The purpose of this study was to determine the suitability for measurement of oral bacterial counts (OBC) in dogs using a new device that operates on the principle of dielectrophoretic impedance. Using this device, bacterial counts were successfully measured in swabs collected from the mouths of 5 non-anesthetized beagles. We tried to take samplings from 6 sites in each dog’s mouth and stable counts obtained at an interval of 2 weeks showed no significant difference in any of the 6 sites over time. However, since the counts showed significant differences depending upon the number of times the swab was rubbed on the sampling site, and the time from feeding affects oral bacterial counts, special attention is needed on these 2 issues. The new device allows rapid measurement of oral bacterial counts in dogs under appropriate conditions. The simplicity of this method may make it useful in studies on agents affecting OBC in dogs.