I have found it’s ethical breeders who test their dogs prior to breeding. Ethical breeders seek to better the breed not just to sell puppies. There are several genetic tests out there for purchase which will evaluate your dog’s genes for you.
Where do you start? Embarkvet test or others on the market. They will tell you if your dog has any issues with diseases or anything else genetically passed down from their parents. If you do discover something, the best action to take is, do not breed that dog. If your results are good and you wish to move forward with the breeding process, then you also need to have further tests which are breed specific. There is information on OFA.org regarding tests which need to be done per breed which help others find you as n ethical breeder.
I will share here the links to my dogs embarkvet tests to show you everything that is tested, traits, colors, body type, temperament and more.