The ANKC (Australian National Kennel Control Council) rules stipulate that to receive Pedigree Papers, a puppy must come from parents who have been x-rayed for hip and elbow dysplagia.
The most "talked about" condition in the Labrador Retriever is their hips. X-Rays must taken and professionally scored by an accredited facility. Each hip is scored out of a possible 53 with a number of scientific measurements being taken. The lower the score, the better the degree of "soundness". A score of 0:0 or even 5:5 are near perfect. The individual scores are added together to give a total rating. A 4:4 score would equal a total 8 and be given a rating against Australian and International averages. In Australia, the median score of Labrador Retrievers is total 14. It is obviously a median score because not all Labradors are X-Rayed and nor are all X-Rays submitted for scoring. If all X-rays were submitted for scoring then the "breed average" would likely be 18 - 20.
Elbow Dysplasia is the far more serious hereditary defect affecting Labrador Retrievers. Elbow X-Rays are almost always taken at the same time as hips, however elbows are "scored" very differently. An elbow score of 0:0 is perfect whereas a score of 3:3 would be affected. Each additional point above 0 reflects a millimetre of variation (or gap) in the elbow joint.