Health Carlie's copy

We want to make sure the information we share about breed health is current and correct so this page isn't quite ready yet - please consider it under construction and stay tuned!

The Doberman Heart

An estimated 60% of Dobermans will be diagnosed with Dilated Cardiomyopathy (DCM), which is fatal disease. DCM has an average age of onset of 6-8 years old, but can develop at any age. There is no definitive test to determine if a dog will develop this disease in the future. DCM incidence in a dog's pedigree, along with confirmation that neither parent is already affected, are the only two tools we have to help us minimize the risk of producing puppies that might become affected by this condition. Every ethical breeder should have a recent, clear ECHOCARDIOGRAM and 24 HR HOLTER MONITOR done on their breeding pair. See the different sections below to learn more about DCM, the tests used to screen for it, how genetics play a roll, and how we incorporate this information into our breeding program.

What is DCM?

Most Doberman DCM exhibits as left heart failure. However, about 30% of cases exhibit arrhythmias which can result in sudden death. Early signs of the disease are subtle (gradual exercise intolerance and weight loss) and are very frequently overlooked or attributed to other causes. By the time a Doberman is overtly symptomatic (lethargic, coughing) the disease has already progressed to end stage and life expectancy even with medical intervention is short: days to weeks. However if preclinical signs of DCM are found and supportive medication and monitoring are begun while the disease is still in the occult phase, affected dogs can expect many more months and even years of life before end stage DCM presents.

Tests for DCM

Because DCM can initially present in two different ways, via structural changes to the heart or via arrhythmias, it is important to screen for both. An echocardiogram directly measures heart morphology, and a 24-hour ambulatory electrocardiograph (Holter) checks for the presence of arrhythmias. Because by the time a dog shows overt symptoms, they have already sustained irreversible damage to the heart and their long term prognosis is poor, it is recommended that every Doberman have both screenings done at least yearly starting at the age of two.

DCM Genetics

Studies by Dr. Meurs, a veterinary cardiologist at North Carolina State University, found two potential genetic mutations that were initially believed to be strongly linked to a given dog's risk of developing the disease. Unfortunately, follow up studies have found that these two mutations are not the answer that Dr. Meurs had hoped for. Many dogs with copies of both mutations live well past 10 years old with healthy cardiac check ups up until they pass away due to other causes. Additionally, quite a few dogs who have testing clear for both mutations have gone on the develop and die from the disease. The reality is that DCM is likely due to a very complex interrelation of both cardio-protective and cardio-destructive genetic markers, and that DCM1 (PDK4) and DCM2 (TTN) gene test results do not accurately predict DCM risk at this time. No ethical breeder will call their dogs "cardio clear" based on DCM1/2 gene test results.

(1) Assessment of PDK4 and TTN Gene Variants in 48 Doberman Pinschers with Dilated Cardiomyopathy. Kathryn M. Meurs, DVM, PhD, Joshua Stern, DVM, PhD, Darcy Adin, DVM, Bruce W. Keene, DVM, MS, Theresa C. De Francesco, DVM, and Sandra P. Tou, DVM. Journal of the American Veterinary Medical Association. (November 15, 2020, Vol. 257, No. 10, Pages 1041-1044)
(2) Canine Dilated Cardiomyopathy - Recognition & Clinical Management. Kathryn M. Meurs, DVM, PhD. (2002).Waltham/OSU Symposium

Genetic Diversity

Inbreeding depression is a term describing the negative effects high level of inbreeding can have on a population of animals. One such effect is reduced longevity: a recent study found a direct relationship between increased inbreeding coefficient and decreased lifespan. The Coefficient of Inbreeding (COI) is a measurement assessing inbreeding in an individual. COI ranges from completely diverse/outbred at 0%, to completely inbred at 100%. For reference, in an otherwise diverse population, a sibling-sibling breeding would produce offspring with a genetic COI of 25%, a parent-child breeding would produce an offspring with a genetic COI of 50%. Unfortunately Dobermans are critically inbred on a breed wide level, with an average COI of 40%. Additionally, no registered purebred Doberman in the 3,000+ dogs tested through the Doberman Diversity Project have been found to have a COI lower than 20%.

While it is tempting to see these numbers and simply breed for a lower genetic COI, if dogs from unhealthy pedigrees are utilized, they will still pass their poor genetic health onto their progeny. Lowering genetic COI is only part of the the equation.

How to lower COI Through Breeding

There are two distinct populations in Dobermans where pedigree health and longevity is carefully tracked and considered - American show lines, and European working lines. Through extensive research, we began to appreciate that breeding across these populations, while also keeping a close eye on overall pedigree health and longevity in any potential stud dog, would produce a litter with much lower COIs. This gives the next generation the best chance for long and healthy life. As part of our focus on health, we genetically test every puppy through both Embark (in partnership with the Doberman Diversity Project), and VGL. We were pleased to see that the genetic COI of the puppies in our A litter ranged between 24 - 28%. (This "belongs" in this section as you have it titled, but at the same time it doesn't because it primarily discusses my own breeding choices, as opposed to just being educational. Perhaps it belongs elsewhere? Or maybe each of these groups of drop downs should have a last drop down on how I incorporate
this information into my breeding choices?)

Individual COI vs Breedwide Diversity

Measuring COI & Diversity

Editing Notes:
A section on how we use this information is needed. It is whiplash inducing to stick information about my breeding program at the end of these informational sections.

Note: should the other tests be mentioned?
We need to have a section somewhere that discusses the importance of pedigree research, and how no lines are clear of DCM. maybe include in this section information about dobequest, doberbase, and working dog, as well as a call for more transparency in the COD DOD.

Cut from elsewhere:
We focus our breeding program on lowering the COI of the puppies we produce in order to promote health and longevity, and are thrilled to report that every puppy in our "A" litter tested between 24-28% COI with Embark. Continue reading below for more information.

The Doberman Heart
Every ethical breeder should have a recent, clear ECHOCARDIOGRAM and 24 HR HOLTER MONITOR done on the breeding pair.
This literally cannot be stressed enough. An estimated 60% of Dobermans will die of Dilated Cardiomyopathy (DCM). It has an average age of onset of 6-8 years old.

There is no definitive test to determine if a dog will develop this disease in the future. DCM incidence in a dog's pedigree, along with confirmation that neither parent is already affected, are the only two tools we have to help us minimize the risk of producing puppies that might become affected by this condition. Studies by Dr. Meurs found two potential genetic mutations that were initially believed to be strongly linked to a given dog's risk of developing the disease. Unfortunately, follow up studies have found that these two mutations are not the smoking gun that Dr. Meurs had hoped for.(1) Many dogs with copies of both mutations live well past 10 years old with healthy cardiac check ups up until they pass away due to other causes. Additionally, quite a few dogs who have testing clear for both mutations have gone on the develop and die from the disease. The reality is that DCM is likely due to a very complex interrelation of both cardio-protective and cardio-destructive genetic markers.

Every Doberman has a risk of developing DCM. Early signs of the disease are subtle (gradual exercise intolerance and weight loss) and are very frequently overlooked or attributed to other causes. As noted in 2002 by Dr. Muers (2), "In the majority of cases, DCM is diagnosed when a Doberman pinscher presents with signs of left heart failure. However, about 30% of the dogs develop ventricular tachyarrhythmias and may present for syncope or die of sudden death before ventricular dilation and systolic dysfunction have developed."

Because it can initially present in two different ways, it is important to screen Dobermans with both an echocardiogram, to directly measure heart size and function, and an ambulatory electrocardiography (24 hour holter monitoring), to check for the presence of ventricular premature complexes (VPCs). By the time a dog shows overt symptoms, they have already sustained irreversible damage to the heart and their long term prognosis is poor. It is therefore recommended that every Doberman have both screenings done at least yearly, starting at the age of two.

How Genetic Diversity is Measured
There are two different companies that measure diversity using two different methods. Each method has its strengths and weaknesses.

The Doberman Diversity Project partners with Embark Veterinary. Embark uses a genome wide marker panel that tests over 200,000 SNPs to search for long tracks of homozygous (identical) markers, which indicate inbreeding in given the dog's pedigree. A more detailed explanation about how this is measure to determine a dog's genetic COI can be found here. This is a measure of a dog's diversity within their own genome and is what has been linked to better longevity and health. While a breeder can use tools available through Embark to determine the expected average COI of a potential litter between two dogs, it doesn't directly note the relatively rarity of a given dog's genetics compared to the breed as a whole.

The UC Davis panel looks at STRs from 33 locations that have been established as being strong indicators of how rare a given dog's genetics are compared to other dogs in the population. While the UC Davis panel also considers how genetically inbred the given dog is, in what they call a measure of Internal Relatedness (IR), this is a much more limited measure than what is provided by Embark. The strength of the UC Davis panel is that it directly highlights how common a specific dog's genetics are compared to the rest of the Doberman population. More information about the UC Davis Diversity panel in Dobermans can be found here.

Genetic Diversity's Role in Longevity
On a genetic level Dobermans are critically inbred. As would be intuitive, recent studies have found that high levels of inbreeding decreases longevity substantially. Research through the Doberman Diversity Project has found that the average Doberman has a genetic Coefficient of Inbreeding (COI) of 40%, which is incredibly high! For perspective, in an otherwise healthy and diverse population, a breeding between full siblings would result in progeny that have a COI of approximately 25%, a breeding between parent and child would produce a COI of approximately 50%. Studies are ongoing, but it is possible that sections of the Doberman genome are likely fixed - no registered, purebred Doberman has be found to have a COI lower than approximately 20%

There are two distinct populations in Dobermans where pedigree health and longevity is carefully tracked and considered - American show lines, and European working lines. Through extensive research, we began to appreciate that breeding across these populations, while also keeping a close eye on overall pedigree health and longevity in any potential stud dog, would produce a litter with much lower COIs. This gives the next generation the best chance for long and healthy life. As part of our focus on health, we genetically test every puppy through both Embark (in partnership with the Doberman Diversity Project), and VGL. We were pleased to see that the genetic COI of the puppies in our A litter ranged between 24 - 28%.

In addition to considering the diversity of genetics within a dog's own genome, it is important to appreciate that the Doberman genepool is very limited as a whole. Most well bred Dobermans are genetically very closely related to one of the two distinct genepools mentioned above. There are, however, a few lines found in some lesser known populations that are relatively unique. The health and longevity of these lines are often not as well tracked. We don't yet know if these relatively unique genetics are rare because they are lines that escaped the genetic bottlenecks in the breed's history, or if they are rare because most breeders have selectively bred away from dogs with these genetics because of poor health, temperament, or structure concerns.

We keep breed level diversity in mind in our breeding choices, but it is not a focus of our breeding program because our foundation bitch does not carry such rare genetics.

While it isn't the focus of our own breeding program, we follow with interest and support those who focus on preserving the genetics of the breed as a whole. Because the genepool is so limited in our breed, healthy dogs that have uncommon genetics should be bred to limit further loss of genetic diversity on a breed level.

Other Health Testing

In addition to cardiac health and genetic diversity, it is important for breeders to test for other potential issues in the breeding pair.

This tests include:

OFA or Penn Hip evaluation of hip x-rays:

OFA evaluation of elbow x-rays: While elbow issues aren't common in our breed, it can be a debilitating issue when it occurs. Elbow evaluations are not considered an essential test, but is one that we have done to ensure the soundness of our dogs.

vWD:

OFA Eye Exam:

CHIC Certification:

As part of our commitment to health Piper was CHIC certified before she was bred and we annually retest for any health conditions that can occur over time. When possible we submit these updates to OFA. (OFA only accepts results on some tests from specific labs, which is not always feasible). We believe transparency is an important part of responsible breeding and update all health testing on Piper's Dobquest Profile. We also request that puppy homes keep us appraised about any health issues so that we can have a full picture of the health of our lines.

Breed Health