Early Detection of Enzootic Bovine Leukosis through Measurement of Serum Thymidine Kinase Activity

Abstract

Thymidine kinase is an enzyme related to DNA synthesis. Recently, serum thymidine kinase (STK) activity has been reported as a useful marker of bovine leukosis. In an effort to achieve earlier detection of enzootic bovine leukosis (EBL), we measured STK activity in cows at a farm tainted by bovine leukemia virus (BLV). We found that a Holstein cow aged 10 years and 9 months without any clinical symptoms showed higher STK activity, and the cow was diagnosed as having EBL. Evaluation of STK activity in a herd contaminated with BLV is clinically useful for early detection of EBL.