Potato-based pet foods may be causing heart disease in dogs, the U.S. Food & Drug Administration warned this week.

The government agency is investigating a potential link between pet foods with peas, lentils, potatoes and other legume seeds and instances of canine dilated cardiomyopathy in dogs not typically vulnerable to the disease. “Highly unusual” reports of these dogs contracting the disease prompted the FDA to investigate their food sources, which, the agency notes, largely contained those certain ingredients.

Found typically in larger breeds of dogs like Great Danes and Newfoundlands, canine dilated cacdiomypatohy enlarges the heart, thus weakening it and often leading to heart failure. The FDA said dogs that are not genetically predisposed to the disease, like Labrador Retrievers, Shih Tzus, and Bulldogs, all of whom had a diet largely based in pet foods that contained lentils, peas and potatoes, have reportedly had the disease.

The FDA said it is contacting pet food manufacturing companies and veterinarians about this potential link. Representatives from Mars Petcare and Nestlé Purina, two of the biggest pet food manufacturers, did not respond immediately to requests for comment.

“We encourage pet owners and veterinarians to report DCM cases in dogs who are not predisposed to the disease,” Martine Hartogensis, deupty director of the FDA’s Center for Veterinary Medicine’s office of Surveillance and Compliance, said in a statement.

Get our Health Newsletter. Sign up to receive the latest health and science news, plus answers to wellness questions and expert tips. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Contact us at letters@time.com.