Petco lawsuit claims WholeHearted grain-free dog food linked to fatal heart disease in dogs

A New York woman has filed a class action lawsuit against Petco Health and Wellness Company, alleging the company's WholeHearted grain-free dog food is falsely marketed as a healthy and nutritionally complete pet food, despite being linked to a deadly heart disease in dogs.

The plaintiff, Mina Maiman of Port Washington, N.Y., says her dog developed a fatal heart condition after eating the product and died.

Maiman says she made a deliberate decision to switch her dog Oskar to Petco's WholeHearted grain-free line because she believed the company's marketing claims.

According to the complaint, the WholeHearted grain-free products were labeled with phrases such as "Complete Nutrition," "Vitamins & Minerals for Balanced Nutrition," and "Thoughtfully crafted [with] maximum benefits." The lawsuit contends those claims are false and misleading, and that they led consumers like Maiman to pay a premium price for a product the complaint says could seriously harm their pets.

The outcome described in the lawsuit was devastating. After Oskar consumed the WholeHearted grain-free products, the dog developed dilated cardiomyopathy, a condition commonly known as DCM. DCM is a serious disease in which the heart muscle enlarges and weakens over time. As the condition progresses, it can lead to congestive heart failure, which makes it increasingly difficult for the heart to pump blood through the body.

Alleged health-washing

The complaint focuses on a practice it calls health-washing. That term refers to when a company uses health-focused language in its marketing to create a false impression that a product is safer or more beneficial than it actually is.

According to the lawsuit, grain-free dog food does not deliver the complete nutrition that Petco's labels promise. Instead, the complaint alleges, this type of diet carries a substantial risk of nutritional imbalance for dogs.

Rather than using traditional grains, WholeHearted grain-free products allegedly rely on ingredients such as peas, lentils, chickpeas, and pea flour. The lawsuit alleges that multiple peer-reviewed studies have linked high-legume ingredient profiles like these to serious and sometimes fatal health problems in dogs. Those alleged health issues include DCM, taurine deficiency, decreased red blood cell counts, and other harmful health markers.

The U.S. Food and Drug Administration has also been examining this issue closely. According to the complaint, the FDA has been investigating a possible connection between grain-free pet foods and canine DCM since 2019. The lawsuit notes that a surge in reported canine DCM cases has coincided with the growing popularity of grain-free pet diets during that same period.

This case follows other class action lawsuits tied to grain-free dog food and DCM, reflecting a broader wave of legal scrutiny around grain-free pet food marketing in the United States.

How are WholeHearted consumers affected?

Maiman and the proposed class are seeking several forms of relief that covers purchases of WholeHearted grain-free dog food made from at least Jan. 1, 2022, through today.

On the financial side, the complaint asks for actual damages to compensate consumers for money lost by paying a price premium for the products. The lawsuit also seeks statutory damages as defined by New York law and restitution, which would require Petco to return money consumers paid for the grain-free products.

Additionally, the complaint requests treble damages, which would allow the court to award up to three times the amount of actual damages if certain legal conditions are met.

Beyond financial relief, the plaintiff wants the court to order Petco to take specific actions. The complaint asks the court to require Petco to update its labeling on WholeHearted grain-free products to include proper health warnings and to stop making marketing claims that the lawsuit says are not backed by science.

Petco has not yet publicly responded to the allegations in the complaint. The case is in its early stages, and no trial date has been set. The complaint states that the class is expected to include a large number of consumers, given the nationwide scope of Petco's retail footprint.

Maiman v. Petco Health and Wellness Company, Inc., was filed on March 16, 2026, in the U.S. District Court for the Eastern District of New York.