Sensitivity of dog plaque microorganisms to chlorhexidine during longitudinal studies

Plaque microorganisms, which were either aerobic or facultative, from dogs treated 7 or 42 months thrice daily with 0·2 % chlorhexidine gluconate showed a decreased sensitivity to chlorhexidine when compared with plaque organisms from dogs treated with water. This decrease in sensitivity was not associated with a decrease in efficacy of chlorhexidine against plaque or gingivits.