MYTH: “Only 560 U.S. Dogs Have Nutritional DCM”

MYTH: “Only 560 U.S. Dogs Have Nutritional DCM”

by Allison Fogel, PhD, Group Administrator – Diet-Associated Dilated Cardiomyopathy (DCM) in Dogs

Responses from manufacturers of dog foods named in the FDA’s June 2019 update, as well as stores that sell these foods, continue to peddle inaccurate information to minimize the number of dogs impacted by diet-associated dilated cardiomyopathy (DCM).

Here’s what they’re spreading around: “DCM impacts less than 1% of U.S. dogs, with .000007% supposedly related to diet” based on the 560 cases included in the FDA update.

Here’s why those numbers are wrong:

  1. 560 cases reported to the FDA out of 77 million U.S. dogs is .0007% — not .000007%. The .000007% figure seems to have originated with a manufacturer and was then widely repeated. Let this be a cautionary tale in considering sources of information. Manufacturers have a responsibility to distribute accurate data, especially those who expect to be trusted to properly calculate percentages for balanced foods.
  2. To come up with an accurate percentage of U.S. dogs affected by nutritional DCM, it must first be known how many dogs eating BEG diets have had echocardiograms – not how many dogs are in the entire country. One way to find this out would be for manufacturers to pay for echoes for a number of dogs eating their diets and learn how many are affected.
  3. The number of IMPACTED dogs is higher than the number of dogs REPORTED to the FDA. The FDA stated: “We suspect that cases are underreported because animals are typically treated symptomatically, and diagnostic testing and treatment can be complex and costly to owners… 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.”

“We don’t know the true scope of the problem.”

That’s what board-certified veterinary nutritionist Dr. Lisa Weeth reported in her article following the FDA update. From the article: “In people, underreporting of adverse drug effects is a well-known problem with some reviews indicating that as high as 95% of adverse reactions go unreported.”

This means we may only be seeing 5% of the actual cases of dogs affected by diet-associated DCM. 

The diagram below illustrates the steps that must happen for a case of diet-associated DCM to be reported to the FDA – and why many cases are not reported or captured by reporting systems.

  1. It has to be detected in the first place. Dogs with DCM often show no symptoms until the disease is quite advanced, so many dogs may be asymptomatic in earlier stages of the disease. Other dogs may have suddenly passed away with no indication of the cause, no echocardiogram and most often, no necropsy.
  2. It has to be formally diagnosed. DCM can only be diagnosed with an echocardiogram, which for many owners is not accessible or affordable. As the FDA notes, many animals are treated for symptoms of heart disease without knowing or determining the precise cause.
  3. It has to be reported to the FDA. Families with dogs affected by DCM are overwhelmed by a serious new diagnosis, and there may be confusion as to who is responsible for reporting to the FDA – which can be the pet owner, the cardiologist or referring veterinarian. Owners might not file a report if they don’t have their dog’s full medical records. It’s important to note that the FDA can contact vets, so it’s okay for owners to file without them.


  1. Know your sources of information.
  2. The percentage of affected U.S. dogs bandied about by deniers of this disease is grossly inaccurate.
  3. The number of documented cases is likely only a fraction of the number of dogs affected by diet-associated DCM.
  4. Knowing the actual percentage of affected dogs would require that all dogs eating BEG diets have echocardiograms performed to determine how many are affected.

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