Hemivertebrae are the most common vertebral body malformations in screw-tailed brachycephalic breeds. Although hemivertebrae are incidental findings in many instances, they can also cause spinal cord dysfunction, particularly in pugs. This study compared different hemivertebra subtypes among these breeds. Hemivertebrae were classified into subtypes, and the associated spinal curvature was quantified using Cobb angle measurements. Certain breeds were found to be more associated with certain hemivertebra subtypes. In addition, the ventral hypoplasia subtype was found to be associated with higher Cobb angles and a higher likelihood of kyphosis. The ventral hypoplasia subtype was the most common subtype in pugs, which was the only breed found to have this subtype. Although the clinical significance of these findings is unknown, the authors suggest these findings may explain why pugs appear to be more predisposed to development of clinical signs attributed to hemivertebrae as compared with other screw-tailed brachycephalic breeds.