OBJECTIVE To determine the effects of 2 different, commonly used surfaces with different coefficients of friction on ground reaction forces in normal dogs. METHODS Prospective, observational, single cross-over study. METHODS Dogs (n=10) with no gait abnormalities. METHODS Dogs were acclimated to the force plate and 5 valid trials for each dog and each limb were recorded. Velocity and acceleration were tightly controlled. Each dog was tested on both surfaces sequentially in different sequences. Data analysis was done on peak vertical force, peak impulse, breaking and propulsion peak forces and impulses. Three-way repeated measures analysis of variance was used to separately evaluate the effect of floor type on force plate measures in fore and hind limbs, while controlling for side (left versus right) and experimental replicate. P-values<.05 were considered significant. Mean force and 95% confidence interval for the 6 variables analyzed for all limbs on each surface were calculated. RESULTS There were no significant differences in ground reaction forces between the linoleum and the carpet surface for thoracic or pelvic limbs for all gait variables measured. There were no significant differences between each individual gait trial per dog between the right and left thoracic limbs trials nor differences between the right and left pelvic limb trials. CONCLUSIONS Normal dogs had no change in their ground reaction forces on linoleum and carpet surfaces. CONCLUSIONS Kinetic results from multi-center or comparative trials will not be affected by use of either linoleum or carpet surfaces.