Darkening skin

Hi, Meg is five and my first dog, I have noticed recently that her tummy is changing from pink to darker pink and in some areas nearly black is this normal? She isn't itching, has been treated regularly for fleas and seems ok in herself. I should add she is a yellow Labrador retriever but her dad was black.

Ask your vet to check her thyroid levels - TSH, T3 + T4. Hypothyroid dogs can have this - our eldest is hypothyroid and has the darkened skin in places.