Updated July 2019 You may have heard rumblings in the news recently about a link between a grain-free diet in dogs and increased risk of dilated cardiomyopathy, otherwise known as DCM. Our vets are understandably getting a lot of questions from concerned pet parents about the issue. Here's what they want you to know.
What's the News?
In the summer of 2018, the FDA began researching a possible link between certain diets in dogs and the onset of heart disease. As a result of this research, they released a report on June 27th, 2019, that shows a correlation between certain dog foods, most of them labeled "grain-free," and dilated cardiomyopathy.
What is Dilated Cardiomyopathy (DCM)?
DCM is a condition in which a dog's cardiac muscles lack the strength necessary to efficiently pump blood. It is, specifically, the dilation of the ventricles, usually accompanied by wall thinning. Dogs with DCM have trouble pumping enough oxygenated blood through their bodies which can result in weakness, lethargy, weight loss, respiratory issues, coughing, abdominal distention, or collapse. It can result in cardiac arrhythmia - irregular heartbeat - which in some cases can lead to death.
So, Grain-Free Diets Cause DCM?
Not exactly. The FDA makes it clear that their findings do not conclusively show that grain-free diets cause DCM. Correlation is not causation; just because there's a correlation between the diet and the condition doesn't necessarily mean one is responsible for the other. The development of DCM is complex and involves a multitude of factors. Some dogs are predisposed to the condition based on their breed. Others may develop DCM as a result of an infection or as a side-effect of other individually-specific nutritional deficiencies. Breeds that are most at-risk of developing DCM are giant breeds such as the Doberman Pinscher, the Great Dane, and the Boxer, as well as the Cocker Spaniel.
Should I Stop Feeding My Dog Grain-Free Food?
Unless otherwise directed by your veterinarian, it is our recommendation that if you are feeding your dog a food labeled "grain-free," you should transition her to a different diet. We also recommend making this transition if you are feeding your dog fresh or homemade food that contains a high proportion of peas, lentils, other legume seeds, and/or potatoes in various forms (whole, flour, protein, etc.). The top 16 dog food brands eaten by dogs who developed DCM in the FDA's study are as follows: Acana, Zignature, Taste of the Wild, 4Health, Earthborn Holistic, Blue Buffalo, Nature's Domain, Fromm, Merrick, California Natural, Orijen, Nature's Variety, NutriSource, Nutro and Rachael Ray Nutrish. Diet transitions should always be done under the supervision of a vet. Changing your dog's diet could create other nutritional deficiencies or imbalances if you're not careful. A food transition should be made gradually to avoid causing undue gastrointestinal distress.
Why Do We Recommend This?
There is no definitive link between grain-free diets and dilated cardiomyopathy. That being said, until more study has been done, we believe that in most cases the potential risks outweigh the potential benefits. Well-meaning pet parents choose grain-free food for their dogs because they believe it is more easily digested, useful for weight loss, or helpful in treating food allergies. All of these reasons are valid, but potentially addressed in other ways. Talk to your vet about why you've chosen a grain-free diet for your dog in order to come up with an alternative.
How Do I Know If My Dog Has DCM?
In some cases, DCM (and other heart diseases) present subtly, at least at first. Symptoms might include decreased energy, excess sleeping, or a persistent cough. Diagnosing DCM usually involves echocardiography and/or use of an electrocardiogram. More serious signs of DCM include difficulty breathing or collapse. If your dog is suffering from either of these symptoms we advise you to rush her to the closest emergency veterinary clinic. Immediate action can be life-saving in these scenarios.