Dog Has Skin Tag On Lip What Is This On My Dog?

What is this on my dog? - dog has skin tag on lip

Some time ago a dog had a wound in the lip. Because in kindergarten, she searched for a while, to see if the wart was still a puppy, but he says he does not seem quite that it is not necessary to the vet, and he is completely healed, and after two days . He thought it was probably just a skin tag. I say this because it is the first time I heard of something like
Today, while playing with my dog, I noticed something a little rusty on the belly. It is a circle slightly smaller than a penny. There are no other bumps anywhere else. It is far enough in his stomach, about two inches above the vaginal area, a few in the middle of the line of the nipple.
Any idea what might that be? A little afraid that we are puppy warts. isNo one? It's a bit of a strange place for them, they have scratched, I think it could be a bit like exsema (SP). Not at all addressed, as well as a red scab like thing. For me, it's hard to really see, because it is not really in the not always held her back.
To my knowledge, has not been exposed to something unusual.
They do not seem to be bothered (although last night I kissed her belly, but may have been the more toilets)
It is a laboratory at the age of one years