Because my puppy-mill rescued sammy has grade 4+ luxating patellas, i am becoming somewhat knowledgeable about them
(can you imagine how many puppies he has helped create at that mill with his bad genes???) As far as breeding, I'll stay out of it! But just so you know, even if his get worse, it's not always painful for the dog. though I do know sammy is lucky, his luxating patellas cause him no pain, and will not (hopefully ever) need surgery because of that.