Atypical Sporadic Bovine Leukosis with Astasia in a Holstein Heifer

Abstract

An 8-month-old Holstein heifer presented with difficulty in standing. Bovine leukosis was suspected because of the enlargement of the right mandibular lymph node; however，this could not be confirmed by fine needle aspiration of the lymph node and blood examination. A postmortem examination revealed that neoplastic masses compressed the spinal cord and nerves at the atlas and thoratic vertebra. A histopathological examination revealed the mass to be B-cell lymphoma based on BLA-36 positivity，but antibodies against bovine leukemia virus were not detected. The case was diagnosed as an atypical sporadic type of bovine leukosis.