Turning sickness in a cross bred cow naturally infected with Theileria annulata.

Bovine tropical theileriosis (BTT) has been since long recognized as a persistent major constraint on genetic improvement programme of native cattle breeds under "Operation Flood". The disease accounts for high mortality in dairy cattle especially calves. A cross bred cow (Rathi × Holestein), aged 3 years and weighing ~300 kg, owned by a person from weaker sections of the society, initially suffered from ruminal hypotonocity, severe dyspnoea, frothy discharge, lacrymation, cessation of defaecation, anorexia besides, icterus, mild form of anaemia and moderately elevated temperature etc., for the past 48 h. The cow suddenly developed pre mortal fall in temperature and neurological signs suggestive of posterior paresis. Ante mortem laboratory investigations revealed Koch Blue Bodies in the lymphocytes and Theileria annulata meronts in the erythrocytes. The cerebral form of BTT in the instant case was differentiated and discussed with other diseases causing analogous neurological signs.