Education is the primary role of the rec.pets.dogs. A breeder who knows enough to carefully evaluate the parent dogs, and their pedigree, for sound genetic health and temperament understands that the information simply cannot be omitted from an advertisement. Thus if the information is missing it is likely because it does not exist. A good advertisement shows that the breeder used care and thought in the breeding decision. Nope, the owner who went to the trouble of keeping it in top condition would certainly advertise that fact.
Similar principles apply to advertising puppies.
That the parents were checked for genetic disease before breeding will always appear in the advertisement. I've never seen a circumstance in which the breeder did do the testing but neglected to mention it in the advertisement. Because anyone who knows enough to do the testing knows exactly how important that information is to the knowledgeable buyer. Breeding without knowledge is a major reason for the continuing problems with genetic disease. The people in the newsgroups have heard some very tragic stories.