Trypanosoma theileri (Laveran, 1902) in cattle in Formosa province: isolation, culture and haematological changes.
During the period 1990-1992, T. theileri was detected by the microhaematocrit technique in 38 of 567 beef cattle in the province of Formosa. Stained smears were made from positive samples for morphological studies. The protozoa were cultured on a biphasic medium using agar as the solid phase and Hank's solution as the liquid phase. Epimastigotes (95%) and spheromastigotes (5%) were observed in the cultures. In a comparative study between the haematocrit and culture methods sensitivities were calculated as 50% and 89%, respectively. Severe lymphocytosis was detected in a group of 6 T. theileri-infected cattle, 16-24 months old. These animals were suffering from stress and a poor nutritional state. A follow-up blood examination after 60 days showed that the lymphocytosis remained high. The host-parasite relationship of T. theileri and its differential diagnosis from other trypanosomes is discussed.