Bovine leukosis (lymphosarcoma, leukemia, or lymphoma) is one of the most frequent neoplastic diseases of cattle. Two types of bovine leukosis are recognized on the basis of their epidemiology: enzootic bovine leukosis and sporadic bovine leukosis. The enzootic form, which is caused by bovine leukemia virus (BLV), is the most frequent. The sporadic bovine leukosis, which includes the juvenile, thymic, and cutaneous forms of the disease, is not associated with BLV or any other infectious agents [1].