Grain Free Diets

With all the stories and posts in the media recently about grain-free diets and their link to heart disease, we have attempted to summarize the most current information available on the subject. The simple answer is, there is no simple answer.

The issue came to light when veterinary cardiologists in the US, Canada, Israel and Austria began noticing a dramatic increase in the number of dogs they were diagnosed with dilated cardiomyopathy. The cardiologists reported the emerging trend to the FDA, including the dietary information they collected as part of the dogs’ medical history. In July of 2018, the FDA released a statement that they were beginning an investigation into the potential link between diet and dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) is a condition where the heart muscle becomes stretched and thin, reducing the heart’s ability to circulate blood through the body. It can result in congestive heart failure, an accumulation of fluid in the lungs. There are multiple breeds that have a genetic predisposition to DCM, including giant breed dogs like Great Danes and Irish wolfhounds, Dobermen Pinschers, Portuguese water dogs, boxers and Cocker spaniels. Most notably about these recently diagnosed cases were being seen in breeds of dogs that do not commonly develop the disease.

With the collected data, the FDA determined that the most common factor in these cases was the use of non-traditional diets, specifically boutique, exotic-ingredient and grain-free diets (BEG diets). The most common carbohydrate sources found were legumes, including peas and lentils. There were a variety of protein sources, the most common of which was chicken and lamb.

Initially, it was thought that diet-related taurine deficiency was the culprit in the rise of DCM cases. Recently it has been determined that this is not always the case. The investigation has determined that affected dogs fall into three categories:

1. Dogs on BEG diets with normal blood taurine levels
2. ‘Typical’ breeds predisposed to developing DCM
3. Diet associated DCM with taurine deficiency

At this point, it is unknown whether it is a nutrient deficiency, yet to be identified toxin or interactions between certain ingredients that are increasing some dogs’ risk of developing DCM. Current research is ongoing to determine the underlying cause of this complex problem. In the meantime, we recommend that you contact your regular veterinarian if you have any concerns about your dog’s health or diet. Particularly if you notice signs of congestive heart failure such as a change in energy level or appetite, a sudden intolerance to exercise or to begins to cough.

For more reliable information regarding pet nutrition, you can visit Dr. Lisa Freeman’s blog at the Tufts University website. Dr. Freeman is a veterinary nutritionist with over 20 years of experience who has been actively involved in the investigation of this issue. You can also read the FDA’s statement on the link between certain diets and canine DCM, which has detailed information on their investigation of the issue.

Written by: Dr. Sadie Griffin, DVM