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Featuring Demian Dressler, DVM and Sue Ettinger, DVM, Dip. ACVIM (Oncology), authors of The Dog Cancer Survival Guide

Does Grain-Free Dog Food Cause Heart Disease?

Updated: November 12th, 2021


Grain-free dog food seems to be a risk factor for heart disease in dogs, but we don’t know why yet. So what should you feed your dog?

Grain-free dog food has been in the news since 2018, when the FDA announced a correlation between these diets and dilated cardiomyopathy (DCM) in dogs.

We recently received a question on the Dog Cancer Answers Listener Line about this topic and decided to explore it.

Dr. Nancy Reese, integrative oncologist Dr. Kendra Pope, and veterinary technician Kate Basedow, LVT weighed in on what DCM is, what we know so far, and how to decide what to feed YOUR dog (full podcast episode below).

First, let’s take  look at what is Dilated Cardiomyopathy (DCM).

Dilated Cardiomyopathy

Dilated cardiomyopathy is a condition where the ventricles of your dog’s heart stretch out and become weaker.

This makes it more difficult to pump blood to the body.

Eventually, it will lead to heart failure.

DCM has been around for a long time, and certain breeds, such as Dobermans and Boxers, are more likely to have a genetic risk.

Dilated cardiomyopathy leads to heart failure.

To diagnose DCM, your dog needs to have an echocardiogram, or ultrasound, of the heart. This procedure can usually be done with your dog awake and lying on her side, but requires a specialist.

Classic DCM is a progressive disease. It can be slowed with medications, but will not improve.

Symptoms of DCM include:

  • Cough
  • Difficulty breathing
  • Weakness or exercise intolerance
  • Collapse
  • Sudden death

That’s a really scary list of symptoms, right?

Most folks feed their dog a grain-free diet because they think it’s healthier than regular diets.

So why does the FDA think these boutique diets could be related to rising DCM rates in dogs?

What the FDA Found

First, the FDA noticed an increase in cases of DCM in dogs that didn’t fit the classic profile. They weren’t just finding DCM in Dobermans and Boxers … the new cases were in younger dogs, and in breeds and mixes that don’t typically get DCM.

They also noticed that a large number of these atypical cases were eating grain-free, boutique diets.

The FDA announced this to alert dog owners to a potential risk in feeding these diets.

Ever since then, researchers have been working to verify that the diets were indeed to blame…

…and to figure out what exactly about these diets is causing DCM in dogs.

What We Know So Far About DCM and Grain-Free Diets

To date, we don’t yet have a black and white answer on what exactly causes some dogs to develop diet-related DCM.

Here’s what we do know:

  • Not all dogs who eat grain-free dog food will get DCM.
  • Dogs with diet-associated DCM usually improve with a change of diet. More severe cases may need medication to help them improve, but in general, symptoms are reduced, and/or the heart returns to normal appearance and measurements on ultrasound.
  • Many of the diets implicated in this issue swap out grains for legumes such as peas, lentils, and potatoes.
  • A 2021 study from Tufts University found that two of the ingredients that differed between grain-free diets and grain-inclusive diets were peas and lentils.
  • Taurine deficiency is sometimes also present, but not usually.
  • These “non-traditional” diets with peas, lentils, and/or potatoes may have early negative effects on the heart even in dogs that appear healthy.

What Should I Feed My Dog?

The World Small Animal Veterinary Association recommends feeding a diet made by a company that has either a boarded nutritionist or a PhD in animal nutrition on staff.

You may hear references to the “big five” dog food manufacturers: Purina, Iams, Eukanuba, Hills, and Royal Canin.

But just because a dog food company is smaller doesn’t mean it can’t get help from a boarded nutritionist of a PhD in animal nutrition.

If you think about it, really, any dog food company should be willing and able to answer any questions you ask about their quality control measures and manufacturing processes.

My Dog is Eating Grain-Free Food. Should I Switch?

That’s the question, isn’t it? Here are some things to consider.

  • If your dog has been diagnosed with dilated cardiomyopathy, switch to a traditional diet that does not contain legumes. Follow up with your dog’s cardiologist on a regular basis to see if your pup’s heart improves.
  • If you have a breed that is genetically predisposed to DCM, avoiding boutique diets may be a good choice to eliminate one layer of risk.
  • For a dog with close relatives with heart issues, avoiding grain-free diets may be a good choice to eliminate one layer of risk.
  • If you are happy with your dog’s current diet, you don’t have to switch. Just keep the possible risk of DCM in the back of your mind.

If you’ve been feeding your dog a boutique, grain-free dog food formula, and you are worried about symptomless DCM, get him or her screened with an ultrasound.

Things To Consider

Not every dog who eats a non-traditional, grain-free, or boutique diet will get diet-associated DCM. Diet impacts the health of every cell in the body, so DCM is just one of the factors to consider when choosing what to feed your dog.

It all comes down to your dog’s individual case and your tolerance for risk.

The most important thing is that your dog’s diet is complete and balanced.

There is no way to completely avoid all risk when feeding your dog. For example, if you cook meals for your dog, she can still be at risk for diet-associated DCM.

Always use a recipe formulated or reviewed by a veterinary nutritionist to be sure that your dog is getting everything she needs. A good resource for this is

If your dog has cancer, you still want to minimize carbs so that you can starve out those cancer cells. You just don’t want to include legumes, right?

Keep in mind that Dr. Dressler’s diet, for example, does NOT include any legumes in it at all, because they are high in starch.

To find out more, you can read the full transcript of the interviews on the Dog Cancer Answers episode page.

And here is the video version of the podcast:

Please subscribe to, rate, and review Dog Cancer Answers in Apple Podcast or on your favorite pod-catcher. It really does help the show!

Paws and wags,


PS: Feel free to share this article or the podcast itself with your veterinarian and their staff.

Have a Great Question for Dog Cancer Answers Veterinarians?

Call the Listener Line at 808-868-3200

Further Reading and References:

FDA 2019 Update on Dilated Cardiomyopathy and Dogs

Investigation of diets associated with dilated cardiomyopathy in dogs using foodomics analysis

Development of plasma and whole blood taurine reference ranges and identification of dietary features associated with taurine deficiency and dilated cardiomyopathy in golden retrievers: A prospective, observational study

Effect of type of diet on blood and plasma taurine concentrations, cardiac biomarkers, and echocardiograms in 4 dog breeds

WSAVA Global Nutrition Committee: Guidelines on Selecting Pet Foods 2021 Update

Dr. Dressler’s Dog Cancer Diet

Diet and Dogs with Cancer

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