Some health problems are ressessive traits that may be "Hidden" undectiable by health screening, only to appear when breed to another "carrier".(We trust people don't breed dogs with know problems) I wound't use that male on other bitch from those lines. I wouldn't breed the siblings back to those lines, I wouldn't bredd this stud on his future prodegey. Another point to concider have any other litters from this stud resulted in genetic health ptoblems?