Diet-associated DCM in Dogs: Veterinarians Share Their Thoughts

Is your dog eating a grain-free diet? Are you concerned that your dog can develop a diet-associated DCM?

I’m afraid that this article will not put you at ease.

There obviously is a problem that is hurting the hearts of the affected dogs. The suspected culprit lies in foods that contain a high proportion of the following ingredients:

peas
lentils
other legume seeds (pulses)
potatoes in various forms

Correlation does not automatically mean causation. Still, when a problem arises, one ought to start somewhere. The problem is new, and the dog food formulas are new.

What is DCM?

Dilated cardiomyopathy is a disease of the heart muscle tissue. Namely, the walls of the heart’s main pumping chamber enlarge and weaken. As a result, the heart loses the ability to pump blood properly. All of your dog’s body tissues need blood and the oxygen, nutrients, and immune cells it caries.

DCM leads to congestive heart failure. All that is very bad news.

What does all that have to do with grain-free diets?

That is what the FDA is investigating. Specifically, the FDA is looking into the potential correlation between these dog food formulas and taurine deficiency.

Except the issue is far from that simple.

Conflicting findings

For example, not all affected dogs were taurine deficient. Some dogs diagnosed with diet-associated DCM had low taurine levels but some did not. Regardless, though, most dogs with early diagnosis improved with a change of diet.

The issue does not affect all dogs who eat grain-free diets. The estimation is that about twenty million dogs are eating these foods. FDA received reports of 515 cases.

Source: weethnutrition

Breed distribution

Formula distribution

Dry food formulas stand out the most. 452 of affected dogs were on dry grain-free foods out of a total of 515.

What do I think?

Well, I think that the bulk of dog diet should be animal-source ingredients. To me, evolution was the largest feeding trial. And the historical diet included neither grains or legumes.

That said, grains are time tested. Legumes are not.

Some of the brands formulate their foods according to the AAFCO guidelines. This, to me, makes nutritional deficiencies less likely. But just because the nutrients are present, it doesn’t mean they are in a form a dog’s body can use.

As well as legumes might contain something that interferes with absorption or utilization. And there is a chance that the issue is not the ingredients themselves; or the foods for that matter.

The problem is that we don’t know.

I’m conflicted about this report. On one hand, certain pet food manufacturers have taken a cavalier approach to their diet’s potential role … On the other hand, the FDA’s report paints a broad stroke over specific brands … This is a less than helpful oversimplification of a complex problem.
LP Weeth, DVM, DACVN

What don’t we know?

We don’t know

the full scope of the problem
where the problem is coming from
whether the problem is an ingredient, dog, manufacturer, or all three
if the percentages of the reported brands represent their market share or a problem with the companies

Source: weethnutrition

In such a complicated, confusing and unclear situation, my instinct is to err on the side of caution.

Veterinarians answer

Only a couple of my veterinary friends agreed to participate and contribute their take. That tells you how difficult this subject is.

Dr. Patrick Mahaney

1. Have you seen any dogs who suffered from this condition in your practice?

I currently have one Golden Retriever patient having concerns for dilative cardiomyopathy potentially correlating with diet.

The patient’s heart disease is being managed by a veterinary cardiologist who helped to put further belief in the potential that the patient’s diet could be a contributing factor to the current degree of heart disease.

2. What diet were they on?

The patient has been eating a locally-prepared (Los Angeles), commercially-available, cooked, whole-food diet that unfortunately is not nutritionally complete nor balanced and is marketed to be grain-free with components including rabbit as a novel animal protein along with lentils and peas as grain-free carbohydrate sources.

3. What do you make of the situation?

I have never been one to recommend an exclusively grain-free diet for my canine patients. As dogs are omnivores with a trend towards being carnivorous they are able to eat a variety of food sources to promote optimal sustainability of life and from my veterinary education and observations in practice I see dogs having dietary variety generally being healthier.

Yet, if an owner feels compelled to go in the direction of feeding exclusively one diet or one combination of proteins and carbohydrates throughout a pet’s life without having nutrient variety then there is potential that dietary insufficiencies and health problems can occur.

Such is why I recommend my patients eat a rotational diet that is nutritionally complete and balanced. This way, the body will be exposed to nutrients of varying sources having differing absorbability each time the food is changed.

Dr. Christopher Byers

Effective pumping of blood either to the lungs or to the body is an intricate function of the heart, one that requires healthy heart muscle cells. These cells are called cardiac myocytes and any dysfunction of them is called a myopathy.

The most common heart muscle disease in dogs is dilated cardiomyopathy (DCM). Recently, the Food & Drug Administration (FDA) evaluated hundreds of reports of dogs with DCM eating non-standard diets for the past decade. The implicated diets are grain-free, vegetarian/vegan, home-prepared but not formulated by a board-certified veterinary nutrition specialist, and/or contain an exotic ingredient. These diets are often referred to as BEG diets – boutique diets, exotic ingredients, and/or grain-free.

To date, I’ve not personally evaluated a patient with DCM being fed one of these unique diets. But, I’m sure it’s only a matter of time. So, what do you need to know at this time?

Several cases reported to the FDA involved dogs with low taurine levels

Taurine is a conditionally-essential amino acid, and main sources include meat, fish, and dairy. Vegetarian foods don’t provide sufficient quantities, and taurine supplementation is often needed for these types of diets. Taurine deficiency is well-documented as potentially contributing to the development of DCM. There are reports of dog breeds that aren’t usually affected by DCM. Many of these patients had documented normal taurine levels. As veterinarians, we need to better understand if (and how) taurine metabolism plays a role canine dilated cardiomyopathy in patients fed BEG diets.

Some dogs eating BEG diets have no clinical signs of DCM

According to board-certified veterinary nutrition specialist, Dr. Lisa Freeman, most dogs eating BEG diets are unlikely to develop DCM. However, given DCM is life-threatening, pet parents may want to reconsider their pet’s diet until we know more.

Clinical signs of DCM

Pet parents should familiarize themselves with the clinical signs of DCM in an effort to identify this heart muscle disease early in its course. Clinical signs for which families should monitor are:
• Exercise intolerance
• Increased respiratory rate
• Coughing
• Collapse
• Fainting
• Blue/purple hue to tongues and gums
A veterinarian should evaluate as soon as possible any dog observed to have any of these clinical signs.

Reporting

Pet parents who believe their dog has developed diet-associated DCM should report the incident to the FDA as soon as possible. This may be done in partnership with their veterinarian or directly to the FDA.
Pet parents are strongly encouraged to seek the counsel of their veterinarian for nutrition information. I’m excited to see what continued research in this area produces, as it is undoubtedly a topic about which we have so much to learn!

Dr. Shawn Finch, DVM

I have not seen this in my practice but am steering people away from the diets on the FDA list – not necessarily the brands, just the specific diets that have been implicated.

People feel so strongly about their dogs’ diets (and rightly so), but there has become a disconnect between clients and veterinary diet recommendations. Perhaps this issue will swing clients back towards trusting their vet teams to help with diet recommendations. I hope so.

Our local situation

Our local veterinary hospital is seeing young dogs who should not get DCM with severely enlarged hearts. Just recently they posted radiographs of a heart that belongs to a 3-year-old Lab cross. Cardiac ultrasound confirmed the dog has dilated cardiomyopathy (DCM).

The x-rays below belong to a second young dog who has been diagnosed with DCM that day and tenth this summer alone. It is not a large hospital.