My 11 month old puppy just had her first heat and started to develop. She has 10 nipples and they all popped out except one of them is inverted. It is on the 'top' row closest to her face so its sort of the tighter part of her belly since it is over her chest.

She doesn't seem to care about it at all but I can tell it is collecting gross stuff in there and I am not sure how to clean it really without hurting her. Its not a big enough space to irrigate it like you can do with an inverted tail or tail pocket. But it is definately like a nipple sized belly button. A q-tip or something like that is still too big to get in there to clean it. But I can tell just by looking at it that there is black yuck in there.

I have heard of people with inverted nipples before but this is the first time I have seen it on a dog.. lol