If you feed your dog a grain-free diet, you’ve probably heard about the potential link between grain-free dog foods and a condition called canine dilated cardiomyopathy (DCM). And if not…well, listen up, because it’s something that needs to be on your radar.
Here’s the scoop. In June, the Food and Drug Administration (FDA) announced it was looking into a potential connection between grain-free diets and DCM. Dilated cardiomyopathy is no joke…it’s a serious heart condition in which the heart’s ventricles become enlarged and gradually lose their ability to pump blood, and can lead to full-blown heart failure.
The announcement was shocking, to say the least. Many people believe grain-free food is healthier for dogs than kibble filled with wheat, cornmeal, rice, or barley – it tends to be made with higher quality ingredients and with more protein, which means less risk of weight gain from excess carbs. And over the last decade, we’ve seen the popularity of grain-free dog food skyrocket. According to the New York Times, grain-free dog food started gaining traction after a series of recalls of pet food from China; by the end of 2017, it accounted for 44% of pet food sales. So when the FDA announced a link between grain-free dog food and cardiomyopathy, well-intentioned grain-free feeders everywhere were left wondering what foods are safe to feed their furry family members every day?
At this point we don’t know what it is about grain-free diets that may be causing DCM, but the fact that it’s gotten the FDA’s attention is alarming. To help you get a better handle on the situation and feel confident you’re doing everything you can to help support your pet’s health, I spoke with two veterinarians to get their take. Here’s what they had to say…
Grain-Free Diets May Be Linked to Taurine Deficiency
One theory that seems to be getting traction is the idea that either the lack of grains in grain-free foods or the ingredients used as a substitute – usually peas, lentils, legumes, and various forms of potato – are causing dogs to develop a deficiency in the amino acid taurine. Dogs produce taurine naturally, so one thought is that the substitute ingredients may be interfering with a dog’s ability to produce it. Another is that without grains, dogs aren’t able to make enough of it and may eventually develop a deficiency.
This is important because taurine deficiency has been independently associated with DCM. There also is a study in which dogs with DCM showed some improvement after being fed diets supplemented with taurine. Unfortunately, though, both studies have limitations – but they do provide some direction as to where to begin research.
This possibility also squares with my experience treating people, in the sense that whenever you completely eliminate a certain type of food from your diet, you have to be aware of unintended consequences. Take vegans and vegetarians, for example. One of the best sources of coenzyme Q10 (CoQ10) – an essential nutrient for human heart health – is meat. I always advised patients who followed these diets to make sure they found other sources of CoQ10 to offset the loss.
Grain-Free Diets May Not Be as Healthy as Billed
Another recurring theme I heard was that grain-free diets for dogs simply aren’t all they’re cracked up to be, to begin with.
A lot of grain-free food manufacturers market their products by claiming that grain-free is “more natural,” because dogs in the wild don’t usually eat grains like wheat, rice, oats, corn, and barley. While this is good marketing, it’s not necessarily true, according to one veterinarian I consulted with – Emily Wilkinson, DVM.
Dr. Wilkinson reminded me that dogs in the wild (and their wolf ancestors) eat differently than the dogs that live with us. When dogs in the wild eat their prey, they eat all of it – including the animal’s vital organs, bones, and stomach contents. Since the prey animals eat mostly plants, a wild dog would be consuming them as well. So the claim that dogs have never eaten grains and are not equipped to eat grains would stretch the truth somewhat, if prey animals are indeed eating wheat, cornmeal, barley or rice. It also overlooks the fact that domesticated dogs have developed genes specific to carbohydrate digestion, so it’s not an exact comparison.
That said, I know a lot of you may still be concerned about feeding your dog a grain-based diet. I’d compromise here and look for ways to cut back on grains, but not necessarily eliminate them entirely – at least until we know more about what’s happening around the DCM issue. For example, give foods that contain higher quality grains, but look for treats that are grain-free.
Peas, Lentils and Potatoes as Main Ingredients
The DCM problem seems to be related only to foods in which peas, lentils, legumes, and/or potatoes are a main ingredient – that is, they should be listed in the top 10 ingredients on the label. Through its investigation, the FDA learned that, in 93 percent of the 515 reported canine DCM cases, peas or lentils were a main ingredient; peas were implicated in 89 percent of the cases, and lentils in 62 percent. Potatoes or sweet potatoes also were at play in 42 percent of the cases.
The takeaway here is that foods that replace grains with peas, lentils or potatoes as main ingredients should be avoided. Smaller amounts of these ingredients aren’t under suspicion, so there’s no need to worry if those ingredients are part of your pet’s food, so long as they’re way down the list.
The DCM Problem May Be Bigger Than Reported
Many grain-free food manufacturers have responded to this is by calling out the numbers. They say that too few dogs have been affected to make sweeping judgments, and that those who have been affected are disproportionately large breed dogs genetically prone to the disease.
Officially, the FDA received 515 reports of canine DCM from January 1, 2014 and April 30, 2019; of those, 219 occurred in just five months, from December 2018 through April 2019. I’ll admit that this is miniscule sample when you consider that there’s estimated to be 77 million household dogs, with 30-ish million eating grain-free diets. However, one of my veterinary sources says you should take it with a grain of salt.
She tells me that whenever she detects a potential heart problem in a dog, she always refers those animals to a “canine cardiologist” for further evaluation and diagnosis. Unfortunately, many of them never take that next step because many pet parents simply can’t afford the cost of seeing a specialist. (Some things are the same, whether human or animal!) This leads her to believe that the problem may actually be underreported. FDA agrees with this, writing, “We suspect that cases are underreported because animals are typically treated symptomatically, and diagnostic testing and treatment can be complex and costly to owners.”
What Should You Do?
It’s a difficult call, given how little we know at this point, but your dog’s heart – just like your heart – isn’t an organ you want to take chances with. I’d err on the side of caution and, at a minimum, stop feeding your dog foods where peas, lentils or potatoes are main ingredients.
If you’ve been feeding grain-free, do your best to document your dog’s diet history. That way if you end up in a worst-case scenario (heaven forbid), you’ll have plenty of information to share with your veterinarian.
Next, get familiar with the signs of canine dilated cardiomyopathy. Call your vet right away if your dog begins to show any of the following:
- Labored or rapid breathing
- Abdominal distention
Other Ways to Protect Your Dog’s Heart
More generally speaking, here are a couple more easy ways you can help keep your dog’s heart healthy:
Make sure your dog maintains a healthy weight and gets plenty of exercise. Why? Both go a long way toward keeping blood pressure in check. In people, high blood pressure is a major reason why hearts become enlarged and begin to fail.
Supplement your dog’s diet with CoQ10. Even though CoQ10 hasn’t been associated with DCM, I find it an incredibly valuable tool for treating human heart disease. CoQ10 is essential to the body’s ability to produce and use energy – and no organ requires more energy than the heart. In a heart that’s weakened, CoQ10 can provide an energy boost and help the heart pump more efficiently. It won’t restore the heart to a normal size, but it did improve the quality of life for many of my patients.
To get more CoQ10 in your dogs’ diets, feed them organ meats, fatty fish like salmon or sardines, or muscle meats – these are the best food sources of CoQ10. If you’re squeamish or don’t want the hassle of cooking for your dog, try freeze dried pet treats made with these meats or fish.
Or you can give your dog more concentrated doses with a CoQ10 supplement. The easiest and best way to give CoQ10 is in liposomal drops. For healthy dogs, the dosage specified on the label (based on body weight) will provide the needed support. If your dog’s heart is compromised in some way, you’ll want to double the dose for the first two weeks, then switch to the suggested dosage amount.
- Cornell University College of Veterinary Medicine. Canine Dilated Cardiomyopathy. Accessed August 26, 2019.
- Food and Drug Administration. FDA Investigation Into Potential Link Between Certain Diets and Canine Dilated Cardiomyopathy. 27 Jun 2019.
- Hoffman J. Popular Grain-Free Dog Foods May Be Linked to Heart Disease. NY Times, July 24, 2018/
- Kaplan JL, et al. Taurine deficiency and dilated cardiomyopathy in golden retrievers fed commercial diets. PLoS One. 2018 Dec 13;13(12):e0209112.
- Pennisi E. Diet Shaped Dog Domestication. Sciencemag.org, Jan. 23, 2013.
- Adin D, et al. Echocardiographic Phenotype of Canine Dilated Cardiomyopathy Differs Based on Diet Type. Journal of Veterinary Cardiology. 2019 Feb;1-9.
- Freeman LM, et al. Diet-associated Cardiomyopathy in Dogs: What Do We Know? Journal of the American Veterinary Medical Association. 1 Dec 2018;253(11):1390-1394.
- Axelsson E, et al. The Genomic Signature of a Dog Reveals Adaptation to a Starch-Rich Diet. Nature. 21 Mar 2013;495:360–364. [https://www.nature.com/articles/nature11837]
© 2019 Stephen Sinatra, MD. All rights reserved.