It’s been a “ruff” time lately for the pet food industry. Celebrity chef Rachael Ray was slapped with a $5 million lawsuit against her dog food brand, Nutrish, claiming that it contains harmful chemicals. According to reports, the food allegedly contains glyphosate, a herbicide found in common weed killers like Roundup.

In a separate blockbuster announcement, the Food and Drug Administration (FDA) issued an alert warning pet owners that popular grain-free foods containing peas, lentils, legumes or potatoes as the main ingredients cay cause a potentially fatal heart condition in dogs called canine dilated cardiomyopathy or DCM.

Canine DCM is a disease of a dog’s heart muscle and results in an enlarged heart, according to the FDA warning. As the heart and its chambers become dilated, it becomes harder for the heart to pump, and heart valves may leak, leading to a buildup of fluids in the chest and abdomen. DCM often results in heart failure.

Diets in cases of DCM that were reported to the FDA frequently list potatoes or multiple legumes such as peas, chickpeas and lentils as the main ingredients. High levels in these foods are more common in diets labeled “grain-free” because these carbohydrates are used to replace grains like rice, corn or wheat.

“We don’t want to be an alarmist, but this is a real signal.,” says Dr. Martine Hartogensis, a veterinarian who is deputy director for the Office of Surveillance and Compliance in the FDA’s Center for Veterinary Medicine.

There are no recalls yet, she said, and millions of dogs a happily and safely eating these diets. So far, the number of DCM cases reported to the FDA has been small but the numbers are increasing. Since the initial investigation, the administration has received reports of some two dozen additional cases. Three dogs died, according to The New York Times.

Some experts point to the low levels of taurine in some of the affected dogs’ blood. Taurine is an amino acid required for the development and function of the heart muscle cells, according to Texas A&M University. Some speculate that the legumes in grain-free food may interfere with the dog’s ability to make taurine or perhaps absorb it.

Grain-free diets account for a whopping 44 percent of sales in American specialty stores, or nearly $2.8 billion in sales.

Dana Brooks, chief executive of the Pet Food Institute, which represents most pet food manufacturers, said in an email statement to the Times:

“While the exact cause of the reported illnesses has not yet been identified, P.F.I. shares the belief that any pet illness should be taken seriously, and remind pet owners to consult their trusted veterinarians with any questions about their pet’s health and well-being.”

Dr. Lesley Hack, a Boca Raton, Florida, veterinarian tells Newsmax:

“I would avoid feeding a diet that has a high percentage of potatoes, peas, lentils, and chickpeas. You may also want to consider appropriate supplementation to support heart function, depending on your dog’s risk factors for heart disease. Always consult with your veterinarian before making any changes to your dog’s diet.”