You're not going to get a definite response, because it's a mutt. No one knows what kind of mix it is unless you know what the parents were. To me, it doesn't look like a 'pit bull' AT ALL. And if your vet told you it had 'pit bull' in it just by looking at it, that's ridiculous. You CANNOT determine a dogs breed based on looks alone. Your dog looks like a shepherd mix of some sort. But like EVERY POST on here so far, we do NOT know, since we know nothing of the heritage of the dog.