Updates on nutritional dilated cardiomyopathy in dogs
Where are we as of February 2025?
What is DCM?
DCM stands for dilated cardiomyopathy. This is a disease in which the ventricles of the heart dilate, leading to difficulty for the heart to do its job in pumping blood. Symptoms develop because the body is not receiving enough oxygenated blood, or because of congestion of blood in the lungs – or both.
Clinical signs include weakness, lethargy, weight loss, collapse, trouble breathing, cough, increased respiratory rate/effort, abdominal distension, or sudden death. They can also have cardiac arrythmias secondary to the damage to the wall of the heart.
Diagnosis of DCM is typically done via echocardiogram, or ultrasound of the heart. X-rays can show an enlarged heart. A Holter monitor may be placed to monitor for any arrythmias.
Treatment involves medications to improve the ability of the heart to pump, as well as dilating peripheral blood vessels to decreased workload and getting rid of fluid in the lungs if present. DCM is not curable, and is typically seen in certain breeds.
How is nDMC different?
NDCM (also sometime referred to as ‘atypical’ DCM or aDCM) is caused by nutritional deficiencies or abnormalities leading to DCM. NDCM has been shown to be reversible in some cases with diet change, as well as medication.
History of nDCM
Mid 2010’s
Veterinary cardiologist and veterinarians note an uptick in DCM in breeds that aren’t typical for the disease. The FDA begins collecting data in 2014
2018
The FDA makes a wider announcement, encouraging veterinarians to report any cases of suspect nDCM
December 2018
A prospective study is released where 24 Golden Retrievers with DCM and taurine deficiency were evaluated. 23 of the 24 were fed either a grain free, legume-rich or a combination of these. None of these diets were feed trial tested. 23 of the 24 dogs had improvement in echo and normal taurine concentrations following diet change and taurine supplementation. 9/11 dogs diagnosed with CHF had resolution of congestion and 5 no longer needed diuretics.
This started the deep dive into taurine deficiency as the mechanism for nDCM. We know taurine deficiency can lead to DCM – in the late 1980’s there was a concerted effort to determine why so many cats had DCM. It was found that taurine deficiency was the culprit. Supplementation of taurine saw improvement in many of these cases, though those too affected still died.
2019
June 2019
The FDA issues its first update, revealing 515 dogs had been reported. They created a list of the breeds, brands and ingredients within the report, as well as a PDF of all complaints. The common denominator “BEG” diets (Boutique, exotic and grain free). “Grain free” diets, which had high proportions of peas, lentils or other legumes (pulses) and potatoes. “Boutique,” meaning they were made by smaller manufactuers and did not have boarded nutritionists or meet WSAVA guidelines. “Exotic,” meaning the main meat ingredient was an exotic protein, like kangaroo. Despite this, no obvious mechanism or cause was noted.
2019-2020 and lobbying
Farmers and pulse growers associations began to talk about the impact this would have on their sales. About 10-20% of pulse crops go to pet food. This includes a newsletter from the Northern Pulse Growers Association and their efforts to urge the FDA to stop giving updates. In May the “Pulse Pipeline” announced they were donating to BSM Partners, a pet formulation group. Their goal?
"BSM is asking for $5 million to conduct three important research projects that have the potential to discover the true cause of DCM in dogs and take the heat off of grain-free diet ingredients."
June 2020
BSM releases its first literature review, claiming they analyzed 150+ studies and saw no link between diet and DCM. This was immediately dismissed by sources such as VIN and the Canine Review.
As we move through 2020, we see more efforts from grain and pulse producers to silence the FDA. Columbia Grain International announced a $25,000 donation to BSM Partners. In September seven senators write to the FDA , urging them to be impartial
“We are asking for your assurance the FDA will ensure the symposium is organized in an objective manner, and that the best available science is made available and examined, so as to prevent any bias about causation of this disease.”
Plus some comments about stakeholders wanting the underlying medical records.
The symposium in question? The Kansas State University symposium, with the FDA as well as industry, who gave presentations on diet-associated DCM. This is where the FDA admitted to 1,100 filed complaints. It also included a presentation detailing recovery in cases that had undergone diet changes.
December 2020
An observational, retrospective study showed that changing a dogs diet from eating non-traditional food to a traditional food was associated with a significant increase in mean survival time, and reversal in some patients!
2021
As we get into 2021, several more studies are released, showing everything from higher levels of Cardiac Troponin I on grain free diets, to length of time on a grain free diet associated with worse outcomes.
Still, the exact mechanism is unknown. A “Foodomics” research out of Tufts in August of 2021 shed light on the possible underlying etiology. Unique, unnamed compounds were found in diets with >3 pulses, not found in other diets. These diets also had nutrient deficiencies and excesses, with peas being a big culprit.
2022
March 2022
BSM releases a survey study, tracking the incidence of DCM vs. rise in sales of grain free diet. As with their first release, this is met with a ton of backlash. They collected responses from 14 hospitals, ignoring major referral centers or places that were recruiting nDCM cases. The media ate it up, reporting “no link between the two.”
As 2022 continues on, multiple studies are published, showing improvement in biomarkers when switched from a grain-free to a grain-inclusive diet, that feeding a pulse-legume rich exotic protein diet was associated with decreased RBC and increased serum phosphorus.
December 2022
The FDA quietly updates their nDCM page on 12/23 with additional data showing the cumulative number of reports of nDCM at 1,382. They also create a statement that is misrepresented across media –
“The FDA does not intend to release further public updates until there is meaningful new scientific information to share.” And “While adverse event numbers can be a potential signal of an issue with an FDA regulated product, by themselves, they do not supply sufficient data to establish a casual relationship with reported product(s).”
The media amplifies the message – even the AVMA! (in a now updated post) – that claims the FDA said no relationship noted.
That same month, a study compared echocardiographic measurements and cardiac biomarkers between healthy dogs eating notradition vs traditional diets. Healthy dogs on nontraditional diets had lower indices of systolic function and larger left ventricular volumes.
2023
Feb 2023
Major study investigated nDCM in cats fed high and low pulse diets and doesn’t find a significant association with cardiac size, function and biomarkers (but does note the high-pulse groups were more like to be overweight).
Feb 3rd 2023
FOIA request was filed by Susan Thixton at Truth About Pet Foods from the FDA
April 2023
Emily Brill at The Canine Review files a FOIA for the DCM cases. Caitlin Holly used that information to create some excellent charts here.
May 2023
A study funded by Champion in Siberian Huskies claimed no changes in BNP or echocardiograph parameters in dogs fed a high pulse diet for 20 weeks. It’s important to note that the diets used only included up to 15% pulses, and previous studies have shown peas and lentils as the biggest offenders.
May 2023
BSM releases a study showing beagles fed high-pea, high-amylose diets developed DCM-like changes on echo after only 28 days of feeding.
June 2023
US Gov releases a bill that states
Canine Dilated Cardiomyopathy.
--The Committee encourages FDA to refrain from issuing statements, bulletins, or advisories linking canine dilated cardiomyopathy to certain pet food ingredients unless new information is available, such as completion of adequate, peer-reviewed scientific studies or publication of the proceedings from a scientific meeting or colloquium.
July 2023
Pitbulls with DCM had improved echo findings after switching to a traditional diet.
October 2023
BSM releases another study of 55 dogs –
“The diet groups were as follows: the high-animal-protein grain-free (HAGF) group, the low-animal-protein grain-free (LAGF) group, the high-animal-protein grain-inclusive (HAGI), and the low-animal-protein grain-inclusive (LAGI) group. Cardiac-specific biomarkers, endomyocardial biopsies, and linear and volumetric echocardiographic parameters were evaluated.”
In the end, no cardiac dysfunction parameters were measured. However, they admit several limitations in the study, including increased sympathetic tone during exam, hydration status, sampling only the right ventricle and not the left, and not using echocardiographic parameters such as E-point-to-septal separation and sphericity index.
2024
February 2024
A company called Ketonatural files a lawsuit against Hills and several nDCM researchers, purporting they used a shadow network of veterinarians to advise against feeding anything but Hills.
May 2024
97 Irish Wolfhounds undergoing routine echocardiograms at dog shows between Oct 2018-May 2021. 17% of high-pulse diet dogs had VPCs vs. low pulse diet group (2%)
October 2024
Dogs with nDCM have electron microscopic changes suggestive of abnormal lysosoam accumulation of phospholipids, consistent with the appearance of drug-induced phospholipodosis in people and other animals. This supports the possible presence of a primary or secondary phospholipidosis in dogs with nDCM.
November 2024
Ketonatural lawsuit is dismissed
Where are we now?
At this point, there’s likely a myriad of causes coming together to create this problem. If we compare breeds from the FOIA, you’ll see Goldens and Labs at the top of the list, with mix breed up there as well. This begs the question - are certain breeds more sensitive to this disease? Or are these just the most popular breeds in the US, hence their overrepresentation?
Certain diets continue to land at the top of the list of implicated diets. Pulse legumes, like peas, lentils and chickpeas, have been implicated the highest in these diets.
What about grain inclusive diets that have peas, lentils or chickpeas in them? I’ll share the recommendations from UC Davis >
“While avoiding all suspect ingredients may be the most direct way to select a new diet, we suggest that a small amount of legume content in a well-formulated grain-inclusive diet may be OK. Our guidelines allow for no more than two legume ingredients in a grain-inclusive diet when found low on the ingredient list (below all meat and grain content). Importantly, these diets should still be tested by AAFCO feeding trial.”
There are diets high in pulses that were not correlated with nDCM cases. These tended to be amongst brands with feeding trials, or brands that are WSAVA compliant. This like means there’s a formulation component to the development of these cases.
Owners should utilize Pet Nutrition Alliance’s “Right to Know” information to assess if their food is WSAVA compliant or not.
And - as always - you should speak with your veterinarian about your pet to determine the best diet for them!
Favorite Resources
-All Trades DVM (Dr. Holly has timelines, Q+As and does great break downs of each of these studies in WAY more detail!)
-Petfoodology from Tufts (Tufts is one of the leading centers for animal nutrition and has so many amazing articles!)
-Diet Associated Dilated Cardiomyopathy Facebook group (The moderators of this group have so many resources for pet owners, veterinary professionals and host Q+As !)
Sources
-2020.09.11 FDA DCM Letter.pdf | Powered by box. (n.d.). https://senatorkevincramer.app.box.com/s/jik4ggjno2rn9n2qagnbd8n83flf85rl
-Adin, D., et al (2021). Effect of type of diet on blood and plasma taurine concentrations, cardiac biomarkers, and echocardiograms in 4 dog breeds. Journal of Veterinary Internal Medicine, 35(2), 771–779.
-AllTradesDVM - DCM FDA Data Update 2023. (n.d.). https://www.alltradesdvm.com/topics/diet-associated-dcm/dcm-articles/dcm-fda-data-update-2023
-Bakke, A. M., et al (2022). Responses in randomised groups of healthy, adult Labrador retrievers fed grain-free diets with high legume inclusion for 30 days display commonalities with dogs with suspected dilated cardiomyopathy. BMC Veterinary Research, 18(1).
-Brill, E., (2024, February 15). Exclusive: FDA releases hundreds of dog DCM case reports via FOIA. The Canine Review. https://thecaninereview.com/2023/04/25/exclusive-fda-releases-84-pages-of-diet-dcm-case-details/
-Center for Veterinary Medicine. (2022, December 23). FDA Investigation into Potential Link between Certain Diets and Canine Dilated Cardiomyopathy. U.S. Food And Drug Administration. https://www.fda.gov/animal-veterinary/outbreaks-and-advisories/fda-investigation-potential-link-between-certain-diets-and-canine-dilated-cardiomyopathy
-CGI donates >5K to DCM research fund campaign. (n.d.). PetfoodIndustry. https://www.petfoodindustry.com/news-newsletters/pet-food-press-releases/press-release/15467006/cgi-donates-25k-to-dcm-research-fund-campaign
-Coppinger, L. et al (2024). Echocardiographic and electrocardiographic findings in Irish Wolfhounds eating high‐pulse or low‐pulse diets. Journal of Veterinary Internal Medicine, 38(3), 1300–1304.
-FDA Center for Veterinary Medicine. (2020). FDA update on dilated cardiomyopathy: Fully and partially recovered cases. In Kansas State University’s Scientific Forum Exploring Causes of Dilated Cardiomyopathy in Dogs. https://ksvdl.org/resources/documents/dcm-forum/FDA_KSU-Science-Forum-slides_09-29-2020.pdf
Fischer, K. et al (2023). Pit bull–type breeds with dilated cardiomyopathy eating nontraditional diets improve after diet change (2015–2022). Journal of the American Veterinary Medical Association, 261(7), 1011–1019.
-Freeman, L. et al (2024). Dogs with diet-associated dilated cardiomyopathy have higher urine di-docosahexaenoyl (22:6)-bis(monoacylglycerol)phosphate, a biomarker of phospholipidosis. American Journal of Veterinary Research, 1–6.
-Freid, K. J., et al. (2020). Retrospective study of dilated cardiomyopathy in dogs. Journal of Veterinary Internal Medicine, 35(1), 58–67.
-Haimovitz, D., et al. (2022). Effect of diet change in healthy dogs with subclinical cardiac biomarker or echocardiographic abnormalities. Journal of Veterinary Internal Medicine, 36(3), 1057–1065.
-Kaplan, J. L., et al. (2018). Taurine deficiency and dilated cardiomyopathy in golden retrievers fed commercial diets. PLoS ONE, 13(12), e0209112.
-Karp, S. I., et al. (2023). Comparison of echocardiography, biomarkers and taurine concentrations in cats eating high- or low-pulse diets. Journal of Feline Medicine and Surgery, 25(2).
-Leach, S. B., et al. (2023). Prospective evaluation of echocardiographic parameters and cardiac biomarkers in healthy dogs eating four custom-formulated diets. Frontiers in Animal Science, 4.
-McCauley, et al. (2020). Review of canine dilated cardiomyopathy in the wake of diet-associated concerns. Journal of Animal Science, 98(6).
-Owens, E. J., et al. (2022). Comparison of echocardiographic measurements and cardiac biomarkers in healthy dogs eating nontraditional or traditional diets. Journal of Veterinary Internal Medicine, 37(1), 37–46.
Paper downplaying risk to dogs of grain-free diets draws fire. (n.d.). https://news.vin.com/default.aspx?pid=210&Id=9721899
-Pion, P. D., et al (1987). Myocardial Failure in Cats Associated with Low Plasma Taurine: a Reversible Cardiomyopathy. Science, 237(4816), 764–768.
-Quest, B. et al (2022). Incidence of canine dilated cardiomyopathy diagnosed at referral institutes and Grain-Free pet food store Sales: A Retrospective survey. Frontiers in Animal Science, 3.
-Quilliam, C., et al. (2023). Effects of a 28-day feeding trial of grain-containing versus pulse-based diets on cardiac function, taurine levels and digestibility in domestic dogs. PLoS ONE, 18(5), e0285381.
-Singh, P., et al. (2023). The Pulse of It: Dietary Inclusion of Up to 45% Whole Pulse Ingredients with Chicken Meal and Pea Starch in a Complete and Balanced Diet Does Not Affect Cardiac Function, Fasted Sulfur Amino Acid Status, or Other Gross Measures of Health in Adult Dogs. Journal of Nutrition, 153(5), 1461–1475.
-Pet food adverse event reports submitted to FDA. https://truthaboutpetfood.com/pet-food-adverse-event-reports-submitted-to-fda/
-Walker, A., et al (2021). Association of diet with clinical outcomes in dogs with dilated cardiomyopathy and congestive heart failure. Journal of Veterinary Cardiology, 40, 99–109.