Who knows? Shepherd of some type? Lab? Boxer? Dachshund? Without registration papers, a dog is just a mutt. I have two, and the majority of people on here also own mutts of indiscernible breed make up.
Looks like a shepherd mix? Looks nothing like a 'pit bull'. (Which is not a breed to begin with) but like Allison said, without knowing the ancestry of the dog, it's just a mutt. No telling what it is.