I feel that they are very important before breeding. Different breeds have different weaknesses......know what to look for in your particular breed. If hips could be a problem, then both parents should be OFA certified, if eyes are a problem, they should be CERF certified. Golden Retrievers breeders are also doing heart checks now. If a breeder doesn't know what you're talking about....run the other way ! Every breed reference talks of the weakness of that particular breed. Good luck !