Grain-free diets and DCM in 2026: what the evidence says

Eight years after FDA first raised concerns, the link between certain diets and canine dilated cardiomyopathy is still not fully explained. We review what the key studies show, what remains open, and what it means for formulators.

PNL

Guires PNL InsightsWritten by the nutrition science and regulatory teams

Reviewed byGuires PNL scientific team

Published10 Sep 2026

Last checked10 Sep 2026

Reading time8 minutes

Key takeaways

FDA has not established that diet causes canine DCM and has issued no public update since December 2022.
The concern centres on diet formulation — especially pulse-rich recipes — rather than the absence of grain alone.
Taurine explains some cases, but not all; the mechanism is still unresolved.
Formulators can manage the risk with pulse limits, amino-acid checks and verified nutrient data.

Bottom line

The evidence shows an association between some non-traditional, pulse-rich diets and DCM in dogs, often improving after a diet change — but not a proven cause. Responsible formulation, not a grain-free ban, is the practical response.

EvidenceModerateRated by the Guires Pet Nutrition Lab scientific team

01Background

In July 2018, FDA announced it was investigating reports of dilated cardiomyopathy (DCM) in dogs eating certain diets, many labelled grain-free and containing high proportions of peas, lentils or potatoes. A June 2019 update named the brands most often reported. In December 2022, FDA said it did not intend to release further public updates until there was meaningful new scientific information to share ¹.

02Key studies

Freeman et al. 2018JAVMA · review

Raised the possible link between DCM and boutique, exotic-ingredient and grain-free (“BEG”) diets, and called for research. ²

Kaplan et al. 2018PLoS ONE · clinical case series

Golden retrievers with taurine deficiency and DCM were eating commercial diets; most improved with diet change and taurine supplementation. ⁵

Adin et al. 2019J Vet Cardiol · retrospective

Echocardiographic findings differed by diet type, and dogs on non-traditional diets showed improvement after a diet change. ³

Smith et al. 2021Sci Rep · foodomics

Compared diets associated with DCM with traditional diets; peas showed the greatest association with the compounds that differed. ⁴

Mornard et al. 2025Vet Sci · narrative review

Legume-rich grain-free diets are linked to often-reversible DCM, and diet change improves survival. ⁷

03Where taurine fits

Taurine deficiency is a proven cause of DCM in cats, reversible with supplementation ⁶. In dogs, some diet-associated DCM cases involve low taurine and respond to supplementation ⁵, but many affected dogs have normal taurine levels. That is why researchers are looking at other factors, including pulse ingredients and the compounds that differ between diets ^4,7.

04What we know — and what we don’t

Reasonably established

An association exists between some non-traditional, pulse-rich diets and DCM in dogs ^2,7.
Many dogs improve after a diet change ^3,7.
Taurine deficiency contributes in some cases ⁵.

Still open

Whether any single ingredient causes DCM.
The biological mechanism behind non-taurine cases.
Why some breeds and individuals are affected and others are not.
Safe inclusion levels for pulses in every format.

05Implications for formulators

Removing grain is not the risk; how the recipe is built may be. A practical, evidence-led approach:

Formulation checklist

Set a documented upper limit for pulse and legume inclusion, and justify it.
Check total sulphur amino acids and taurine precursors against targets, allowing for processing losses.
Use analysed, not book, values for key raw materials.
Verify finished product by laboratory analysis.
Avoid marketing that implies grain-free is healthier without evidence.
Monitor new FDA and peer-reviewed publications and review recipes when evidence changes.

Guires Pet Nutrition Lab verdict

The association is real but the cause is not proven. Formulate responsibly — pulse limits, amino-acid checks, analysed data — rather than avoiding grain-free altogether.

06Questions brands ask

Is grain-free food unsafe?

FDA has not established that diet causes canine DCM. The concern relates to how some pulse-rich recipes are formulated, not the absence of grain alone.

Does adding taurine solve the problem?

Taurine explains some cases, but many affected dogs had normal taurine levels, so it is not a complete answer.

Sources

FDA. FDA investigation into potential link between certain diets and canine dilated cardiomyopathy. Source ↗
Freeman LM et al. (2018). Diet-associated dilated cardiomyopathy in dogs: what do we know? JAVMA 253(11):1390–1394. Source ↗
Adin D et al. (2019). Echocardiographic phenotype of canine dilated cardiomyopathy differs based on diet type. J Vet Cardiol 21:1–9. Source ↗
Smith CE et al. (2021). Investigation of diets associated with dilated cardiomyopathy in dogs using foodomics analysis. Sci Rep 11:15881. Source ↗
Kaplan JL et al. (2018). Taurine-deficient dilated cardiomyopathy in golden retrievers fed commercial diets. PLoS ONE. Source ↗
Pion PD et al. (1987). Myocardial failure in cats associated with low plasma taurine. Science. Source ↗
Mornard L et al. (2025). Role of diet as a predisposing factor for dilated cardiomyopathy in dogs: a narrative review. Vet Sci 12(11):1106. Source ↗

Evidence reviewed by the Guires Pet Nutrition Lab scientific team. This article is general information for product developers and is not legal or veterinary advice.

How to cite this article

Choose your referencing style, then copy. Check your university’s, journal’s or regulator’s guide for local variations.

Guires Pet Nutrition Lab. (2026, September 10). Grain-free diets and DCM in 2026: what the evidence says. Guires Pet Nutrition Lab Insights. https://www.petnutritionlab.com/insights/grain-free-dcm-evidence

This article summarises published evidence for product developers. Cite the original sources above for specific findings, and do not reproduce this article as your own work.

Building a grain-free or pulse-rich recipe?

We set evidence-based inclusion limits and verify amino-acid adequacy before launch.

See how we help →Talk to a Scientist