Compressive hydrated nucleus pulposus extrusion in a dog

An 8-year-old female neutered Maltese Bichon Frise was presented to a small animal hospital for assessment of acute paraplegia. Diagnostic imaging including plain spinal radiographs and CT angiography was neither suggestive of an intervertebral disc extrusion nor any other abnormalities could be detected. The dog was referred to the emergency service of a specialty hospital for an MRI scan. The MRI showed features of a hydrated nucleus pulposus extrusion (HNPE) at L2-3. Subsequent hemilaminectomy identified a mixture of white gelatinous and partly firm material. Cytology and histology were consistent with a partially degenerated nucleus pulposus. Compressive HNPE of the lumbar spine was diagnosed. The dog was discharged 5 days postoperatively. At the last follow-up conducted by phone interview (2 months postoperatively), the owner reported normal ambulation without any signs of neurologic deficits.