Observation on the schizont stage of an unidentified Theileria sp. in experimentally infected sheep.

The schizont stage of an unidentified Theileria sp. infective for small ruminants was observed. Intact sheep were infected with adult Haemaphysalis qinghaiensis collected from fields where ovine theileriosis was prevalent. When the infested sheep developed theileriosis, tissue and organ smears were prepared. Theileria schizonts were demonstrated in liver, spleen, lung, kidney, lymph node and peripheral blood. Most of the schizonts were found outside the host cells, which was probably a smear artifact. This study adds our knowledge that lung and kidney can be parasitized by schizonts of Theileria sp.