BACKGROUND : Cerebrospinal fluid (CSF) is commonly acquired in dogs with intervertebral disk
herniation (IVDH) and is a common method to assess inflammatory responses following spinal
cord injury (SCI).
OBJECTIVES : The purpose of the study was to describe relationships between cisternal CSF
characteristics, behavioral measures of SCI, T2 weighted (T2W) hyperintensity on magnetic resonance imaging (MRI), and long-term outcome in dogs with IVDH. Diagnostic accuracy of
CSF for differentiating IVDH from other myelopathies was also assessed.
METHODS : The retrospective case series included 727 dogs, 443 with thoracolumbar IVDH, 103
with cervical IVDH, and 181 with other spinal cord diseases. Signalment, initial neurologic
function, ambulatory function at long-term follow-up, T2W MRI, and CSF variables were
recorded for dogs with IVDH. Signalment, etiology, and CSF data were retrieved for dogs with
other myelopathies. Associations between CSF predictors, diagnosis, and outcomes were
RESULTS : CSF total nucleated cell count (TNCC) increased with SCI severity (rho -0.256,
P<.001) in dogs with IVDH, TNCC was significantly higher in the presence of T2W
hyperintensity (P = .001) in dogs with thoracolumbar IVDH, but TNCC, RBC count,
microprotein, and percent neutrophils decreased with increasing injury duration (rho -0.253,
P<.001; rho -0.269, P<.001; rho -0.141, P=.004, and rho -0.356, P <.001, respectively). CSF
characteristics were not accurate for differentiating IVDH from other spinal cord diseases.CONCLUSIONS : In dogs with IVDH, CSF TNCC, RBC count, microprotein, and percent
neutrophils are correlated to clinical aspects of SCI such as injury severity and duration, but
cannot differentiate IVDH from other etiologies.