You are of course aware that OptiGen only identified the gene for prcd-PRA in 2005. Many of the dogs on your list were born in the eighties... good Labs but wrong century for the clearances you want!!
Maybe I am missing something, but is there a need to really go too far back regarding PRA? (What else do you use Optigen for??). Your dog is either tested or directly from tested parents....I don't do but one "Clear by Parentage". I honestly don't care of Charway's Ballywillwill has had a PRA test done. My dogs descended from him have had their own test done. That's all you need.
Yes, alot of dogs to old to be tested. But nice dogs. Some other I also would run from for other reasons. Just make sure parents are done or Stud is Optigen Clear.
