In continuing this subject from a breeders perspective I have to say we have a different view of things than science or certainly someone who is not a breeder. First we have to understand a little about how a breed is created and that by its very nature it is ALL inbreeding and line breeding in the end just because the gene pool is closed.
Back when Herr Dobermann started on his search to create his vision of the Dobermann with very specific traits to provide him the protection he was seeking he had to survey and have some understanding of each dog introduced into the gene pool. With each breed he had specific traits, looks, temperament etc that he wanted to combine and bring into one gene pool. He was not interested increating a "designer" dog that could not reproduce or carry on.
The dogs he selected all had certain things that were good and all had some health issues that they brought to the mix. It is important to remember that back then "the health nut craze" had not infiltrated the world. People accepted as a fact of life - both life and death so I am fairly certain he was not concerned with how long each breed used lived to - He was focused and dedicated to his single mindness in his creation.
Once he achieved the results he wanted - temperament, drive, coat, head, size, he then had to breed them back to each other til they reached a point that they bred "TRUE" to his vision - in other words every dog came out looking like his Dobermann and none ever looked like a throw back to the shepherd, rotties etc. When this happens there are certain things that become SET in the gene pool and are going to be there for life. No matter how much you try to breed away from it there are just too many combinations of genes that can show up at anytime.
I personally believe that the cardio issue was introduced when Groelier introduced the Great Dane into the gene pool. We know Great Danes suffer from cardio. Does it matter - not at this point because we can't go back and take it out of the gene pool.
Breeders HAVE to believe tha they can work to make things better - if we did not believe this we would throw in the towel. Does not mean we can solve it all but means we can maintain for the most part a healthy gene pool to draw from. There are things that affect it - inBreeding, line breeding, and the popular sire syndrome which can and does create a bottle neck thereby diminishing the majority of the gene pool. BUT in a small closed gene pool there are some things that can't be avoided and all the science in the world will not change the overall picture even thoug we would like to think so.
Look at humans for example - we do not necessarily follow any form of inbreeding as it has been banned and for the most part we don't line breed BUT we do have health issues that are common to man. If you listen only to science then we all must stop bnreeding and this will cure the health issues because the species will disappear.
This is a quote from Frank Grover on the ADPEF.org web site on breeding. I thought it could open up some interesting discussion for those who wish to participate. Science has never created anything unless it was in a test tube. I don't want to live in a test tube.
I think it is important to understand first that inbreeding and line breeding are two totally different strategies and can't be lumped into the same sentence.Inbreeding is the mating of two very close relatives - ex. Father to daughter, mother to son, half brother to half sister. This is used when a new breed is being formed inorder to intensify the specific traits one is wanting to "set" in the lines. With that also comes some hidden faults that can be intensified. Once a line is set pretty much what is the the genetic mix is there to stay. That is why in the beginning you hope that there is a wide variety of dogs used to bring about the product you are looking for and that it reduced the negative as much as possible.
LineBreeding is a tried and proven strategy breeders have used with success for many years. It is the mating of more distant relatives ex: Grandsire to granddaughter, Uncle to niece and its goal is to produce more consistent litters. Back in those days dogs were very prepotent meaning the genes were so strong you could predict what they would be like as adults - Each line back then had very distinct charastertics and breeders bred to what they liked. Often you will hear a judge say a dogs is "very typy" and this is mostly due to line breeding.
If you look at the history of the Doberman's that were imported to America, breeders took these dogs and developed several specific "types" from the mix depending one which dogs they crossed. Back in the early 50's, 60's and even into the 70's we saw dogs that were very distinct in type and by looking at the dogs you could tell which kennel they came from because of the line breeding. This is what we call prepotent.
Linebreeding certainly has its place in the purebred dog world and breeders should know the lines and breed accordingly to produce the best dog possilbe while sidestepping the landmines. We must understand that by the very nature of the purebred dogs there is a certain genetic load that can't be avoided because in the end they all came from the same beginnings.
Each breeder has to determine for themselves how much they want to linebreed and how tightly. In all things consdered every breeder I have every talked with agrees you have to go outside to bring in new blood to keep the line strong and healthy without loosing what you have worked so hard to maintain. This is not new to breeders who have been breeding for a while and understand the whole picture.
The problem is today we have way too many johnny come latelys who have no real knowledge of what breeding is really all about or how it plays out and that to me would include the author of the above article. Scientist are not breeders and neither sicene or genetics in breeding always work out in a nice neat little package that would allow us to label linebreeding as a bad thing especailly if they lump linebreeding and inbreeding in the same catagory.