On Dilated Cardiomyopathy
TLDR; There is no quantifiable connection between diets free of grains and Dilated Cardiomyopathy
Below we summarize our interpretation of the FDA’s timeline on canine dilated cardiomyopathy (DCM). Through this process we have learned a lot about pet food, scientific research on said pet food, and the ever-present influence of big pet food on the science revolving around pet health.
If you are someone who feeds kibble to their dog, you have most likely been exposed to concerns related to the FDA’s statements regarding their investigation into cases of DCM—particularly the information they have released regarding specific kibble formulas and brands they are associating with the disease. We here at Humboldt Pet Supply have followed the case closely as it has developed over the past few years and has been striving to best answer the questions of our concerned customers. The 2018 release by the FDA has prompted quite a surge of concerned kibble-feeders, so we’ve decided to address this multifaceted issue in order to try to make sense of events over the years.
This is an ever evolving article and has been updated several times since 2018.
What we know
While the information released by the FDA in 2018 included information that would be concerning to pet owners who feed their dog’s kibble from the named brands, it is very important that we stress that the information the FDA has published did not constitute a complete and conclusive scientific report. What the FDA had published was the partial data they had collected up to this point. The investigation continued well into 2020. While one can understand the FDA’s motivation to keep the public informed with the latest information regarding this investigation, publishing this half-complete data leaves pet owners with much doubt about the foods they feed their pets while not providing any definitive answers as to what is behind the issue and what to do about it.
One of the most common elements of the FDA’s publishings mentioned by our concerned customers is a particular graph that directly associates specific brands with DCM. This by no means showed that any of the ingredients, formulas, or brands named were the cause of DCM in the reported cases. It only shows that in the reported cases they have examined, these brands were listed as being fed to the dogs. As stated above, the FDA did not find a correlation between the then recent reported DCM cases and is only presenting the data they have collected so far. Now, if you are a concerned kibble-feeder, you would read these graphs and assume that you just need to avoid whatever brands are listed, avoid the ingredients or characteristics of the reported diets, and note the top offending animal proteins and just switch to a different type, all without any sort of conclusive evidence saying what the relationship is between these factors or if any of them are indeed causing DCM.
This presentation of incomplete data really put us, pet owners, in a tough position, because we always want to ensure the health and safety of our dogs. The FDA recommends pet owners work with their veterinarians for advice on their animal’s specific needs before going out and changing their diet. But are vets just defering to this data published by the FDA? In 2023, it is safe to say veterinarians still citing this original data have not kept up to date on the facts of the case and have little interest in understanding this complex issue.
What we See
Throughout the article published, there were many glaring issues with the data collected and presented. The Journal of Animal Science’s Review of canine dilated cardiomyopathy in the wake of diet-associated concerns published in 2020 reveals much of the issues we saw when this paper was originally published. Inconsistencies in the FDA’s statistics, misleading data as a result of sampling bias, and a total lack of accountability for their confounding variables were found throughout. Including the basis of the data, the sample of dogs. Many of which had pre-existing conditions or genetic predispositions to heart issues.
Finishing with:
“At this time, information distributed to the veterinary community and the general public has been abbreviated synopses of case studies, with multiple variables and treatments, incomplete medical information, and conflicting medical data and opinions from veterinary nutrition influencers. Also, in past literature, sampling bias, overrepresentation of subgroups, and confounding variables in the data weaken this hypothesis. Additionally, based on current literature, the incidence of DCM in the overall dog population is estimated to be between 0.5% and 1.3% in the United States. However, the FDA case numbers (560 dogs) are well below the estimated prevalence. Therefore, it is impossible to draw any definitive conclusions, in these cases, linking specific diets or specific ingredients to DCM.”
What to do
If you are concerned and have decided that you indeed want to switch pet foods, we are more than happy to offer some suggestions to help you and your pet transition to a new diet. With the lack of a definitive cause makes it is more difficult to really know what the best course of action is, here at Humboldt Pet Supply, we will always encourage owners to make sure that pets get their most important nutrient, protein, from varying high-quality, animal-based sources. Basing the best nutrition on what they would naturally eat based on biology, not fads, brands, marketing verbiage, or anything else the pet industry may throw at us to convince us of quality. As we will detail below, many of the associated factors in the FDA’s study, such as ingredients in the food, can be circumvented following this philosophy. It is also of note that while the FDA chose to list which brands were reported to be involved in DCM cases, the question is not about which brands to avoid, but rather the ingredients that are commonly used in these grain-free kibbles.
As of publishing this article, the DCM problem is implied to be mostly isolated to kibble diets, many of which rely on peas and lentils as binders or to supplement their protein content. If you are feeding a fresh food diet devoid of both grains and legumes, you do not need to add grains to the diet. The need for peas and lentils as binders is inherently a kibble-specific issue, as the ingredients need to be held together to produce their final shape. In most commercial pet foods, carbohydrates such as grains and starches are used as binders for kibble, while peas and lentils are used as substitutes in these grain-free lines. These binders ultimately end up comprising a large percentage of each kibble unit, leaving less room for animal based ingredients. If you want to avoid the use of peas and lentils as a binder and ensure your pet gets a higher percentage of nutrients, we recommend either switching to foods with higher percentages of meat-based proteins, such as wet foods or raw foods, or at least supplement a kibble-based diet with more high-quality, meat-based protein to ensure your pet is getting the nutrition they need.
The increase in high-quality animal protein in a pet’s diet is highly important because, unlike wet foods and raw diets, kibble can often contain very little animal-based protein. In addition to the binder taking up a large percentage of the food, many kibble manufacturers use vegetable-based proteins as a cost-effective way to increase protein in their foods—proteins like peas and lentils, among others. Vegetable-based proteins are not utilized as effectively by our pets as their meat-based counterparts. This can lead to a myriad of health concerns beyond DCM including obesity, renal failure, diabetes, and more.
The second part of our food recommendation philosophy is to change up your pet’s diet regularly. Much like humans cannot maintain good health by eating the same thing every day, our pets also need a cycle of varying nutrients in order to maximize their health. So in addition to having more of it, varying the type of animal protein your pet eats periodically will make sure they are not lacking any important vitamins or amino acids or, on the flip side, getting too much of one particular vitamin. Of course, every pet is different and their needs vary so there is no one “right” diet that fits every pet. Always feed the pet in front of you, using these as guidelines, not rules.
A third consideration is whether grains belong in diets or not. We have gotten many questions revolving around DCM implying that grains are what keep their hearts healthy. No part of this 4+ year-long scientific process suggested that grains were needed. Merely that ingredients commonly found in “Grain-Free” diets may have been an issue. This has, as of 2020, been reviewed as unsupported and cannot be suggested as a reasoning to the cause of DCM. We go into depth more on this below.
Grains have no biological place in a carnivorous diet. There is no biological requirement for this carbohydrate-heavy food item. The idea that grains would be eaten because they would be found in their prey’s digestive tract, being generous, would only constitute less than 3-5% of their diet. While their inclusion in grain-friendly diets constitutes well over 40% of that diet. Not to mention these grains would be digested or fermented in the prey’s body before consumption, not in the state they are used in kibble. Additionally, most of our dogs or cats’ prey would eat seeds, nuts, grasses, or fruits. Realistically there aren’t any animals that would naturally eat the heavily modified grains we eat today, so why should our pets.
As of September 2020, a multi-organizational group found that dilated cardiomyopathy cannot be attributed solely to diet-related factors. There are too many variables to weigh to consider diet to be a significant part of that. Of course, if one is still concerned about this, the best recommendation is to add more meat-rich taurine to their diet to outweigh the “antinutrients.” These meat items can include shellfish, especially scallops, mussels, and clams. High amounts of taurine can also be found in the dark meat of turkey and chicken, as well as in the heart muscles of most animals.
As of 2022, the University of Missouri veterinarians partnered with a pet care research and consulting firm to evaluate the yearly cases of DCM diagnosis from veterinary cardiologists throughout the United States compared to the nearly exponential increase of “grain-free” food purchases between 2011 and 2019. While “grain-free” food purchase increased by over 500% during this period, there was no significant increase in DCM cases. They concluded that there was no significant correlation between the large increase of grain-free fed diets and the rather minimal increase in DCM cases we are seeing.
As pet owners who feed our own pets some of the same foods mentioned, we have followed the developments as they have happened. We may sell brands that are affected, but don’t let that convince you that we have anything but your pets best interests in mind, because we have our pets interests in mind too. We would never recommend something to your pet that we wouldn’t use with ours. We give serious concern and consideration, using the knowledge we have learned over the many years working in this industry to help guide us through new data like this. We have a Certified Pet Nutritionist on staff as well as a Cal Poly graduate in Biological Sciences to help us all parce through the scientific data and complex nutritional questions at play. This is by no means a write off to take every word we say, but that is why we provide data and research to back up our analysis of the issue. We are not here to convince you, we are here to learn and educate, for your pet’s sake and ours as well.
We have kept up to date on new data and all suggests that there is no connection between “grain-free” diets and dilated cardiomyopathy as hypothesized in 2018 by the FDA. Ultimately, feeding a diet rich in fresh meat will always be the most appropriate diet. All while avoiding starch-rich fillers such as peas, legumes, potatoes, soy, corn, wheat, or any other grain as much as possible. If you are interested in reading the official statements from individual companies regarding DCM, we have printouts available in the dog food room at our store. We have also listed the cited articles below for more in depth reading into this issue. With all this in mind, as of 2022, it is perfectly safe to say this issue is concluded and there is no quantifiable link between diet and DCM. As always we are happy to answer any lingering questions you may have on this complex topic.
Further Reading
2021 update on DCM from the FDA
Pet Food Industry Magazine’s article on updated FDA guidelines in 2020
Kansas State Veterinary Panel - Scientific Forum Exploring Causes of Dilated Cardiomyopathy in Dogs
Original FDA release on DCM in 2019
AMVA - Diet-associated dilated cardiomyopathy in dogs: what do we know? - 2018
