One of my dogs has off white teeth (no plaque)His teeth were not too good when i got him but since he has been on the part/raw they have improved a great deal (nearly two years now)I do occassionally brush his teeth but they never seem to whiten up like my other dogs.I was just wondering if he is lacking some supplement or vitamin?

Perhaps thats just the colour of his teeth?  Some people have white teeth, some have ivory coloured and some have naturally yellowish teeth and every variation in between :)