Cervical spinal nerve and brachial plexus schwannoma in a rabbit (Oryctolagus cuniculus)

Abstract A 4-year-old castrated male lop-eared rabbit (Oryctolagus cuniculus) presented for right thoracic limb weakness of 1 week duration. Radiographs of the limb and adjacent spine were unremarkable. Despite treatment with meloxicam, limb weakness slowly progressed. Four months after initial presentation, neurologic examination revealed monoplegia without loss of pain perception in the right thoracic limb. Computed tomography scans showed multifocal regions of lobular, homogeneously contrast-enhancing tissue within the right ventral vertebral canal. This tissue extended into the right intervertebral foramina at C3-4 and C4-5 and at C5-6 and C6-7. A guarded-to-poor prognosis was given to the owners, who elected palliative care. Treatment with prednisolone and antibiotics resulted in short-term improvement. The rabbit became increasingly weak and passed away 4 weeks following the CT scan. Necropsy identified spinal cord compression due to a mass within the right vertebral canal that exited at C4-5 and continued into the right brachial plexus. The identified mass was morphologically and immunohistochemically consistent with a schwannoma. This case report documents the first clinical description of schwannoma of the spinal roots and brachial plexus in a rabbit.