I just recently found out about this test and was wondering if most breeders do this test or not. It sounds somewhat experimental to me, but if the info it provides is accurate, then it may be well worth the money.
it is a blood test that looks at DNA to see if the dog carries the gene that may cause PRA. At least that is the way I understood it. I'm not sure why its not more well known if it is accurate, or why you can still breed a dog if it is a carrier.