Out of 560 individual dogs affected by canine dilated cardiomyopathy (DCM), 119 dogs died in the cases reported to the U.S. Food and Drug Administration between January 1, 2014 and April 30, 2019. Fourteen cats were stricken with a related heart disease, and five of them died in FDA reports.

“Because the occurrence of different diseases in dogs and cats is not routinely tracked and there is no widespread surveillance system like the Centers for Disease Control and Prevention have for human health, we do not have a measure of the typical rate of occurrence of disease apart from what is reported to the FDA,” wrote FDA officials in an update issued June 27.

Top 5 dog breeds involved in federal DCM investigation

  1. Golden Retriever – 95 cases
  2. Mixed – 62 cases
  3. Labrador Retriever – 47 cases
  4. Great Dane – 25 cases
  5. Pit Bull – 23 cases

A wide range of dog breeds developed DCM. However, all but the top five appeared in fewer than 20 cases.

No causation found between dog food ingredients and DCM

While the FDA has found these correlations, they have found no causality. Thousands of dogs have eaten the same diets as the dogs stricken with DCM, to no ill effect. FDA lab analysis of grain-free versus conventional dog foods revealed little difference in levels of minerals, amino acids, taurine, protein or other nutrients.

“Another puzzling aspect of the recent spike in DCM cases is that they have occurred just in the last few years,” wrote FDA officials in the update. “The FDA is working with the pet food industry to better understand whether changes in ingredients, ingredient sourcing, processing or formulation may have contributed to the development of DCM."

Stopping grain-free diet, adding taurine helped dogs’ DCM

Speaking of Golden Retrievers and DCM, scientists documented that specific diets were associated with the development of taurine deficiency in that breed, which may increase the risk of dilated cardiomyopathy.

The scientists published the results of their research, “Taurine deficiency and dilated cardiomyopathy in golden retrievers fed commercial diets,” in the journal PLOS ONE.

In the study, 23 out of 24 Golden Retrievers diagnosed with taurine deficiency and dilated cardiomyopathy ate grain-free and/or legume-rich dog food diets. The majority of those dogs’ health improved after diet change and taurine supplementation.

“Taurine deficiency and dilated cardiomyopathy in golden retrievers is likely multifactorial, including a combination of dietary, metabolic and genetic factors,” the researchers, led by a team from the School of Veterinary Medicine University of California - Davis, wrote in their conclusions.

Details of research on dogs with dilated cardiomyopathy

The researchers’ study involved 24 client-owned golden retrievers with documented taurine deficiency and dilated cardiomyopathy, along with 52 healthy client-owned golden retrievers.

All but one of the dogs diagnosed with taurine deficiency and dilated cardiomyopathy ate diets that were either grain-free, legume-rich or a combination of these pet food trends.

“None of these diets were feeding trial tested using Association of American Feed Control Officials (AAFCO) procedures,” wrote the researchers.

All but one of the dogs significantly improved their heart health, as measured by an echocardiogram, after diet change and taurine supplementation. Taurine concentrations in their blood also normalized.

“All dogs with DCM in this study were consuming diets with similar characteristics, including grain-free, uncommon protein based, or legume-rich formulations...” wrote the researchers. “Although a cause and effect relationship cannot be proven, the associations are concerning and warrant caution as well as future prospective studies.”