Hello! I have a one year old female akita and over the past month her once black mouth has slowly started to turn pink. We keep her mostly inside, we keep her on a gluten free holistic diet, ceramic bowls and no ruff plastic toys. She acts perfectly fine her mouth and nose aren't sensitive at all she is still active and playful and normal acting. We have had her since she was 8 weeks and have never had any health issues at all.