Sir Professor Patrick Bateson pointed out that currently the Accredited Breeder Scheme under the auspices of the KC is worthless. He would not direct the puppy buying public towards it and he says that identifying a good breeder is very difficult under the present structure. 

But he does, thankfully, give us a steer. He cites research here: 

7.32 Indrebø (2008) made some wise remarks about the drawbacks of over-zealous breeding procedures. She pointed out that making too stringent demands in eradication programmes may eradicate the best breeders from the programme instead of diseases from the dogs. Nevertheless, her own recommenda­tions were firm. It is worth restating some of them:

a. If a dog suffers clinically from a disease that is suspected, but not proven, to be inher­ited, the dog should not be bred. If close rela­tives of such a dog are used for breeding, they should be mated to dogs from bloodlines with low or no occurrence of the same disease.

b. Over a five year period no dog should have more offspring than 5% of the total number of puppies registered for that breed.

c. A bitch that is unable to give birth nor­mally should be excluded from fur­ther breeding – irrespective of the breed.

d. A bitch that is unable or unwilling to take care of its newborn puppies should be excluded from further breeding.

e. Dogs that behave atypically for the breed or are un­duly aggressive should be excluded from breeding.

f. Screening for polygenic diseases should only be recommended for diseases and breeds where the disease has a ma­jor impact on the dogs' functional health.

g. Breed specific health issues that cannot be di­agnosed by DNA-tests or screening programs must still be included in a breeding program.