The mean vertebral heart size (VHS) was established for Yorkshire Terrier dogs. Thirty clinically normal dogs with mean weight of 2.42±0.64kg and ages varying from one to six years of age, were studied. The animals were submitted to right lateral, ventrodorsal and dorsoventral thoracic radiographs. The Buchanan e Bücheler method was applied to the cardiac silhouette and thoracic depth and width. The VHS was 9.9±0.6 vertebrae on lateral, 10.1±0.6 on ventrodorsal and 10.0±0.6 on dorsoventral radiographs. There was no difference among these values. Five animals (16.7%) presented VHS values exceeding 10.5, the value suggested as upper limit for most breeds in lateral view. However, 95% of the animals in this study provide VHS values below the upper limit, and this should be equal to 11 vertebrae. The VHS values had significant correlation with body weight on lateral and VD radiographs. The mean depth:width ratio was 0.75±0.06. There was no correlation among VHS and depth:width ratios.
dog; thoracic radiography; cardiac silhouette; VHS
