How about dogs registered with the CKC? Not the Canadian Kennel Club, the Continental Kennel Club. As per their website:

"Dogs over 6 months of age which have no previous Registration history may be registered by providing 2 witness signatures attesting to the purebred status of the dog along with 3 photos (front,left and right) of the dog to confirm it is ‘of proper breed type’ as defined by our current CKC Registration Rules and Regulations.Canine Registration Applications are available in PDF format from our web site."

So it only has to LOOK purebred. When I see anything posted that a dog is CKC registered, I tell people to run the other way!