I have recently got a puppy having always rescued older dogs and I now feel like an over anxious mum. My problem is - she is now 12 weeks and up to now had a lovely pink tummy. It is now grey. She seems healthy in every other sense. It just when I had her checked by the vet when I brought her home a pink tummy was one of the things he looked for to show she was a healthy dog. So now I'm worried. Can anyone help?