I applaud breeders who, should a dog be dysplastic , have removed that dog from the gene pool. The dog may appear to the eye "fit as a fiddle". That is why x-rays reveal what the eye cannot see.
I have done this. It is heart wrenching to watch as your plans and future "disappear" but that is part of the commitment of breeding for a better future.
I also agree with breeders who decide to breed a dog between the ages of 1 - 2 when they have such a stellar pedigree of "passing" or "clear" hips, when they do the breeding in a knowledgeable way. They will breed this individual to a dog who has his/her hip clearances or the dog is from a pedigree of clear testing. I have done this as well.
Long time breeders, many who have been in this breed for decades with great success, know when it is worth the risk. They have years of first hand knowledge on their side to take that risk.
I have a young adult bitch who does not have any hip clearances in her pedigree and she will never be bred unless she is OFA certified. She turns 2 in March and will be x-rayed. From there I will plan her future. She is not a dog I will take a risk on.
If your dog is a "borderline", or "questionable", and you are working with a knowledgeable veterinarian, follow his/her advice about redoing the x-ray. Yes, they can be redone if the pass/fail is close. Sometimes they actually will pass the next time and you may be wonderfully surprised.
I know for a fact that only the Lord is perfect.
If your dog is definitely not going to pass… please do the right thing.
We may not have the perfect method but, as responsible breeders, we must use the tools given to us. Whichever method of hip certification that is used, I know for a fact that the person/people evaluating the x-rays have the training and experience that far outweighs any lay breeder who themselves is not a veterinarian or in the fields of medicine.
Rome was not built in a day.