'We Just Aren't Sure Which Way To Go': FDA IDs Dog Foods Possibly Linked With Fatal Heart Disease

MINNEAPOLIS (WCCO) -- The Food and Drug Administration has now investigated more than 500 cases of canine heart disease linked with grain-free dog food.

WCCO's Christine Cordero first reported on the issue last October, and earlier this year the FDA confirmed grain-free dog food may have contributed to the deaths of hundreds of dogs.

Five-year-old Goldendoodle Marshall is not just a furry friend to Nick Nascene -- he's family.

"He really is the love of our life," Nascene said.

When the FDA first alerted pet owners about a possible link between grain-free food and sick dogs, he wasn't sure what to do.

"Before we started hearing about that, we fed Marshall exclusively grain-free because he's always had a bit of a sensitive stomach," Nascene said. "Since that came out, we are a little bit confused. We are actually mixing a little bit and giving him some of both. We just aren't sure which way to go."

On Thursday, the FDA updated on their investigation of about 500 cases, saying that Golden Retrievers are the most common dog breed afflicted with dilated cardiomyopathy, however there may be a reporting bias because of Facebook groups specific to Golden Retrievers with the condition.

The FDA also identified one of the most-named brands connected with dilated cardiomyopathy: Minnesota's NutriSource, with at least 10 cases. That was one of the brands that Cordero covered in her initial WCCO report. We reached out to NutriSource for comment on the new report, and have not received a response as of Thursday evening.

Other brands had as many as 50 or 60 reports of the illness. University of Minnesota Veterinary nutritionist Dr. Julie Churchill believes there is no benefit to feeding your dog any brand of grain-free food.

"My take away is don't look at that list and just say, 'My dog is not eating that brand.' Remember that those are only the brands that have been reported," Churchill said.

While this is a significant update, the investigation isn't complete. Until the FDA reaches a definitive conclusion, consult your vet on the best diet for your dog.

More than 90% of dog food products identified were "grain-free," and 93% reported products had peas and/or lentils.

Click here for a list of the dog foods the FDA is identifying.