It is really very weird. They were both vet checked last month. The only comment at that time was that Bella would need a cleaning fairly soon as she had tartar on her back teeth, but Sophie looked good. When I say their gums are red at the toothline I mean front, side middle and back toothline. I have taken away the Himalayan chews for the time being until I know that isn't the problem. They chew on them alot and seem to love them. I hear them working at them and it sounds like their teeth might break!!