Theileria annulata infection in neonatal bovine calves.

On an organized farm in India, 70 out of 79 cows expected to calve within 30 days revealed the presence of Theileria annulata schizonts and/or piroplasms in their peripheral blood. Similarly, 33 out of 59 calves borne to the above cows also exhibited T. annulata schizonts on day less than 1 to day 19 post partum. The cows and calves were free from Hyalomma anatolicum, an established vector of T. annulata, during the course of study in the winter months, when the activity of ticks is reduced to the minimum. The infection appears to have taken place antenatally.