When evaluating a newf at a shelter for rescue if the dog has double dew claws in the rear it is considered a mix with a Great Pry. Newfs typically do not have rear dew claws and definitely not double. If a 'breeder' (and I use the word breeder loosely) breeds newfs with double dew claws they are not purebred.He was given to us. Yes he has the double dew claws on his back paws. I was told that there is a lady about 14 miles from where we live that breeds Newfs and hers also have the double rear dew claws.