Bulldogs not only have a high incidence of abnormally formed vertebrae, but are also highly predisposed to a premature degeneration of the intervertebral discs. Hemivertebrae are abnormally formed and are usually found in the posterior thoracic vertebrae. These wedge-shaped vertebrae usually cause an abnormal curve of the spinal column which can compress the spinal cord if vertebral shifting occurs. Many Bulldogs with hemivertebrae never show any problems with them, but if your Bulldog does experience spinal cord compression as a result of a hemivertebrae, surgery may not be successful. Block vertebrae are two adjacent vertebrae that are fused together. Butterfly vertebrae are also found in Bulldogs, but often pose no problems.
Spina bifida is also commonly found in Bulldogs. It occurs when the vertebrae , usually in the sacral region, have an incomplete dorsal arch and absent dorsal spinous process, which just means the the vertebrae itself is abnormally formed, but it only causes problems if the spinal cord or nerves protrude through the defect, resulting in neurological abnormalities.