I've been giving my cats greenies as treats but I'm not sure if they've helped or not. Starr needed a cleaning in Dec.2006 because his gums were red and inflamed and his breath was also stinky and he rarely ate wet food. He had bad gingivitus and he's not even 2 years old yet. He'll be 2 on March 22nd. Since then I've been adding liquid oral care to their water. It's supposed to help prevent bad breath, gingivitus, and plaque from building up. So far Starr's gums look great.