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Grain Free Food and Heart Disease

Trendy foods causing heart disease in dogs

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What we know

In early spring of 2018 Dr Stern, a cardiologist from UC Davis, raised the alarm.  He published an article describing a spike in a heart condition called Dilated Cardiomyopathy(DCM) in breeds with no genetic predisposition.  These dogs were being fed Grain Free dog foods, boutique foods with exotic ingredients or Raw Diets.  Dogs were dying of a typically rare and breed specific heart disease and he thought the foods were related.

DCM is a disease where the heart dilates until it becomes a floppy bag that is unable to contract and push the blood through the body.  This particular form of heart disease is nefarious for not showing signs before the heart has been catastrophically damaged.  Lucky dogs may develop a heart murmur that can be detected at an annual wellness/vaccine visit, others are found when the dog collapses because the brain is not getting enough oxygen during exercise and some will just suddenly die as the electrical impulses that power the heart cannot work in such an enlarged heart.  This condition was a problem in cats when cat food production was first commercialized.   Cats require supplementation of the amino acid taurine as they cannot make it in their body.  Once this was understood, cat foods were supplemented with taurine and the incidence of DCM in cats was almost completely eliminated.  A few breeds of dogs have a genetic predisposition to DCM, but it is a reasonably rare condition for dogs as a whole.

In late summer 2018 the FDA released a statement of concern and wanted any suspected cases reported.  They released preliminary results several months later that had identified 300 cases of what has now been coined Nutritionally mediated Dilated Cardiomyopathy(NmDCM).  Seventy of those dogs had died due to the condition.  Cardiologists had speculated that taurine played a role and were recommending supplementation and switching to traditional diets with traditional ingredients.

In late winter 2018/19 Dr Stern published a journal article showing that the food was the problem.  He took a group of golden retrievers with NmDCM(suspected at that point).  Returned them to a traditional diet (food with grains, no exotic ingredients, balanced), from a company that tested each batch of food produced and had conducted food trials.  He also supplemented them with taurine.  Their hearts started to heal.  Now we know the cause of NmDCM is food related and we know that this condition is not only reversible if caught early but it is preventable.

That is what we do know.  There is a lot that we do not know at this point.  Research is ongoing and in the future, will shed more light on this condition.  What we do know is that feeding foods that are grain free, contain exotic protein sources or raw diets are causing some dogs to develop a life threatening disease.  We recommend switching to a diet that is not implicated until we have a better understanding of this disease process.

What should I do if I am feeding one of these diets?

We recommend booking a nutritional consult with one of our veterinarians.  We will go over the food that has been fed and help you find a food that is safe and that meets your pet’s healthcare needs.  We will listen closely to the heart and make sure that there is no murmur or abnormal rhythm.  A discussion of testing should be done as this disease can be quite advanced before any signs or symptoms will be present. Here are some of the recommended tests:

  • ProBNP – A test for a protein that is released when the heart is damaged.  It will catch most but not all dogs with DCM.

  • X-rays of the heart – We measure the heart and compare it to the size of the bones in the spine to see if it is enlarged (an objective way to measure heart size called VHS or vertebral heart score).  This test will catch most dogs with DCM but may not identify dogs that have a mild form of the disease.

  • Blood Taurine levels – We have seen that not all dogs with NmDCM have low taurine.  This may not be a good screening test, but is useful in guiding treatment.

  • Echocardiogram(ultrasound of the heart) – This test is ideal and will diagnose or rule out DCM.  It is performed by a specialist or someone with a lot of training in ultrasound.  It can be expensive and wait times for the procedure are increasing.

How did we get here?

The short answer is marketing.  Some dog food companies wanted to sell more product so they formulated diets based on what resonated with the public.  Grain free came about because people were trying to eliminate grains from their own diets.  The increased awareness of gluten intolerance in people, which is real in people, but not in our dog population.  Grain free resonated with the public so it was marketed as the healthy choice.  It was not based on a nutritional study showing a benefit to the dogs eating the food.  Formulating a grain free diet is not easy, so ingredients never used before in pet foods became common place.  Ingredients like lentils, green peas, tapioca, sweet potato and potato popped up on ingredient lists.

Misinformation marketing came second.  Many food companies and retail sales associates then provided misinformation to the consumer to firmly hold their market access.  Statements like corn is unhealthy, wheat will cause allergies and cancer, and byproducts are dangerous.  All of these statements are incorrect.  They are scary to the consumer who is trying to choose the healthiest option for their pet.  

None of this had to do with the quality of the food or the health of your pet, but rather market share and profits.  These companies did not intend to cause harm to pets, but the amount of money put in to research and clinical trials was very small compared to that invested in marketing. 

Pet food ingredients should be selected based upon scientific findings, and diets should be formulated from good research and tested through feeding trials. 


This website has compiled much of the reference material available.  It has copies of FDA statements and published research, frequently asked questions and stories of affected families

Taurine-Deficient (Nutritional) Dilated Cardiomyopathy Facebook Group

A facebook group with educational "units" so that pet owners can educate themselves.  This page also acts as a support group to affected families.

The Bean

Check out our blog page!

Drs Hodges and Dr Jameson's dog, The Bean, has been affected by this condition.  Dr. Hodges wrote two blogs about it.  Blog 1 was written before we knew that diet may play a role in this disease.  Blog 2 was written once it was proved that this disease was caused by nutrition.

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