Abortion, still birth, premature birth and mortality of cross bred dairy cattle (Jersey × Tharparkar/Red Sindhi) were noticed in the organized dairy farm of National Dairy Research Institute, Eastern Regional Station, Kalyani, Nadia, situated in hot and humid climatic area nearer to the river Ganges of West Bengal, India. The history of the farm revealed newly introduction of pure bred dairy cattle and outbreak of FMD during mid March to mid April, affected about 34% cross bred cows. During investigation, intermittent rise of temperature (104°F -108°F), anorexia, rapid respiration, progressive deterioration of health of animals and loss of milk production were also noticed. On the basis of past history, twenty suspected animals were taken for disease investigation. Repeated visit of the farm and repeated examinations of blood smears were done to observe any haemoprotozoan infections. Twenty to thirty percent of those suspected animals were found positive for Brucella antibodies by STAT, plate agglutination test and MRT. After a massive screening of blood smears, during the visit of third time, ultimately one animal (Identification number JT614) was found positive for the presence of Trypanosoma evansi infections in Giemsa stained blood smears. The infected and all suspected animals were successfully treated with single injection of a mixture of quinapyramine sulphate and chloride @ 7.4 mg/kg body weight subcutaneously. As a prophylactic measure, a mixture of quinapyramine sulphate and chloride @ 7.4 mg/kg body weight subcutaneously were also administered to all suspected animals prevented further occurrence of the disease in this dairy farm. It can be concluded that the iAfection with T. evansi in this farm has happened in a condition of intercurrent diseases with environmental stresses.