|Unfortunately, there are several websites, such as Gooddog coming up nowadays that are "rating/grading" breeders of every dog breed. It should be noted that they do not have the experience nor knowledge required to do this adequately. Newfoundland dogs are required to have a heart clearance by a cardiologist, not a general practioner, and should have an Advanced Cardiac Clearance consisting of an echocardiogram and auscultation. Gooddog rates a breeder that has hip, elbow, and a practioner heart clearance as excellent, though a practioner is not a cardiologist. Unfortunately, this is an example of the lack of experience and attentiveness required to identify and ensure that breeding dogs are healthy and have all clearances. Websites such as Gooddog, as of now, don't know the requirements of each breed for their clearances. Please do the right thing and go to this page on Orthopedic Foundation for Animals (OFA). On this page, select the breed of dog and the clearances that the breed should have will be listed. Additionally, OFA also provides the link to the official website for each breed in the USA. You may also go to this page on American Kennel Club (AKC) to find the Official Club for each breed, known as the Mother Club. Just a friendly reminder: OFA has been supporting canine health for over 50 years, not trying to help anyone sell a puppy. Please don't be taken by these unscrupulous unethical ratings given out by websites.
Ensure each parents heart has a clearance posted on OFA, by a board certified Cardiologist, accept no less.