Wikipedia dfines the risks of inbreeding as: “Inbreeding results in homozygosity, which can increase the chances of offspring being affected by recessive or deleterious traits. This generally leads to a decreased biological fitness of a population (called inbreeding depression) which is its ability to survive and reproduce. An individual who inherits such deleterious traits is referred to as inbred. The avoidance of expression of such deleterious recessive alleles caused by inbreeding, via inbreeding avoidance mechanisms, is the main selective reason for outcrossing.”
What is inbreeding and linebreeding? Inbreeding is the mating of close relatives. Matings between parents and immediate offspring as well as matings between full brothers and sisters is considered first degree inbreeding. Of course, we do not accept inbreeding in humans because of the extreme physical and mental health issues that could develop in the children, even if we aren’t discussing morality. Why do we so blindly overlook the risks when it comes to our dogs? Truly it makes no sense.
Second degree inbreeding involves mating between grandparents and grand-offspring, half siblings, uncles, aunts, nephews and nieces, and double first cousins. This type of breeding is referred to as linebreeding. A simple innocuous word, but linebreeding has the same negative potential found in first-degree inbreeding. After some reflection and research, I don’t believe that we can choose the lesser of two evils, because both practices negatively impact our noble breed. There is no choice–both fail or dogs.
The RSPCA of Austrailia has a strong position on inbreeding and line breeding:
“Given the overwhelming scientific evidence, RSPCA Austrailia’s position is that both first degree (e.g. father to daughter) and second degree matings (e.g. grandfather to granddaughter) should be banned and as a general rule, matings should be arranged between parents that are as unrelated as possible and are also physically and behaviorally sound. By mating unrelated parents, there is a significant reduction in the risk of the offspring from an inherited disorder.”
Profesor David Balding, the corresponding author of the research from the Division of Epidemiology, public health and primary care at Imperial College London, said: “The idea that inbreeding causes health problems in particular dog breeds is not a new one, but we believe ours is the first scientific study to explore this issue and analyze the extent of inbreeding in a systematic way, across many breeds. We hope that following our work, dog breeders will make it a high priority to increase the genetic diversity within different breeds. Otherwise, we will see growing numbers of dogs born with serious genetically inherited health problems.”
Here are a few of the genetic diseases commonly found in German Shepherds today:
A wonderful article in Showsight-The Dog Magazine written by Sandra Murray, What Every Breeder Should Know About MHC, (June 4, 2016) discusses one of the know causes of canine immune suppression that is showing up in inbred dogs. MHC is an acronym for Major Histocompatibility Complex. I won’t go into the details of how these genes work, because it is laid out clearly in the article. Sandra Murray states: “Across the wide range of scientific studies on the subject of immune diseases in dogs, the data all point to an alarming rise in autoimmune and immune-mediated (abnormal activity of the body’s immune system) disease conditions. This is the “dark Side” of the MHC genes. When the MHC lacks the variability in gene combinations to retain the vigor necessary to fight off antigens, a dog’s health suffers. Add to that the possible doubling up of harmful mutations in linebred dogs and the chances exist for inheriting MHC genes that can actually cause dangerous or even deadly genetic conditions.”
Degenerative Myelopathy (DM) is a progressive neurological condition that affects the spinal cord of dogs. It is often compared to human MS. The disease begins with a breakdown of the cells in the spinal cord responsible for sending and receiving signals form the brain. The disease begins in the hind legs causing paralysis and progressively moves up the spine. Dogs that have two copies of the defective gene usually develop the disease.
Most people don’t even know about the the new kid on the block. The Multi Drug Resistant gene mutation (MDR1). The MDR1 gene protects the brain by blocking toxins form entering the brain. When the MDR gene is mutated it no longer functions as it should and it may allow harmful chemicals to enter the brain. When the chemicals have access to the brain neurological conditions, seizures and death may occur. We had firsthand experience with this gene mutation. A stud dog we imported arrived covered in ticks. We do not have ticks on our property, so we immediately took the dog to the vet. We do not use chemicals on our breeding dogs, this was our first exception. The vet removed the ticks and applied Frontline to the dog. Within twenty-four hours, our new guy developed neurological problems. We rushed him to the vet, but he had a massive seizure and died before anything could be done for him. Needless to say, we now test our breeding dogs for this mutation–among others.
Genetic testing alone will not allow us to cull our missteps. Genetic testing is revealing for some prominent disorders; but limited in some very important areas.
Impaired Immune Function, inbred dogs can be born with a low functioning immune system. Low immune function may lead to the myriad of immune disorders that plague modern dogs. They are too may to list, but they run the gamut form susceptibility to cancer all the way to autoimmune diseases, skin allergies and skin disorders. In German Shepherds, it can also present as chronic diarrhea. Some breeders are now stating on their health guarantees that chronic diarrhea is normal in German Shepherds. This is not true! We do not have a single dog in our breeding pool that suffers from chronic diarrhea. And we would never breed a dog with that condition now matter how many hours of training we had invested in the dog.
Psychiatric Disorders, mental disorders do not always show up in puppy-hood. Many conditions only become visible during adolescence. Many strict inbreeding kennels will cull (kill) puppies with deformities and mental aberrations if they can spot them. But some may slip through and arrive in someone’s living room. Many caring owners may spend thousands of dollars on trainers hoping to reach their dog with no luck. This then places the burden of euthanasia on the new owner.
The Dog DNA Team recently discovered a gene for Canine Compulsive Disorder (CCD), which is the canine version of OCD in humans. Limiting the gene pool is putting mental health issues front and center for purebred dogs.
Aggression, there may be a connection between inbreeding and aggression. This includes fear aggression and dominance aggression.
A Decrease in Your Dog’s IQ, Dogs that are inbred can be significantly less intelligent than ones that come from a wider genetic pool. Training outcomes and a basic understanding of how to fit into human society may be compromised in these dogs.
The majority of German Shepherds today are but a mere reflection of the dogs I knew thirty years ago. Some of the stories that people relate to me are heartbreaking: Shepherds dying of immune disorders while still very young, behavior problems that cannot be resolved even with the best science-based training methods, dogs living with chronic intractable itching to describe but a few. These dogs were not from puppy mills or backyard breeders. Many breeders selling very expensive dogs have completely dropped their guarantees, including German and Czech breeders. Importing is no longer a fail-safe transaction. Many breeders are offering very limited guarantees. Instead of dropping a guarantee, breeders should be asking themselves “why” so many of their dogs were activating their guarantee. By asking “why” we can find resolutions to our problems as opposed to the other option–burying our heads in the sand while clinging to an antiquated practice. The science is there, breeding practices need to be changed–buyers and our noble German Shepherds should be protected first and foremost.
Why do we continue an unconscionable breeding practice that causes so much pain for owners and dogs alike–and it is scientifically proven not to work? Linebreeding may work to replicate show ring conformation or to stamp a certain “look of the dog” to a kennel but it has proven a failure at reliably producing intelligence–and mental and physical health. Why are we so blind to our failure? Why do we strive to produce clones instead of mentally and physically sound dogs?
At Tre’Good German Shepherds, we strive to outcross all of our dogs. But, because the gene pool has been greatly reduced we, at this time, are finding it very difficult to source an excellent temperament dog with a 20% COI or less. Unfortunately COI’s of 50% to 75% are common in dogs we test. We are working hard to find outcrosses and are striving to keep COI’s as low as possible at this time in German Shepherd history.
We are also using Embark for a deeper look into our dog’s COI’s. Hardimans can tell us about the past five generations but Embark can go deep into the chromosomes and pull out distant generational inbreeding. We now work with Embark’s Matchmaker program to find suitable geneticly clean dogs ( inheited genes for diseases specific to German Shepherds) and COI matches for our breeding program. We hope in the future all breeders will register with Embark’s matchmaker program so we, as breeders, can work together to create genetic diversity in future generations of German Shepherds,