To check health clearances on ANY purebred dog, and we strongly suggest you do this with any breed or line you are looking at, go to the Orthopedic Foundation for Animals which is a data base on health clearances for pure bred dogs.
Type in the kennel name you are interested (IE HayTee’s) in or the dogs registered name (IE HayTee’s Unexpected Journey) to do a search. This search will also let you view family members for a more thorough health history. On a Newfoundland for example we would like to see a minimum of heart, hips, elbows and possibly cystinuria clearances. Each breed has different health issues, so if you are looking at a Flat Coated Retriever you need to know what they should be genetically testing for to see if the breeders are really clearing their dogs.
It is nice to be sure a breeder is really doing what they say they are. A pedigree does not make a pure bred dog good; it only means that you bred a Lab to a Lab, period. It is health clearances, carefully thought out breedings and the desire to improve the breed with each breeding that gives a pure bred dog a good start.
Even with all the testing in the world there is no guarantee of freedom from health issues, but we can hopefully minimize known risks.