Comparing the Hearts of German Shepherd and Mongrel Dogs Using Statistical Shape Analysis

The aim of this study was to conduct a statistical shape analysis of the heart of dogs and to compare this data between German Shepherd and Mongrel dogs. An effective way to examine these shapes is to record the locations of certain points on the object. In this study, 10 hearts were collected from each breed. EDMA and TPS techniques were used to examine genus-based changes in the shape of the heart. The shape deformations were expressed using expansion and compression grids. There was no statistically significant difference with respect to the general shape of the heart between the genera. However, there were local shape differences between the genera in some of the inter-landmark distances: 6% of the inter-landmark distances were greater in German Shepherd dogs, and 11% were greater in Mongrels. There are no heart shape differences between genera, although significant differences were found between the upper part of the left ventricle and the lower part of the right ventricle. The upper part of the left ventricle in Mongrels showed more enlargement than in German Shepherds. The lower part of the right ventricle in Mongrels had more enlargement than in German Shepherds; however, the middle part of the right ventricle of German Shepherds had more enlargement than in Mongrels. Although there were some local significant shape differences between the upper part of the left ventricle and the lower part of the right ventricle, however, there were no general heart shape differences between German Shepherd and Mongrel dogs.