Previous studies have described paw preference and asymmetry in dog brains. Electrical activity of the dorsal hippocampus also indicated the existence of hippocampal asymmetry in dogs. In the present study, the possible paw and sex-related asymmetries and right-left differences in dog hippocampus were investigated. The hippocampus was dissected and weighed. Each hippocampus was cut into slices by the slicing apparatus placed horizontally on the tissues. The volumetric measurements were performed using the formula modified from the Cavalieri principle. The present study indicated the significant sex and paw differences and no right-left asymmetry in dog hippocampi. The morphological asymmetries in normal subjects might be related to functional hippocampal asymmetries in memory or in cognitive skills. Copyright © 2006 Taylor & Francis Inc.