<div style="text-align:justify">Background: Theileriosis is a haemoprotozoan illness that poses severe economic loss to dairy farmers due to its negative impact on mortality and productivity, especially in tropical and subtropical areas of the world. 
 
Methods:&nbsp;The present study was conducted for a period of one year (June 2020 to July 2021) during which 55 blood samples of cattle showing clinical signs suggestive of theileriosis were examined and quantified by using multiplex real time PCR for Theileria orientalis and Theileria annulata using Taq-Man probe. 
 
Result: Prevalence of theileriosis in three Theileria-endemic districts of Odisha due to Theileria annulata and Theileria orientalis were 26.11 per cent (11/42) and 57.14 per cent (24/42), respectively. Mixed infection were reported in 16.6 percent (7/42) cases. Parasite load for T. annulata in clinically affected cases ranged from 2.85&times;103 to 1.51&times;105 parasites per ml of blood while for T. orientalis,&nbsp;it ranged from 1.94&times;104&nbsp;to 5.88&times;105&nbsp;parasites per ml of blood. Ten cattle positive for T. orientalis were administered two doses of buparvaquone (Butalex) @2.5 mg/kg b.w. at an interval of 48 hours after which degree of parasitemia were quantified ten days post treatment. The parasitic load in blood ten days post treatment decreased significantly from 4.04&times;104 to 2.21&times;102 per ml of blood.</div>

RT PCR Assay to Determine Efficacy of Buparvaquone in Reducing Degree of Parasitemia of Theileria orientalis