What Is DCM In Dogs And Can Pet Food Cause It?

The U.S. Food and Drug Administration started investigating reports of canine dilated cardiomyopathy (DCM)  last summer, and at the time, linked the heart disease to grain-free dog food.

DCM is an illness that occurs in a dog’s heart muscle when the heart can’t pump blood efficiently due to weak muscle contractions. When this happens, blood doesn’t circulate through the body very well, and over time the heart stretches and enlarges, according to PetMD. Eventually, without intervention, heart failure can occur. Male dogs are more susceptible than females.

On June 27, the regulatory body listed pet food brands that were connected to cases of the illness for the first time.

Brands included Acana, Zignature, Taste of the Wild, Blue Buffalo, Fromm, Merrick, and Orijen. The vast majority of foods mentioned were grain-free and dry kibble, but wet, semi-moist and raw food were also reported, as well as foods with grains.

The FDA emphasized in its DCM update that pet owners shouldn’t rush to change their dog’s food if it is one of the listed brands as they are still testing to find the definitive reason for non-genetic DCM. Instead they should talk to a veterinary nutritionist to obtain the most appropriate dietary advice for their pet’s needs.

“At this time, there is no proof that these ingredients are the cause of DCM in a broader range of dogs, but dog owners should be aware of this alert from the FDA. The FDA continues to work with veterinary cardiologists and veterinary nutritionists to better understand the effect, if any, of grain-free diets on dogs,” Dr. Jerry Klein, the American Kennel Club’s chief veterinary officer, said on the AKC’s website.

Dr. Maggie Brown-Bury, an emergency vet at the Veterinary Speciality Centre of Newfoundland & Labrador and the Canadian Veterinary Medical Association Council’s representative for the province, told HuffPost Canada that pet owners should take a look at the ingredients in the food they’re feeding their dogs even if they’re not from the brands on the FDA list.

“[If] there’s a lot of legumes then you may want to sort of perk up your ears, pay a bit more attention, speak to your veterinarian about whether or not you should be changing your diet or getting your dog assessed for heart disease or a deficiency that might put them at risk for heart disease.”

While many cases of DCM in dogs are genetic and linked to certain breeds — including giant dogs like Doberman Pinschers, Great Danes and Irish Wolfhounds as well as the smaller Cocker Spaniel — the FDA is looking at a small proportion of cases that are linked to a diet with a high proportion of peas, lentils, other legumes and potatoes.

It’s important to note that the FDA looked at 515 reports of canine DCM between 2014 and 2019 and there are 77 million pet dogs in the US, so the vast majority of animals eating grain-free pet food have not encountered any apparent issues.

Still, grain-free foods are not in any way beneficial to dogs that have not been diagnosed with a grain sensitivity or allergy, Dr. Brown-Bury said.

“People that claim that their dog does better since they switched to grain-free… the question should be what was the diet you were feeding before and what are the other differences here?”

She also noted that wild canines also have grains in their diets, contrary to popular belief that they’re exclusively meat-eaters. 

“If you look at like a pack of wolves and they take down a prey, that prey is a plant-eater and they eat the stomach which is full of grain,” she said. “I wouldn’t want a dog to be eating exclusively grains, and meat should definitely be a large part of their diet. But it is not unnatural for them to eat grains.”

Dogs that do require grain-free diets for specific concerns should look for ones that do not have high legume content.

The FDA has not asked the pet food brands listed in the DCM update to recall because it does not yet know what kind of connection the foods have to DCM.

“We do not have definitive information indicating that the food needs to be removed from the market. We have shared case report information with these firms so they can make informed decisions about the marketing and formulation of their products,” the FDA said in their FAQ.

Pet food is not federally regulated in Canada, so the Canadian Food Inspection Agency (CFIA) does not conduct recalls of it.

“The pet food industry has taken the lead in developing quality standards and voluntary compliance programs,” a CFIA spokesperson said via email.

If they’ve developed a deficiency then it may be more than just watching the diet they may benefit from supplements or other interventions to reverse the damage.Dr. Maggie Brown-Bury

The Pet Food Association of Canada (PFAC) said it is looking forward to a complete analysis of the investigation’s data so far. 

“There is no need to panic and any diet change should be made gradually,” PFAC executive director Martha Wilder told HuffPost Canada.

Dr. Brown-Bury also recommended pet owners consult with their vets because even if their dogs show no signs of illness, theTay could be impacted.

“If they’ve developed a deficiency then it may be more than just watching the diet they may benefit from supplements or other interventions to reverse the damage.”

Zignature and Champion Foods — the parent company behind Acana and Orijen — put out statements about the FDA update.

“We remain confident that the pet products created by Zignature’s expert formulation team of veterinarians, PhD animal nutritionists and veterinary research scientists deliver the safest and most nutritious dietary standards available today,” Zignature’s statement said.

“Champion takes seriously our commitment to provide safe pet food that delivers complete and balanced nutrition, and we welcome new information that can help us keep this commitment. In the meantime, we have taken several actions and will continue to do so, which include… two long-term feeding trials with enhanced DCM protocols on two different breeds of dogs – Beagles and Labs,” Champion — which makes all of the food for Canadian consumers in its Alberta kitchen — said in their statement.

Taurine deficiencies

The main theory about the prevalence of non-genetic DCM is that it has to do with the synthesization of the amino acid taurine, which is vital for heart health according to Dr. Brown-Bury. So researchers are investigating if taurine deficiency is causing DCM and if something in pet food — possibly legumes — is blocking taurine creation and/or absorption.

“Our diets have always included taurine through meats and fish in all our products, which is important given that taurine is a meaningful nutrient dogs are sometimes unable to synthesize naturally,” Zignature said.

“In the recipes Champion makes, we emphasize fresh and raw meat with total animal-derived ingredients ranging from 50 to 85 percent of the finished product. Legumes are not a significant feature in Champion’s recipes, and never have been,” Champion noted in their statement.

Choosing new food

Dr. Brown-Bury said the brands listed by the FDA aren’t necessarily worse than others that are grain-free or have legumes, they’re just very popular so “it’s not really a surprise” that they have the most cases. She suggests if owners decide to change their pet’s diet without consulting a vet, they should take a good look at the new food’s bag.

“Their new bag of food should have an AAFCO [Association of American Feed Control Officials] statement on it. So just say something like ‘formulated to meet AAFCO standards’, and that just means that it is nutritionally balanced to have all the nutrients that the dog needs,” she said. 

“The other thing to look at is the ingredient list. Again, looking for those legumes… Ingredients are listed in order of prevalence in the diet by weight. So you see peas or lentils in the first five ingredients, and there’s a lot of legumes in that diet you might want to avoid it until we have more information.”

Signs of DCM include decreased energy, coughing, difficulty breathing and episodes of collapse. If your dog is exhibiting symptoms, they should be taken to a veterinarian as soon as possible. Taurine deficiencies can be reversed, and DCM can be managed with medication if caught early, but heart disease and failure often hit an irreversible stage by the time it is detected.