Hemivertebrae is actually a spinal defect exactly where the vertebrae are abnormally shaped. This defect is usually seen in brachycephalic breeds like Bulldogs and Pugs. The 1st reference on the word "Bulldog" is dated 1631 or 1632 inside of a letter by a person named Preswick Eaton where he writes: https://tysondnkgm.mybuzzblog.com/19423769/a-review-of-bulldog