Concurrent ANNPE and vertebral T-cell lymphoma in a dog: A case report.

Acute non-compressive nucleus pulposus extrusion (ANNPE) is a recognised cause of peracute spinal cord injury in dogs, involving sudden extrusion of non-degenerated nucleus pulposus with minimal compression. While often linked to vigorous activity, its triggers remain unclear. This case describes an 8-year-old neutered male poodle cross dog who developed peracute non-ambulatory paraparesis while running to retrieve a ball. Neurological examination was consistent with a T3-L3 myelopathy. Magnetic resonance imaging (MRI) revealed disc space narrowing with intramedullary T2W hyperintensity at T13-L1 consistent with ANNPE and a T13 vertebral body lesion that was hyperintense in T1W/STIR and contrast-enhancing, later confirmed as T-cell lymphoma by surgical biopsy. The dog demonstrated rapid clinical improvement, with motor function recovery by day 6 and becoming ambulatory with mild ataxia by week 3. This case highlights the importance of considering underlying vertebral pathology in dogs with presumed ANNPE and emphasises that vertebral lesions detected on MRI may have clinical relevance and should not be overlooked.