Did you get him from a breeder, or a rescue? If rescued, there's a pretty good chance it's a mix. If a breeder, it's probably more likely to be purebred (but there's a great difference between BYB dogs and dogs bred to meet a standard by ethical and reputable breeders).
You likely won't be able to tell for sure until the dog is older. With only the photo I would just as easily guess big Lab as Great Dane at this age! I wouldn't worry to much about what random strangers say, unless that random stranger was in fact very familiar with Great Danes.
You likely won't be able to tell for sure until the dog is older. With only the photo I would just as easily guess big Lab as Great Dane at this age! I wouldn't worry to much about what random strangers say, unless that random stranger was in fact very familiar with Great Danes.