I would think having her teeth cleaned would help.....?
Even if they don't look 'real bad', it could still be part of the problem.... have you checked on denta sticks and such? Greenies? I don't use those, I like getting nylabones myself, which could work....if she chews on them that is.
I think greenies/dental chews is the closest thing your are going to get to listerine.....
You made me LOL with this!God I love this dog but morning kisses will definitely open your eyeballs.