Dog stomach on one side is turning almost black and it seems her skin is very dry and flaky?

Dog Question: My dog eats our cat food and we have noticed over the winter that her stomach on one side is turning almost black and it seems her skin is very dry and flaky.  We first thought it was dry skin from the winter.  Could the cat food be making her sick?  She seems to act normal accept for chewing and licking herself.  Thanks in advance

Hi Todd

I don't think the cat food is making her sick.  Skin dicolorization happens in some breeds of dogs. 

Some breeds also see a seasonal change in their skin color.

Skin can also turn dark due to constant irritation lick licking and scratching.

I would check your dog over for fleas and possible allergies.  This might account for both the scratching and the skin color change.