VERTEBRAL HEART SIZE RANGES SPECIFIC FOR WHIPPETS

Abstract

To assess the influence of breed, breeding lines, and training on heart size, the vertebral heart size (VHS) was evaluated on left‐to‐right lateral, right‐to‐left lateral, dorsoventral, and ventrodorsal thoracic radiographs from 44 whippets free from cardiac and pulmonary disease. In lateral views, the VHS was 11.0±0.5 vertebrae (mean±SD) on right‐to‐left lateral and 11.3±0.5 vertebrae on left‐to‐right lateral radiographs, being larger than the 9.7±0.5 vertebrae proposed by Buchanan (PPPPP<0.0001). Dogs out of racing pedigree lines had a significantly larger VHS than those out of show pedigree lines, and trained dogs had a significantly larger VHS than nontrained dogs. Because most trained dogs came out of racing pedigree lines, and all nontrained dogs came out of show pedigree lines, however, it is difficult to determine whether the higher VHS for trained dogs is due to genetic influences or training, or both. In conclusion, it is important to take into account the breed and the radiographic view when evaluating heart size in thoracic radiographs of whippets to avoid overinterpretation of cardiac enlargement in these dogs.