What does it mean that my dog has seven claws on its leg?

Most dogs have five forelimbs and four hind limbs (so does my dog)

There are six, very few ~

Seven? I am ignorant ~ I have never seen or heard of it, and I am curious (* _ _ *)

Many pictures are atavism (the ancestor wolf of dogs).

This has nothing to do with health, purebred and intelligence.

It has more toes than other dogs.