DCM and the Doberman Crisis

With all the good and grace that is the Doberman there is a dark shadow; Dilated Cardiomyopathy, DCM.
DCM is a common form of heart disease among all dogs but particularly plagues the Doberman. Nearly 60% of all Doberman will be diagnosed with DCM by the age of 8 years old. There is no way to prevent DCM. It is a very complex disease. There are many factors to DCM, from environmental, hereditary, genetic, nutritional, eugenics, and more. It is a devastating disease, often fatal, and hard to detect early.
https://onlinelibrary.wiley.com/doi/full/10.1111/j.1939-1676.2010.0479.x

The Rise of DCM

Before the 1970's DCM was barely heard of. Since the rise of the Doberman's popularity in the AKC show ring and in the hearts of people globally DCM has been on the rise. One theory, the "Popular Sire Syndrome", believes one or a few select dogs corrupted the once diverse gene pool and sacrificed the breeds health. The thought is one or a few very popular and in demand dogs dominated pedigrees eliminating much of the diversity that was once there. Another theory is inbreeding reduced the diversity. It is thought by selecting only certain traits or from certain popular kennel lines the breed foundation was sacrificed thus causing the decline of health and diversity. Many other theories exist but one thing is certain, the obvious lack of genetic diversity is the reason the Doberman suffers DCM like it does today.

Prevalence of DCM in Doberman Study: https://pubmed.ncbi.nlm.nih.gov/20202106/

Doberman and Genetics

DCM was thought to have a genetic basis but the research is showing genetic mutations alone aren't the cause. The two most common genes researched are DCM1 (aka PDK4) and DCM2. The Doberman Diversity Project states 73% of unaffected Doberman tested in their research had one or both DCM genes and 99% of dogs diagnosed with DCM had one or both genes. Putting it in other words; 7/10 Doberman without clinical DCM carry a DCM gene. 99/100 Doberman who were clinically diagnosed with DCM had at least one DCM gene. Genes alone don't predict DCM. There have been many Doberman to develop DCM and not have the genes, as well as many to have a gene or both and not develop DCM. There is no proven known way to prevent DCM. It is a very complex disease with many factors from environmental, hereditary, genetic, nutritional, to eugenics, and even more. It is a devastating disease and so widespread in the breed there may not be a way to reverse it without drastic measures.

DCM Myths

DCM can be bred out. - Sadly, no. Research fails to provide evidence that selective breeding practices of "DCM free" dogs lessens the rate of DCM affected dogs.
There are DCM free lines. - No, absolutely not! All Doberman are subject to develop DCM. Some lines seem more affected than others and some less, but no line is free from DCM.
European Dobermann don't get DCM. - False! FALSE! The original DCM study used European Dobermann. All Doberman come from the same ancestry, the same roots, the same foundation dogs, and thus have the same risk. http://dobermanpuppyforsale.com/health.html
Holter testing/Echos prevent DCM. - I wish they did. Unfortunately, many dogs who tested clear/normal have died later on of DCM.
Grain free foods cause DCM. - Maybe. There is a lot of strong evidence suggesting a link between grain free diets and nutritional DCM. Where that line falls in dobes, between nutritional and hereditary, is extremely blurred. It is best to err on the side of caution and feed a well rounded, inclusive diet.
Raw feeding like BARF prevent DCM. - Nope. Many raw fed dogs still go on to develop DCM. The only diet scientifically linked to DCM is grain free. Often raw feeding leads to nutritional deficiency. Raw feeding in some cases may help reduce the rate of kidney disease as dry kibble tends to be really hard on a dog's urological system. A raw fed dog should be strictly monitored by their vet.
Supplements will prevent or cure DCM. - How I wish it was a simple as that. Human models show some promise in supplementation with l-arginine as a management aid as well as a way to prevent and reverse DCM but no such studies exist in Doberman or other dog breeds. Supplements should never be a replacement for medication or vet care.
DCM is always fatal. - Not always, just usually. Predictably usually. Non-hereditary and dietary DCM can be managed and sometimes reversed with early intervention and extensive treatment. Nutritional DCM can be reversed in most early and mild cases. The type/method of DCM in Doberman tends to be a silent and sudden killer making treating it difficult.
Stem Cell Therapy can cure DCM. No, it can't cure DCM but may be a good treatment. Stem Cell Therapy is still a new industry and needs more study and time to show if it is an effective treatment. It shows promise, but is extremely expensive and not easily accessible. For now, it just is not a practical option for managing DCM positive dogs.
Gene Therapy can cure DCM. - A study is currently underway (end in 2/2022) and shows promise for gene therapy as a way to MANAGE DCM and slow it's progression. It is a potential potent treatment option but can't cure DCM. "Gene transfer strategies to reduce calcium cycling abnormalities improve heart function in animal models as well as in human clinical trials. In this study, Dr. Sleeper will conduct a placebo-controlled, double blinded study to evaluate gene delivery approaches for treatment of Doberman Pinschers affected with DCM and CHF. If results show that the gene delivery slows progression of heart failure in Dobermans with DCM, the results will have significant ramifications for all dogs with heart disease, as calcium handling proteins are abnormally expressed in dogs with heart disease of varying causes."

Doberman Diversity Crisis, Diet, and DCM as an Autoimmune Disease

DCM Autoimmune Disease Study

DCM isn't just genetic related, there is a diet component too. There is a strong link between DCM and diet in several breeds. Vets noticed a sharp increase in DCM cases in breeds not typically prone to DCM. Many pet owners went to the FDA and complained about thier pet's health, which promptly the FDA to look into the matter. While research into the exact cause is still in process one thing is certain; fad diets are bad for our dogs. Fad diets include grain-free, exotic meats, meat only diets, BARF, raw diets and vegan (please, don't feed your omnivorous pet a plant only diet; it will kill him). Avoid trending diets and cures (such as tea tree oil, coconut oil, garlic - which is TOXIC to dogs, and so on). The evidence is solid; fad diets are hurting our pets. But what else may be? Many external factor have an effect on the disease. DCM is complex and hard to predict.

Doberman are one of the most inbred of all the dog world. All Doberman share the same 10 halotypes. That means they are all so closely related to one another it is as if breeding family members together! The average inbreeding ratio is 36%! There is not much diversity left to support healthy dogs and sustain a stable population for long. Lack of diversity gives rise to genetic mutations being passed down more frequently (homozygosity). The smaller gene pool the more the traits are shared.

https://plearl.wordpress.com/2019/05/08/pdk4-and-canine-dcm/
Doberman Genetic Crisis - https://www.instituteofcaninebiology.org/blog/an-update-on-the-genetic-status-of-the-doberman-pinscher
https://www.instituteofcaninebiology.org/blog/are-we-watching-the-extinction-of-a-breed-or-why-are-we-focused-on-consequence-instead-of-cause
Doberman Longevivity Study - https://www.veterinarypracticenews.com/uf-announces-lifetime-study-on-fatal-heart-disease-in-doberman-pinschers/
Doberman Diversity Project (open to select populations) - https://www.dobermandiversityproject.org/
Grain Free Diet/Nutritional DCM - https://news.vin.com/vinnews.aspx?articleId=52712
https://www.vin.com/apputil/content/defaultadv1.aspx?meta=&pId=11149&id=3846592
Rates of DCM - https://www.ufaw.org.uk/dogs/doberman-pinscher-dilated-cardiomyopathy
Predictors of DCM - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4913570/
DCM Related Autoantibodies - https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0214263

The Complexity of DCM Etiologies

DCM is a multifaceted disease with complex etiology. DCM may also be polygenetic and non-hereditary. Disorders such as thyroid disease, endocrine disease, autoimmune dysfunction can cause DCM. "A diverse array of causes for DCM have been identified for both humans and canines including genetic mutations [1,20], infection and autoimmunity [21,22,23,24], toxin exposure like alcohol and cytostatics [25,26], metabolic dysfunction and nutritional deficiencies [26,27,28], and even pregnancy [24,29]. Nevertheless, idiopathic and familial DCM are among the most frequently reported causes [12]." - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9265105/ Gene penetrance effects how affected by the disease the dog is. In human studies familial inheritance has shown to be an autosomal dominant pattern. There is emerging evidence that epigenetics has a strong role in the development of clinical DCM. "Despite of the progress, the genetic basis of a significant portion of the DCM patients remains unknown. Heterogeneity of disease phenotypes caused by mutations in the same gene raise points to complexity of factors involved in determining the clinical phenotype. There is an emerging recognition that phenotypic traits are not only determined by genetic variants of coding sequences at DNA level but also contributed by the functional state of the genome, which mainly dictates how genes are expressed. Consequently, the epigenetic studies mostly focus on the regulatory mechanisms and the functional consequences of the changes in gene expression rather than the changes in gene sequences. Recent advancement has revealed a growing importance of epigenetic regulation and dysfunction in human physiology and diseases" - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6581652/ Dobermans from around the world develop DCM, including European Dobermans (https://www.sciencedirect.com/science/article/abs/pii/S0195561610000343?via%3Dihub). "Typically, DCM in dogs is more prevalent in males than in females (Oyama, 2015). More specifically, Doberman Pinschers have a reported incidence rate of 50% in males and 33% in females (Oyama, 2015)..." There may not be a singular answer as to why a dog developed DCM. "If one considers the estimated total number of dogs in the United States equals 77,000,000 (AVMA, 2019), the published incidence studies (Fioretti and Delli, 1988; Sisson et al., 2000) suggest that a minimum of 308,000 to 1,001,000 dogs in the United States have DCM at any given time." - https://academic.oup.com/jas/article/98/6/skaa155/5857674 DCM is the second most common cardiac disorder in canines.

"Historically, DCM has been primarily linked to a genetic predisposition in certain breeds, but emerging science appears to indicate that non-hereditary forms of DCM occur in dogs as a complex medical condition that may be affected by the interplay of multiple factors such as genetics, underlying medical conditions, and diet. Aspects of diet that may interact with genetics and underlying medical conditions may include nutritional makeup of the ingredients and how dogs digest them, ingredient sourcing, processing, formulation, and/or feeding practices. Reports from veterinary cardiologists demonstrate some good results in improving heart function in non-hereditary DCM cases, unlike genetic forms of DCM, with appropriate veterinary treatment and dietary modification, when caught early in the progression of the disease." - https://www.fda.gov/animal-veterinary/animal-health-literacy/questions-answers-fdas-work-potential-causes-non-hereditary-dcm-dogs#:~:text=Historically%2C%20DCM%20has%20been%20primarily,genetics%2C%20underlying%20medical%20conditions%2C%20and

Inbreeding is a real and serious consideration for the development of DCM. In the 90's DCM already affected about 25% of the breed. Each year since the occurrence rate increases 1.5%. (https://www.instituteofcaninebiology.org/blog/an-update-on-the-genetic-status-of-the-doberman-pinscher) The average coefficient of inbreeding in Dobermans is 36%, according to Embark Vet. Inbreeding is associated with decreased life expectancy and poorer health.

Why What was Recommended isn't Working

"Clearly, the efforts made by breeders over the last three decades to decrease the incidence DCM have had no effect at all on the prevalence of the disorder. Not even a little." - Carol Beuchat PhD

The above chart on the left shows a striking and steady increase in DCM in the Doberman breed. The chart above on the right shows a sharp decline in the breeds life expectancy. Efforts to reduce DCM have been ineffective. Efforts such as the Holter Project failed to reduce DCM rates by avoiding DCM families and DCM positive dogs. There is clear evidence that DCM is on the rise and longevity is in decline.

Echos, auscultations and holter monitoring are excellent diagnostic tools but have limitations. They are only a SNAPSHOT into the cardiac function at that time and for that duration. They are not a guarantee against developing the disease.

"Recommended Testing Protocol for Cardiac Disease. Annual echocardiograms (an ultrasound of the heart), together with 24 hour Holter Monitoring, provides a snapshot of a dog's current heart health at that moment in time. Your vet can also perform a simple blood test that measures the concentration of NTproBNP in your dog's blood and is a good indicator of heart health. It is important to understand that test results can be normal one year and a dog can show signs of DCM the very next year. This is why breeders must perform ANNUAL heart screening. Two DNA genetic tests are available; they identify two mutations (PDK4) and DCM2) that are thought to be associated with DCM. The tests involves a simple cheek swab and don't necessitate a veterinary visit."
https://www.dobermandiversityproject.org/diseases.html

DCM Genes are IMPORTANT

"Important note about the TTN mutation (also known as DCM2): The vast majority of research exploring the genetics of DCM has been performed on purebred American Dobermans, a high risk population for DCM. Even in the Doberman, DCM2 is incompletely penetrant, meaning that while having one or two copies of this mutation is thought to confer some increased risk of developing DCM, it is by no means predictive of disease. DCM is a highly complex disease that is modulated by many genetic factors, most unknown. In addition, Embark and others have identified this mutation in multiple breeds, including breeds where DCM is not a common disease. The impact of this mutation in these breeds is unknown: Embark hopes to change this." - Embark on TTN/DCM2

an_update_on_canine_cardiomyopathies
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