Acute bilateral proptosis in a cross bred calf naturally infected with Theileria annulata.

Ever since 1970, Bovine tropical theleriosis has been recognized major constraint to livestock improvement programme in the semi- arid and enzootic areas of Rajasthan. In contrast to other apicomplexan protozoan infections of blood, pathophysiological impact of Theileria annulata has been incriminated to in situ intra-leucocytic development of the pathogen. In continuation with recent manifestations documented on trans-placental T. annulata in a 3 day old cross bred calf and cerebral form of bovine theleriosis "Turning Sickness" in an adult cow, herein an another interesting manifestation of the disease "exophthalmos" incriminated to congenitally acquired T. annulata infection in a cross bred calf, its pathogenesis and impact are being presented and discussed.