DCM stands for dilated cardiomyopathy, a type of heart disease. The possible causes of DCM in dogs are widely debated: from genetics, to taurine deficiency, to grain-free dog foods.
Let’s look at the signs of DCM in dogs and then explore the causes and possible treatment options.
What Is DCM In Dogs?
Dilated cardiomyopathy , or DCM in dogs is a disease that makes it harder for the heart to generate pressure to pump blood through the vascular system.
DCM Dog Breeds
DCM primarily affects large and giant breed dogs. It’s particularly common in a few specific dog breeds, including:
- Doberman Pinschers
- Irish Wolfhounds
- Great Danes
- Cocker Spaniels
However, in recent years, reports have shown DCM occurring in breeds which don’t usually get this disease, including Golden and Labrador Retrievers, Whippets, Shih Tzus, Bulldogs and Miniature Schnauzers.
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What Are Signs Of DCM In Dogs?
Unfortunately, there are limited symptoms when it comes to the early signs of DCM in dogs. In fact, some dogs with DCM can have a very long pre-clinical phase where there are no symptoms at all. Some animals can even die from arrhythmias without having any previous symptoms.
However, when dogs do show symptoms, the following two signs of DCM in dogs are the most common:
1. Lethargy And Weakness
DCM interferes with one of the heart’s key roles: delivering oxygenated blood through the body. When this happens, weakness, fainting spells, weight loss, and even collapse are possible, especially in the later stages of the disease.
2. Respiratory Issues
DCM in dogs can also cause blood to become congested in the lungs. This can cause several respiratory issues, including coughing, a distended abdomen, and difficulty breathing.
Stages Of DCM In Dogs
DCM usually occurs in adult dogs middle-aged or older. The disease usually occurs in two stages. As mentioned earlier, many dogs will not exhibit any DCM symptoms during the early phases of the disease. This is sometimes called the “occult” or preclinical stage of the disease, during which most dogs will appear normal and healthy. Since DCM tends to affect older dogs, this phase can continue for a long time before any symptoms manifest.
The second, clinical phase is when the dog with DCM appears ill and starts showing symptoms. These will typically be the symptoms mentioned earlier, most of which are related to heart failure.
DCM In Dogs Life Expectancy
Unfortunately, even though there are some treatments that can prolong life expectancy, most dogs with DCM eventually die from the disease. The life expectancy can vary with different breeds. Cocker Spaniels tend to live the longest in the clinical stages of the disease, while Doberman Pinschers have the shortest expectancy once heart failure symptoms start to appear. Arrhythmias also put dogs at risk for sudden death at any time during the clinical stage of the disease.
Causes of DCM in Dogs
Nobody has nailed DCM in dogs down to one, definitive cause. A wide variety of factors are at play, including nutrition, infectious history, and genetics. However, it’s clear that DCM in dogs occurs more commonly in certain breeds. This suggests that there is a large genetic component to the disease.
However, there are also systemic conditions that can cause the heart to contract poorly, which may contribute to the disease.
These conditions include:
- Amino acid deficiencies (taurine in particular)
- Low thyroid levels
- Heart inflammation (myocarditis)
- Prolonged rapid heart rate
- Poor blood flow to the heart
Treatment For DCM In Dogs
There is no cure for DCM. But while treatment for DCM in dogs isn’t curative, it can still improve quality of life and life expectancy, and delay the onset of heart failure symptoms.
In dogs where an underlying deficiency is found to be causing the issue (like thyroid or taurine deficiency, for example), supplementation may be able to halt or reverse heart muscle changes.
Once dogs are in the congestive heart failure stage, treatment mostly comes down to the use of cardiac medications, which can dilate blood vessels and support heart muscle contraction. Dogs with irregular heart rates may be given specific medications to stabilize the heart rate and prevent arrhythmias.
Is DCM Linked To Grain-Free Foods?
In 2018 the FDA announced it was investigating a link between grain-free diets and taurine deficiency in dogs, which can lead to DCM in dogs. However, in December 2022 the FDA announced it had insufficient data to establish causality among DCM case reports and pet food products eaten by the afflicted dogs (1).
And there’s other research that suggests the investigation was a false alarm.
In June 2020 a group of veterinarians, veterinary cardiologists, and animal nutritionists published a report in the Journal of Animal Science (JAS) (2). The lead author said …
“We […] examined the results of more than 150 studies, which, taken together, did not support a link between grain-free and legume-rich diets and DCM. What the science does make clear is DCM is largely an inherited disease.”
And in the summer of 2022, the investigative group 100Reporters uncovered a story that strongly suggests the FDA investigation was prompted by certain veterinarians who may have been influenced by financial ties to the major pet food manufacturers. The report also found that there had been some cherry-picking of data that could steer people away from grain-free foods and back to more traditional grain-based recipes.
RELATED: Taurine might not be behind heart disease from kibble …
Diet For DCM In Dogs
Nonetheless, feeding a whole food, raw meat based diet will provide your dog with ample taurine and help avoid any deficiency. All dogs need taurine for the healthy development of their eyes, brains, heart muscle cells, and immune health.
To make sure your dog gets plenty of taurine, you’ll want to feed plenty of raw meat.
Poultry, fish, liver and other organ meats are great sources of taurine. It’s also present in hoofed animals, milk, and eggs, but in lower amounts. Plant proteins contain no taurine, so a vegetarian or vegan diet that’s not supplemented can cause taurine deficiency in dogs.
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- FDA Investigation into Potential Link between Certain Diets and Canine Dilated Cardiomyopathy, Update December 23, 2022
- Sydney R McCauley, Stephanie D Clark, Bradley W Quest, Renee M Streeter, Eva M Oxford, Review of canine dilated cardiomyopathy in the wake of diet-associated concerns, Journal of Animal Science, Volume 98, Issue 6, June 2020.