Grain-Free Dog Food Investigation
LAWSUITS ALLEGE POPULAR GRAIN-FREE DOG FOODS ARE LINKED TO A FATAL HEART DISEASE and related cardiac damage — AND THAT MANUFACTURERS KNEW
Stueve Siegel Hanson, Shank & Heinemann LLC, and Schirger Feierabend LLC are investigating claims that grain-free, high-legume dog foods increase the risk of canine dilated cardiomyopathy ("DCM"), a serious and often fatal heart disease, as well as related cardiac damage, and that the companies making and selling these products failed to disclose this risk.
Our firms are taking these cases to court. We represent a certified class of Missouri consumers, with trial set for January 8, 2027, against the maker of Taste of the Wild grain-free dog food. We have also filed a proposed class action on behalf of California purchasers of Taste of the Wild grain-free dog food and a proposed nationwide class action against Costco over its Kirkland Signature Nature's Domain grain-free dog food.
If you purchased grain-free dog food, or if your dog was diagnosed with DCM or suffered other cardiac damage, or died unexpectedly while eating a grain-free diet, we want to hear from you. Contact us for a free, confidential case evaluation.
Already a member of the Missouri Taste of the Wild class?
If you purchased Taste of the Wild grain-free dog food in Missouri between August 27, 2015, and June 21, 2024, you are likely already a member of the certified class in Harmon v. Schell & Kampeter, Inc. — and you do not need to do anything to be included. For case documents, deadlines, and answers specific to that class, visit the official case website: missouridogfoodclassaction.com or call the Notice Administrator at 1-866-502-7826.
Current Status of the Litigation
Trial set for January 8, 2027 — Jackson County, Missouri. Stueve Siegel Hanson, Shank & Heinemann LLC, and Schirger Feierabend LLC represent a certified class of Missouri consumers in Mary Harmon and Connie Curts v. Schell & Kampeter, Inc. d/b/a Diamond Pet Foods and/or Taste of the Wild, Case No. 2016-CV17833, in the Circuit Court of Jackson County, Missouri at Independence, Division 5.
The class action alleges that Taste of the Wild grain-free dog food, sold by Schell & Kampeter, Inc. (doing business as Diamond Pet Foods), was falsely and deceptively marketed as high-quality, safe, and healthy for dogs. The lawsuit claims this deceptive marketing violates the Missouri Merchandising Practices Act, a statute designed to protect consumers from misleading business practices, and asserts a claim for unjust enrichment. The class has been certified, notice has been issued, and the case is set for trial.
April 29, 2026 — A separate proposed class action, Vilekar v. Schell & Kampeter, Inc., No. 4:26-cv-03723 (N.D. Cal.), was filed by Stueve Siegel Hanson, Girard Sharp LLP, Shank & Heinemann LLC, and Schirger Feierabend LLC, against the maker of Taste of the Wild grain-free dog food raising substantially similar allegations in the U.S. District Court for the Northern District of California.
June 23, 2026 — Stueve Siegel Hanson, together with Tousley Brain Stephens PLLC, Shank & Heinemann LLC, and Schirger Feierabend LLC, filed a proposed class action against Costco Wholesale Corporation in the U.S. District Court for the Western District of Washington. The case, West v. Costco Wholesale Corp., No. 2:26-cv-02182, alleges that Costco misleadingly marketed its Kirkland Signature Nature's Domain grain-free dog food as healthy and safe without disclosing its association with DCM.
Our investigation is ongoing and is not limited to these brands.
What Is Dilated Cardiomyopathy (DCM)?
DCM is a potentially fatal condition in which the heart's left ventricle becomes enlarged and weakened, and the heart loses its ability to pump blood effectively. It is the second most common heart disease in dogs overall and the most common in large breeds.
Historically, DCM was understood as an inherited, genetic disease affecting only predisposed breeds — Doberman Pinschers, Great Danes, Irish Wolfhounds and other large breeds. Over time, however, veterinary researchers began documenting a second pathway: diet-associated DCM, in which the disease develops in dogs with no genetic predisposition at all.
A growing body of scientific research demonstrates a causal association between grain-free, high-legume diets and canine cardiac damage, including DCM, in both predisposed and non-predisposed breeds.
One of the most significant features of diet-associated DCM is that, unlike the genetic form, it can improve — and in some documented cases fully reverse — when the dog's diet is changed. Some dogs have even been able to discontinue cardiac medications after switching off a grain-free diet.
Why the "occult" phase matters
DCM progresses in stages. The preclinical or "occult" phase can last several years, and during that time a dog may show no outward symptoms at all while cardiac damage accumulates. Many owners never learn their dog's heart has been affected until the dog is diagnosed with advanced disease — or dies suddenly.
Warning Signs Dog Owners Should Know
Contact your veterinarian if your dog shows any of the following:
- Difficulty breathing or respiratory distress
- Exercise intolerance, weakness, or lethargy
- Coughing
- Fainting or collapse (syncope)
- Abdominal swelling or distension (ascites)
- Weight loss or reduced appetite
- Sudden collapse or unexplained death
This page is not medical advice. If you are concerned about your dog's health, talk to your veterinarian. Veterinary cardiologists can screen for cardiac changes with an echocardiogram and bloodwork measuring cardiac biomarkers such as NT-proBNP and cardiac troponin-I.
What the Lawsuits Allege
The complaints filed to date allege, among other things:
There is no medical reason for most dogs to eat a grain-free diet. Fewer than 1% of dogs have food allergies or sensitivities, and among that small group, grain allergies are rarely the cause. The lawsuits allege grain-free diets became popular not because of canine nutrition science but as a marketing response to human diet trends like Atkins, gluten-free, and paleo.
Legumes replaced grains — at scale, and cheaply. When grains are removed from kibble, manufacturers need another carbohydrate source to make the extrusion process work. Peas, lentils, chickpeas, pea flour and pea protein filled that role, often in far higher concentrations than had ever been used in pet food, and at a lower cost than animal protein.
The science accumulated, and the industry knew. By 2018, veterinary researchers were publishing studies in peer-reviewed journals linking grain-free, high-legume diets to elevated cardiac biomarkers, increased left ventricular internal diameter, and DCM. Veterinary textbooks now identify diet-associated DCM as a differential diagnosis and recommend immediately switching affected dogs off grain-free food.
No feeding studies were conducted. The complaints allege that defendants brought these novel formulations to market — and have kept them there — without conducting or publicly disclosing any feeding study assessing cardiac safety.
Consumers were never told. The complaints allege that nowhere on the packaging are consumers informed of the association between grain-free dog food and cardiac damage.
Consumers paid a premium for it. Dog owners paid more for products marketed as premium, natural, and healthy — a price premium the lawsuits allege was obtained through misrepresentation and omission.
THE FDA INVESTIGATION
In July 2018, the FDA opened an investigation into reports of DCM in dogs eating pet foods containing peas, lentils and other legume seeds as main ingredients — most commonly foods labeled "grain-free."
By its June 2019 update, the FDA had received 524 DCM reports involving 574 animals, including 124 deaths. The FDA identified the brands most frequently named in those reports:
| Brand | Reports naming the brand |
|---|---|
| Acana | 67 |
| Zignature | 64 |
| Taste of the Wild | 53 |
| 4Health | 32 |
| Earthborn Holistic | 32 |
| Blue Buffalo | 31 |
| Nature's Domain | 29 |
| Fromm | 24 |
| Merrick | 16 |
| California Natural | 15 |
| Natural Balance | 15 |
The FDA noted the reported cases “involve a wide range of dog breeds, ages and weights.” In December 2022, after intense lobbying from companies selling grain-free dog food and other industry interests, the agency announced it would not release further public updates until it deems there is meaningful new scientific information to share. The complaints allege that pet food industry pressure contributed to that decision, and that the absence of further FDA updates has been misrepresented to consumers as a clean bill of health.
Source: FDA Investigation into Potential Link between Certain Diets and Canine Dilated Cardiomyopathy
Which Products Are Involved?
Our investigation covers grain-free dog foods that contain legume or pulse ingredients — peas, lentils, chickpeas, pea flour, pea protein and similar ingredients — among the first ten ingredients listed on the label. This includes, but is not limited to:
- Kirkland Signature Nature's Domain (Costco) — Salmon & Sweet Potato, Beef & Sweet Potato, Turkey & Sweet Potato, Puppy Chicken & Pea, Small Breed Salmon & Lentils, and Turkey & Pea Stew
- Taste of the Wild grain-free recipes, sold by Schell & Kampeter, Inc. d/b/a Diamond Pet Foods — including High Prairie, Pacific Stream, Sierra Mountain, Southwest Canyon, Wetlands, Pine Forest, Appalachian Valley, and the Prey limited-ingredient line sold at major pet specialty retailers like Petco, Hollywood Feed, and Pet Supplies Plus, as well as farm and hardware stores like Tractor Supply Company and Ace Hardware
- WholeHearted grain-free recipes sold by Petco and available at Petco, Amazon, and Lowe's.
- Acana grain-free recipes sold by Champion Petfoods and sold at Chewy, Petco, Pet Supplies Plus, Amazon and other specialty pet food shops.
- Blue Buffalo grain-free recipes sold by General Mills and sold at major pet supply stores like PetSmart, Petco, online retailers including Chewy and Amazon, and big-box stores like Walmart.
- Zignature, 4Health, Earthborn Holistic, Fromm, Merrick, Natural Balance and other grain-free, high-legume formulas sold at the various suppliers listed above.
Not sure whether the food you bought qualifies? Check the ingredient panel — if the label says "grain-free" and peas, lentils, chickpeas or their derivatives appear in the first ten ingredients, contact us and we can help you determine whether you may be eligible.
Who May Be Affected
You may be able to participate in this investigation if either of the following applies:
- You purchased grain-free dog food. The filed cases assert consumer-protection claims on behalf of purchasers who allege they paid a premium for a product marketed as safe and healthy without disclosure of its cardiac risk. You do not need to have a sick dog to be part of a consumer claim.
- Your dog was diagnosed with DCM or other heart damage, or died unexpectedly, while eating a grain-free diet. These circumstances may support additional claims. Veterinary records, echocardiogram results, cardiac bloodwork, or a necropsy report are particularly helpful.
- Note for Missouri Taste of the Wild purchasers: If you bought Taste of the Wild grain-free dog food in Missouri between August 27, 2015, and June 21, 2024, and were a Missouri citizen as of August 27, 2020, you may be a member of the certified class in Harmon v. Schell & Kampeter. See missouridogfoodclassaction.com for more information.
What You Can Do Now
- Talk to your veterinarian before making any change to your dog's diet or medication.
- Save the packaging — or photograph the front label and the full ingredient panel.
- Gather proof of purchase — receipts, Costco membership purchase history, credit card statements, or online order confirmations.
- Request your dog's veterinary records, including any echocardiogram, cardiac bloodwork, or cardiology consultation notes.
- Contact us using the form below. There is no cost and no obligation.
Frequently Asked Questions
Does my dog have to be sick for me to participate?
No. The lawsuits filed to date bring consumer-protection claims on behalf of people who purchased grain-free dog food, based on the allegation that they paid a premium for a product whose risks were not disclosed.
My dog seems perfectly healthy. Should I still be concerned?
DCM has a preclinical phase during which dogs often show no symptoms while cardiac changes are occurring. If your dog has been on a grain-free diet, you should discuss this with your veterinarian.
Do I need receipts?
Receipts help, but they are not required to contact us. Costco membership purchase history, credit card statements, online order records, and photographs of packaging are all useful.
How much does it cost to talk to a lawyer?
Nothing. Case evaluations are free, and we handle cases like this on a contingency-fee basis — meaning you owe no attorney's fees unless there is a recovery.
Is there a deadline?
Legal claims are subject to statutes of limitations that vary by state and by type of claim. If you believe you may be affected, do not wait to reach out.
Grain-Free Dog Food Investigation
