The aim of the research is to determine the differences of biochemical blood parameters in the intact cows and in those infected with the bovine leukemia virus (BLV). The feeding and keeping conditions for the livestock of both the control and experimental groups were similar, provided by the technology of the farm. Studying the blood samples was performed using traditional laboratory diagnostics methods. The results of the study were processed using biometric methods with determining the level of confidence based on the Student’s criterion. Significant differences were found between intact and infected animals in a number of indicators. The differences revealed in the biochemical parameters of the blood in BLV-infected and intact cows may indicate the development of pathological processes in the animals infected with the bovine leukemia virus.