Natural transmission of bovine leukemia virus in dairy calves by dehorning.

Gouge dehorning was evaluated as a mode of transmitting bovine leukemia virus in Holstein calves at a commercial dairy. Significantly (p less than 0.05) more calves dehorned by the gouge method developed antibodies to bovine leukemia virus, as measured by agar-gel immunodiffusion, three months after dehorning, than calves not dehorned. The field use of a blood-contaminated dehorning device resulted in transmission of bovine leukemia virus.