The cattle industry is suffering economic losses caused by bovine leukemia virus (BLV)
and enzootic bovine leukosis (EBL), the clinical condition associated with BLV infection. This pathogen
spreads easily without detection by farmers and veterinarians due to the lack of obvious clinical
signs. Cattle movement strongly contributes to the inter-farm transmission of BLV. This study
quantified the farm-level risk of BLV introduction using a cattle movement analysis. A generalized
linear mixed model predicting the proportion of BLV-infected cattle was constructed based on
weighted in-degree centrality. Our results suggest a positive association between weighted in-degree
centrality and the estimated number of introduced BLV-infected cattle. Remarkably, the introduction
of approximately six cattle allowed at least one BLV-infected animal to be added to the farm in
the worst-case scenario. These data suggest a high risk of BLV infection on farms with a high number
of cattle being introduced. Our findings indicate the need to strengthen BLV control strategies,
especially along the chain of cattle movement.