Molson....again (BlackLabbie)

Actually, it's not generally abnormal at all. It's called hyperpigmentation, where the skin in certain affected areas becomes blackened. Gaci's entire vulva is pure black....it startles people who don't understand, but it's just dark skin - it was caused by her long-term tucked vulva issues. Between licking, surgery, etc, it's not pretty by any means, but it's there and not worrisome. The very center of her anus is also black from licking...that was a stress response to the vulva issues she has ongoing.......It doesn't generally go away once it's there, although sometimes some of it will.

It's what it sounds like to me, but always go with your vet as long as you are comfortable with their advice. If the vet says it's not a worry, then it probably isn't.

Ohhhh ok, I definitely never had this happen before so it did startle me! He was licking/chewing/rubbing that area for a long time.

That's probably what you are seeing then. I know, when I first experienced it with Gaci, I was startled as well. But it turned out to be nothing serious.

Kim's absolutely right -- it happens to ANY skin that has been distressed for a while.

This happened to Tessy's skin in areas where she can't even touch it (back of her neck).  She has a really bad staph infection and the vet shaved the area to the skin to treat it.  Once the infection was cured the skin turned dark.  Other areas that weren't shaved but were still infected did not change color as much.

Johnny & Tessy