A case compression of the spinal cord in a horse by a tumor located in the vertebra is described. A 10-year-old- gelding was euthanized after being found recumbent with hind limb paresis of unknown duration. At necropsy an hemangiosarcoma was detected in the vertebral body of T3. The tumoral mass invaded upwards through the bone tissue of the vertebral body into the vertebral canal, compressing the spinal cord and causing Wallerian degeneration at T1-3 levels of the cord.