The purpose of this study was to investigate the homotypical variation in morphologic and anisotropic properties of trabecular bone from paired canine distal femurs. A microcomputed tomography system was used to produce three-dimensional digital reconstructions of the trabecular bone structures. The results showed that the mean bilateral differences in all bone morphology variables were less than 5%. Differences in measures of degree of anisotropy were also less than 5% between matched sites from left and right sides. In general, the bilateral difference in angle of orientation was less than 15 degrees. These data are valuable for calculating the appropriate sample size to use in experiments using the contralateral canine femur as a control. The results and general approach of the study may have significance for the future use of other contralateral trabecular bone sites as controls.