Comparative Assessment of the Vertebral Left Atrial Size in Healthy Adult Dogs

Vertebral left atrial size can be used as a radiographic tool to evaluate left atrial size in dogs. Vertebral left atrial size has been studied in dogs; however, few studies have been conducted on breed-specific differences in healthy dogs. To study the median vertebral left atrial size differences by breed and to investigate the association between age, sex, body condition score, thoracic depth-to-width ratio, and vertebral left atrial size. A total of 220 dogs of the following breeds: Maltese (n = 73), Beagle (n = 30), Poodle (n = 41), Shih-tzu (n = 44), and Mongrel (n = 32) were reviewed retrospectively. Sex, body weight, age, and body condition score of each dog were collected. Thoracic radiography was conducted for dorsoventral and right/left lateral views in all dogs to measure the vertebral heart score, vertebral left atrial size, and thoracic depth-to-width ratio. No significant differences in the median vertebral left atrial size were found among the breeds. There were no effects of sex, age, body condition score, and thoracic depth-to-width ratio on vertebral left atrial size. There was a significant positive correlation between the vertebral heart score and vertebral left atrial size. Breed, age, sex, and chest conformation did not correlate with vertebral left atrial size.