How dog heart disease has been linked to grain-free dog food

(AP) — In 2018, the U.S. Food and Drug Administration, based on input from a group of veterinary researchers, began investigating whether the growing popularity of grain-free dog foods led to a sudden rise in fatal heart disease in dogs. Cardiac dilation.

Four years later, the FDA has found no strong link between diet and dilated cardiomyopathy. Nor did she reject such a link, and research is ongoing. However, the publicity surrounding the issue has dented the promising market for grain-free dog foods.

Moreover, a tangled web of funding and industry interests appears to have influenced the origin, data collection, and trajectory of the FDA study, according to internal FDA records.

A six-month investigation by 100Reporters found that veterinarians who urged the Food and Drug Administration to consider the diet had financial and other ties to major vendors of all-grain pet foods. Additionally, agency records show that for the initial study, some veterinarians were directed to present cases of dilated cardiomyopathy (DCM) that indicated the involvement of grain-free, “exotic”, or “boutique” pet foods. Suppliers of ingredients used in grain-free dog foods have also put pressure on the Food and Drug Administration to protect their markets.

Thus, the conversation about DCM and grain-free foods is deeply divided, with each side claiming that the other prioritizes industrial relations over scientific integrity and the lives of pets.

“This has become a very emotional issue,” said Dana Brooks, executive director of the Pet Food Institute, whose members produce most pet foods in the United States. “We’re struggling to try to determine what’s going on.”

cause for concern

Grain-free pet diets became popular in the early 2000s, relying heavily on pulses – the seeds of legume plants including peas, beans, and lentils. By 2019, grain-free foods accounted for 43 percent of dry pet foods sold.

As of 2017, the Food and Drug Administration saw one to three reports of DCM per year. But between January 1 and July 10, 2018, it received 25 cases. An FDA spokesperson said seven reports came from one source, animal nutritionist Lisa Freeman of the Cummings College of Veterinary Medicine at Tufts University. However, FDA records obtained under the Freedom of Information Act indicate that these reports may not be fully representative of the cases seen at Tufts Clinic.

In a June 2018 email to FDA Veterinary Medical Officer Jennifer Jones, Freeman enclosed a document instructing veterinarians to report cases to the FDA, “if a patient eats any diet other than those prepared by well-known and reputable companies or If he eats a weird shop or a grain-free (BEG) diet.”

When asked if this could be considered as cherry-picking data that would shape the investigation, Freeman stated through Tufts Media Relations: “The protocol in this email was developed in order to assist veterinary cardiologists in the early stages of investigating potential associations Between diet and dilated cardiomyopathy”.

“I shared the protocol with the Food and Drug Administration to inform them of our clinical recommendations for patients at the time,” Freeman wrote, noting that they “continue to study ‘any diet that contains DCM-related ingredients’ regardless of the manufacturer.”

In an email, an FDA spokesperson wrote, “The FDA has never required that cases of DCM reported to the agency be limited to certain types of diet. We welcome all reports of DCM suspected of being associated with food, regardless of diet type. food.”

According to, Freeman has received funding from major sellers of holistic grain foods, including Nestle Purina Petcare, Hill’s Pet Nutrition, and Mars Petcare, since 2002. Her recent statements about conflicts of interest state: “In the last 3 years, Dr. Freeman has received Research funding from, sponsored lectures and/or professional services to Aratana Therapeutics, Elanco, Hill’s Pet Nutrition, Nestlé Purina PetCare, P&G Pet Care (now March), and Royal Canin.”

Industry funding is common in animal nutrition science. Freeman said she is behind her research and has “transparently disclosed the sources of funding for the work I’m doing on this topic.”

Two veterinary cardiologists — Darcy Adin of the University of Florida College of Veterinary Medicine and Joshua Stern of the University of California, Davis College of Veterinary Medicine — also collaborated with the Food and Drug Administration.

Emails from the Public Records Request indicate that in April 2018, Jones spoke with Freeman, Stern and Adin about grain-free dog foods and DCM and requested spreadsheets for their clinical case data.

Adin has been involved in studies that have received funding from Purina since 2018, and since 2017, from the Morris Animal Foundation, the nonprofit animal health charity founded by Mark Morris Sr., who created the company’s first line of dog foods that would become Hill’s Pet Nutrition.

The University of Florida Public Relations said neither Adin nor the university received direct financial support from companies for these studies.

Stern has authored studies funded by the Morris Foundation for Animals since 2011, and is currently receiving funding from the foundation.

“I fully understand the conflict of interest concerns with people funded by the pet food industry,” Stern said. “It’s hard to find a veterinary dietitian who hasn’t done research for pet food companies.”

Purina, Hill’s, and Mars did not respond to multiple requests for comment.

In July 2018, the US Food and Drug Administration (FDA) announced its investigation, stating that many of the 25 dogs diagnosed lacked a genetic predisposition to DCM. The common denominator, she said, appears to be a grain-free diet.

A year later, the U.S. Food and Drug Administration (FDA) took the unusual step of naming 16 dog foods, nearly all of them grain-free, that appeared frequently in their DCM case reports. “We’ve never seen anything like this before without the certainty of why,” Brooks said.

Joseph Bartjes, professor of animal nutrition at the University of Georgia, was not surprised, noting that the Food and Drug Administration had put a label on grain-free food early on. “When you only look for what you want to see, you only see what you look for,” Bartjes said. By July 2020, the number of DCM reports was 1,100 — likely the result of the FDA encouraging people to report illness,” Brooks said.

Influential Industry

Grain-free ingredient suppliers, in turn, have mobilized forces to protect their market share.

In its 2019 annual report, the USA Pea and Lentil Council said it had “convinced the US Food and Drug Administration to clarify its language on their concerns and minimize harm to the industry.”

In a 2019 letter to Food and Drug Administration officials, Senator John Tester of Montana — a major legume growing region — complained that the agency’s “unfounded warning” had hurt legume farms. The following year, seven senators signed another letter to the Food and Drug Administration suggesting there might be a “bias about causing this disease.”

The Food and Drug Administration has consistently stated that DCM includes multiple agents. Shortly after the letter, Stephen Solomon, director of the Food and Drug Administration’s Center for Veterinary Medicine (CVM), emphasized the point, calling DCM “a scientifically complex and multifaceted issue,” adding, “We . . . at the moment are not looking at This is seen as a regulatory problem.”

An FDA spokesperson wrote that as he met with stakeholders, “Ultimately, all FDA decisions and actions are informed by science, data, and our public health mission.”

Regardless of the final results of the investigation, sales of grain-free dry dog ​​food have declined since June 2018 and decreased by $60 million from 2021 to 2022. Meanwhile, overall sales of grains increased in 2019 and rose by $700 million from 2020 to 2021.

Getting an answer on DCM will be challenging thanks to the complexity of the impact of science and industry, said Marion Nestle, author of Pet Food Policies. “They are all trying to protect their market share.”


This article is an abridged version of an investigation released by 100Reporters, a nonprofit investigative news organization, with financial support from the Investigative Journalism Fund and legal guidance from the Reporters Committee for Press Freedom.


This story was first published on July 20, 2022. It was updated on July 23, 2022 to correct that the Morris Animal Foundation founder created the company’s first line of dog food that would become Hill’s Pet Nutrition, but did not. start the company and remove the erroneous reference to the enterprise headed by the employee of Hills Pet Nutrition; Not.

Copyright 2022 The Associated Press. All rights reserved.

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