Diagnostic and Prognostic Value of Serum Neurofilament Light Chain in Canine Spinal Cord Diseases

This study evaluated serum neurofilament light chain (NfL) as a biomarker for spinal cord diseases in dogs, including 46 healthy dogs and 76 with conditions, such as intervertebral disc herniation (IVDH), syringomyelia (SM), fibrocartilaginous embolism (FCE), and acute non-compressive nucleus pulposus extrusion (ANNPE). There was a significant difference in serum NfL levels between healthy dogs (12.55 pg/mL) and those with spinal cord diseases (91.10 pg/mL; <i>p</i> < 0.0001). The NfL level in dogs with SM (50.7 pg/mL) was significantly lower than that in dogs with IVDH (99.3 pg/mL; <i>p</i> = 0.012) and those with other diseases, including FCE and ANNPE (241.0 pg/mL; <i>p</i> = 0.002). The area under the curve for differentiating between dogs with spinal cord diseases and healthy dogs was 0.91, with an optimal NfL cutoff value of 30.31 pg/mL (sensitivity of 80.68%; specificity of 91.30%). For dogs with IVDH treated solely with medication, the serum NfL levels in the Poor and Static group (180.0 pg/mL) were significantly higher than those in the Partial and Good group (81.30 pg/mL) (<i>p</i> = 0.03). Serum NfL is a promising biomarker for neuroaxonal injury, aiding in differentiating SM from other spinal cord diseases and evaluating treatment response.