Prevalence of hemivertebrae in brachycephalic dog breeds according to radiographs

Abstract

Hemivertebra is a kind of changed vertebra in the spine characterized by uneven vertebral body formation, which can cause curvature of the spine. It is an inherited congenital defect found in both humans and animals. This defect occurs predominantly in brachycephalic breeds, such as French Bulldogs, English Bulldogs, Pugs, and Boston Terriers. The aim of the study was to analyze the prevalence and the degree of development of this pathology in a selected population of French Bulldogs (n = 58), English Bulldogs (n = 9), and Pugs (n = 14). The occurrence of hemivertebrae was evaluated on X-rays performed in lateral and ventral-dorsal projections. Depending on the dog’s size, the voltage ranged between 76 and 54 kV, and the current ranged between 16 and 20 mAs. Hemivertebrae were found in 73% of dogs. The largest number of them were found in French Bulldogs and the fewest in Pugs. In 14% of dogs with confirmed malformation, neurological symptoms occurred. This study indicates that hemivertebrae is a developmental disorder most common in French Bulldogs, and the least frequent in Pugs. However, Pugs, more often than other breeds evaluated here, were diagnosed with hemivertebrae causing neurological disorders. In the thoracic segment of the spine, a hemivertebra usually affects Th5, Th6, Th7, Th9, and Th10. Due to the large prevalence of wedge-shaped vertebrae in brachycephalic breeds, radiographic examination for the presence of this defect is recommended in breeding dogs. Further uncontrolled proliferation of this defect may permanently damage the gene pool of these breeds.