Intervertebral disk disease is most commonly characterized by intervertebral disk herniation (IVDH), which is caused by either disk extrusion or protrusion. Disk extrusion occurs from the complete tearing of the annulus fibrosus with displacement of the nucleus pulposus in the vertebral canal or intervertebral foramen; disk protrusion is caused by partial tearing of the inner layers of the annulus fibrosis with displacement of the nucleus pulposus into the torn region. IVDH diagnosis requires advanced imaging (eg, MRI, CT, myelogram) but can be suggested by radiographs showing suspicious signs (eg, an opacity in the vertebral canal, narrowed articular facet space and/or foramen, narrowed or wedged disk spaces).
Medical vs surgical treatment of IVDH depends on clinical status, financial feasibility, and the degree of changes seen on imaging. Medical management is recommended for cases with spinal pain +/- mild paresis or ataxia. Multimodal therapy involves analgesia, anti-inflammatory, and muscle relaxant therapy. Surgical intervention is usually reserved for patients that have not responded well to medical management or that have more severe clinical signs. Deep pain sensation is the primary predictor for motor function retention: Animals with intact deep pain sensation have an 80% to 90% chance of regaining motor function, whereas animals lacking deep pain sensation only have a 50% chance. Discussing supportive care and husbandry requirements with the owner is essential, especially in severe cases, as inappropriate bladder management can cause significant morbidity.—Isaacs A