Is Your Dog’s Food Breaking Her Heart? An Inside Look at Grain-Free Diets and Heart Disease

In July 2018, the Food and Drug Administration (FDA) announced it was investigating reports of dilated cardiomyopathy (DCM) in dogs eating certain pet foods. Many of these reports included small or medium-size breeds not typically known to develop DCM. If your pet is eating a BEG diet (i.e., a diet that includes boutique, exotic, or grain-free foods), you may want to reconsider your food choice to avoid its potential link to heart disease.

What is a BEG diet?

A BEG diet has three components:

• Boutique diets, which are manufactured by small companies that often do not conduct food trials or invest in a board-certified veterinary nutritionist, and may instead opt to fund flashy marketing campaigns to appeal to pet owners
• Exotic diets, which are formulated with exotic meats, like kangaroo or squid
• Grain-free diets, which have exploded in popularity due to extensive marketing and which play on the low-carb diet fads in human nutrition; these diets include potatoes, peas, lentils, and other legumes instead of the commonly used corn and rice

These three pet-food types are popular with pet owners due to marketing that plays on the shift in human diets toward healthier, low-carb options. However, animals do not digest food like people and have different nutritional requirements. Your pet’s diet should be based on her specific needs and follow the World Small Animal Veterinary Association’s nutrition guidelines.

What is canine dilated cardiomyopathy?

DCM is a genetic condition diagnosed in large- and giant-breed dogs, such as Dobermans, Great Danes, Irish wolfhounds, and boxers, that causes heart muscle weakening and enlargement and can lead to congestive heart failure and death. The first sign of DCM is often a heart murmur or arrhythmia your family veterinarian hears during a routine physical exam. As the disease progresses, your dog may display the following signs:

• Exercise intolerance
• Increased breathing rate and effort
• Coughing
• Sudden weakness
• Fainting
• Abdominal enlargement due to fluid accumulation

Regular check-ups are crucial to allow your veterinarian to catch this disease in the early stages and to promptly treat your dog’s heart condition. If your pet has been eating a boutique, exotic, or grain-free diet, schedule an appointment for an evaluation of her heart function.

How are BEG diets and DCM linked?

The link between diets containing legumes and exotic meats and DCM is still unclear, but research continually exposes new theories. Here’s what is currently known:

• More DCM cases are being seen in dogs who have been eating BEG diets, but they are only a small portion of the dogs eating these diets.
• Some DCM cases are believed to be due to a deficiency of taurine, an amino acid found in animal protein only and not in plants.
• Taurine deficiency is not the cause in all DCM cases. Many dogs have normal taurine levels in their blood, which may indicate an absorption issue. Minimal research has been performed on exotic ingredients, and whether the taurine from an exotic meat is absorbed when combined with legumes is unclear.
• Some dogs with DCM and normal taurine levels improve with a simple diet change, which suggests a different nutrient deficiency or even a toxicity related to BEG diets.
• Problems with BEG diets may be due to incomplete nutritional research. Smaller companies do not have the resources to test the foods and ensure quality control. More studies are needed to determine how processing affects foods and how ingredients, especially exotic ones, interact and affect absorption.

What if my pet has a food allergy?

Many owners do not understand their pet’s food allergies and believe the myth that their pet is allergic to the corn or grain in the diet. Pets are much more likely to have an issue with a food’s protein source. The most common allergens in pet foods include:

• Chicken
• Beef
• Dairy
• Eggs
• Fish for cats

Pets with a chicken or beef allergy may do better on a novel protein diet, such as one that uses duck or venison. Always carefully examine the ingredient list on a duck-based food, because poultry by-products or chicken fat often are hidden in the list. Over-the-counter foods are also a concern because most are manufactured in a plant that makes other foods as well, leading to cross-contamination.

The only foods completely free from animal protein contamination are prescription diets using hydrolyzed proteins. During manufacture, one round of the hydrolyzed diet is processed and disposed of, with the second round then deemed free of potential contamination and packaged for consumption. This process helps explain why hydrolyzed diets can be costly. Although chicken causes most food allergies, hydrolyzed protein diets often feature chicken or soy protein, but hydrolysis breaks down the protein source into small molecules that the body does not recognize as an allergen and they bypass the immune system.

What should I feed my dog?

Since the link between grain-free diets and heart disease is still not understood, pet owners are advised to switch pets from grain-free foods, unless the benefits outweigh the risks.

Brands that have documented cases of Nutrition related Cardiac Disease:

Acana, Zignature, Taste of the Wild, 4Health, Earthborn Holistic, Blue Buffalo, Nature’s Domain, Fromm, Merrick, California Natural, Natural Balance, Orijen, Nature’s Variety, NutriSource, Nutro and Rachael Ray Nutrish.

Brands that have not had any reported cases:

Royal Canin, Hill’s Science Diet, and Purina Pro-Plan

For pets with known food allergies, a hydrolyzed protein diet is recommended.

So now what?

The main take away is, while we do not know the exact mechanics causing heart disease in these canines, it’s likely best to remove them from BEG diets. True clinical studies will take awhile before we get information from them. Also remember the dogs affected are likely still a low percentage of dogs eating BEG diets, so while we are concerned, we are not panicking about this information. If you have any further questions, please contact your veterinary professional.