ANATOMICAL SURVEY OF THE CATS LUMBOSACRAL SPINAL-CORD

The precise termination of the cat's spinal cord is unknown. To effect ively diagnose and treat lesions in this region a proper anatomical un derstanding is required. The lumbosacral region of 42 normal cats was dissected. Several measurements were made and compared to Xerographs o f the region. The conus medullaris of the spinal cord terminated over the vertebral body of S1 in 83.3% of the 42 cats studied, and over L7 and S2 in 7.1% and 9.5%, respectively. Spinal nerve L6 originated from the spinal cord predominantly over the vertebral body of L5 or at the L4/L5 articulation. Spinal nerves L7 and S1 originated over vertebra L5 or at the L5/L6 junction. Spinal nerves S2 and S3 originated over v ertebral body L6 or the L5/L6 junction. There was no significant corre lation between age, weight, breed, spinal canal diameter, or the L1-L7 distance and the location of the conus medullaris; however, a reliabl e predictive parameter for its termination was found to be 94.4% of th e length from the cranial aspect of the vertebral arch of C1 to the en d of S3 (SE +/- 0.87%, P = 0.01). Also, the distance from the cranial aspect of the vertebral arch of L1 to the conus medullaris termination was 35.2% of the C1-S3 vertebral length (SE +/- 0.97%, P = 0.01).