a decrease in mean corpuscular hemoglobin concentration and a marked increase in leucocyte count were observed. Moreover, a large increase in GOT, GPT and LDH levels and a large decrease in blood glucose level were observed.
In the non-splenectomised calf, the maximum parasitemia level reached 12.6%, and anaemia appeared, just as in the splenectomised calves. No blood chemical changes were observed at the anaemic phase, but the GOT and LDH levels increased at the schizogonic phase.
These results indicated that this field isolate of T. sergenti was proliferated in not only splenectomised calf but also non-splenectomised calf and caused severe anaemia and hepatic and renal dysfunction by multiplication.
It was confirmed that the dead calf developed severe hepatic dysfunction, leucocytosis and macrocytic, hypochromic anaemia. In addition, hepatic dysfunction was present at not only the acute anaemic phase but also the schizogonic phase.
