Radiographic vertebral heart scale and vertebral left atrial size in healthy dogs.

OBJECTIVE: To establish reference values for the vertebral heart scale (VHS) and vertebral left atrial size (VLAS) in clinically healthy dogs and to evaluate their relationship with echocardiographic left atrial measurements. MATERIAL AND METHODS: Forty clinically healthy dogs of various breeds, sexes, and age groups (28 males and 12 females; 26 small, 8 medium, and 6 large breeds) were examined using right lateral and dorsoventral thoracic radiography. VHS and VLAS were measured according to standardized protocols. Echocardiographic assessment included measurement of the left atrium (LA), aortic root (Ao), and calculation of the LA/Ao ratio. Dogs with cardiovascular abnormalities were excluded. Statistical analyses were performed to compare measurements across sex, age, and body size, and to evaluate correlations among VHS, VLAS, and LA/Ao. RESULTS: The mean VHS, VLAS, and LA/Ao values were 9.86, 1.32, and 1.17, respectively. No significant differences were identified between sex, age groups, or breed size categories. No correlations were found between VHS and VLAS, VHS and LA/Ao, or VLAS and LA/Ao. CONCLUSION: VHS and VLAS values in clinically healthy dogs fall within previously reported normal ranges and are not significantly influenced by demographic variables. CLINICAL RELEVANCE: VHS and VLAS can be used as stable and independent radiographic indices for cardiac size assessment in dogs, particularly when echocardiography is unavailable. However, they should be interpreted alongside clinical findings and echocardiography when possible.