In other dog breeding programs line breeding to reinforce characteristics is the norm. I have seen very little line breeding in the retriever world. Is there a reason for not doing this, or is it just done by default?
Line breeding is the cause of so many genetic conditions we are seeing. People now are doing better at not doing it, but if you look at pedigrees chances are there will be some common relitive. I raise cattle and its the same way, thats so bad that the general rule is grandchildren are safe to breed back to grandparent.
I talked to a guy that used to work at one of the local dairy farms. He said it wasn't unusual for the sire to be the dam's sire and grandsire and sometimes the same bull would be more frequently than that. They were still using frozen of the particular bull he was talking about for several years after he died. Quite scary when you think about it.
Oh it is horrible. The industry focuses so much on certain traits that when a bull ( most of the time) has them, he gets used tirelessly. Then after inbreeding (which is all line breeding is) so many time the genetic flaws come to the surface. Most of the genetic defects we are seeing are recessive traits, inbreeding is the fastest way to cause recessive traits to be expressed.