Morphometric analysis of spinal cord termination in Cavalier King Charles Spaniels

Background There is an association between Chiari malformations, syringomyelia (CMSM) and tethered cord syndrome (TCS) in people, suggesting Cavalier King Charles Spaniels (CKCS) with CMSM could also have TCS. Currently there are no data on the position of the caudal spinal cord structures in CKCS. Objective To describe and compare location of spinal cord termination in CKCS with weight‐matched controls and to examine the relationship between SM and spinal cord termination. Animals Thirty‐nine CKCS and 33 controls with thoracolumbar MRIs; 34 of 39 CKCS also had cervical MRIs. Methods Blinded retrospective study. Spinal cord and dural sac termination were determined from T2‐weighted sagittal and transverse images and half‐Fourier acquisition single‐shot turbo spin echo sequences. Intra‐observer reliability was determined using kappa analysis. Presence of SM was compared with location of spinal cord and dural sac termination. Results Intra‐observer reliability was moderate for identifying spinal cord termination (Kappa = 0.6) and good for dural sac termination (Kappa = 0.8). The spinal cord terminated at lumbar vertebra 6 (L6) in 1, 7 (L7) in 22, and sacrum in 16 CKCS versus 9 at L6, 23 at L7, 1 at sacrum in controls. Spinal cord (P