My Shih Tzu has colored botches on her skin

Question
I have an 8 month old shih tzu who has developed what looks like birth marks on her tummy. It started about 2 months ago with a few spots on her tummy. When I asked the vet about it I was told that dogs sometimes get this and that it wasn't anything to worry about. However, I've noticed more spots and on her tummy and one is quite large. When I was giving her a bath I've noticed these pots also on her hind legs. They are about 1" - 2" in size and the large one on her tummy is about 5". She now has a lot of these and I'm wondering if this is normal? They are all on her skin and not her fur. I've had other dogs and have never had this happen to my other dogs. I should also mention that she is a sensitive dog and is allergic to certain foods which we avoid giving her. The spots are not red or inflammed ~ more like a birth mark. They discoloration is only on her skin and not her fur. Can someone please tell me if this is normal? Sorry for the long question & thank you to anyone who answers.

Answer
She is a bit young for what some of us call "liver spots" (like in people... dogs get those, too), or lentigines. I have seen something similar on a dog's belly that were black and could be scratched off with a fingernail over time. They eventually disappeared.

Since your vet has had a chance to examine them and said there is nothing to worry about, then don't!

http://www.drjwv.com/faq/?view=46&name=Pigment%20Changes