Imaging of the vertebral column and medulla spinalis in brachycephalic dogs with computed tomography

Objective: In this thesis study, a comprehensive evaluation and segmental comparison of numerous morphometric parameters of the cervical, thoracic, and lumbar vertebral segments were conducted in small brachycephalic dog breeds (French Bulldog, Pekingese, and Pug) across three anatomical planes (sagittal, transverse, and dorsal). The measurements included vertebral corpus length, vertebral height, dorsal and ventral paraspinal muscle heights, paraspinal muscle height ratio, insertion angle, and the distance to the insertion point, among many other parameters. The resulting data revealed significant findings regarding the structural, functional, and clinical diversity of the vertebral column (columna vertebralis). Material and Methods: The study sample consisted of 23 individuals examined via computed tomography (CT). Measurements were obtained using multiplanar reformat (MPR) techniques and DICOM-based analysis software. Statistical evaluations were performed using SPSS software, and one-way ANOVA with post-hoc tests revealed significant morphometric differences both between segments and across breeds. Results: In the cervical region, a trend of increasing insertion angles and paraspinal muscle dimensions was observed, which is consistent with the region's high degree of flexibility. In the thoracic segments, a progressive morphometric alteration from cranial to caudal was detected, indicating biomechanical relevance for load transmission and postural stability. In the lumbar region, variations in vertebral height and insertion angles appear to reflect structural adaptations to increased regional mobility demands and mechanical loading; such differences may play a significant role in stabilization capacity and range of motion. Breed-specific evaluations revealed that French Bulldogs generally exhibited more developed paraspinal musculature and higher insertion angles, whereas Pekingese and Pug breeds presented with more compact and shorter segmental morphologies. Segmental fluctuations in paraspinal muscle height ratios, insertion angles, and vertebral morphometry may represent potential risk factors for intervertebral disc disease and highlight the importance of individualized approaches in spinal surgery and implant planning. These findings are consistent with previously reported intra- and inter-breed morphological differences in the literature and underscore the necessity of considering such variation in radiological and clinical assessments. Conclusion: In conclusion, this study demonstrates that vertebral morphometry in small dog breeds varies significantly both among vertebral segments and between breeds. The findings emphasize the essential need for precise and individualized planning, particularly in spinal surgical interventions involving brachycephalic breeds.