DCM FDA Data Update 2023
With the help of documents from Freedom of Information Act Requests, updated DCM case report information from the FDA is now available.
What is this about? Overview of FDA Investigation into Non-Hereditary Dilated Cardiomyopathy
Investigation has been ongoing for several years into atypical cases of a heart disease called dilated cardiomyopathy (DCM) in dogs. This disease is typically a hereditary genetic disease of certain breeds, such as Dobermans and Great Danes. With this disease, the heart muscle becomes thin and pumps less effectively. Cardiologists have reportedly been diagnosing a wider array of breeds with this disease in recent years. What sets these cases apart, other than breed, is that many are eating similar diets, and a large percentage of them improve and return to normal with a diet change and medical management, while DCM is typically a progressive and incurable condition even in the face of medical management.
Public awareness of this issue began in 2018, when the FDA announced that they were collecting reports of DCM suspected to be related to diet. In 2019, an update from the FDA provided additional data, including the most frequently reported brands of food. In their analysis, the FDA had found that a common factor among many cases was the dogs eating diets that were labeled as grain-free or that contained high amounts of peas and lentils. There was substantial pushback within the industry to this update, and since 2019, the FDA has not provided any updates of similar scope. In late 2022, they updated their website to reflect they would not be issuing any further public updates until there is “meaningful new scientific information to share.”
Researchers have not stopped seeking an answer to why these cases are occurring. Fifteen peer reviewed studies support a link between diet and atypical forms of DCM. Veterinarians, out of an abundance of caution and the emerging research, have continued to discourage patients from eating diets that contain suspect ingredients (peas, lentils, chickpeas) or are labeled as grain-free.
You can read more about DCM on the website’s dedicated DCM page.
Where is this data coming from?
In February 2023, Susan Thixton, consumer advocate and author at Truth About Pet Food, published FOIA documents obtained from an FDA Freedom of Information Act Request that listed all adverse food event reports submitted to the FDA up to 6/10/2022. Amidst these reports were reports of DCM as well as other adverse events such as vomiting and diarrhea, fanconi-like syndrome from jerky, etc. I began the painstaking task of converting the PDF files to Excel sheets, correcting errors that were generated from page breaks, and parsing out the DCM case data from the other adverse events. This endeavor was hours upon hours over weeks in the making.
April 25, 2023, a new FOIA document was published online, obtained by The Canine Review (and the help of David Schulz and the Media Freedom & Information Access Clinic at Yale Law School). This document contains only reports of DCM, and spans to November 2022. And so the endeavor began anew. The data presented below comes from the FOIA documents of only DCM case reports. However, I did cross reference the data I had already obtained from the all-adverse-events sheets, and congruency is present.
The data is likely imperfect. Adobe makes errors when converting PDFs to Excel charts, and some values had to be counted manually due to differences in spelling in the reports, etc. However, the purpose of the data, as discussed below, is to identify trends. It is unlikely that any small errors made in the data analysis are substantial enough to alter the overall trends.
Limitations
The FDA includes the following in their document:
“Limitations: The adverse event and product problem reports contained in this record are not necessarily causally related to (caused by) the reported product, nor do they mean the product was defective. Consumer complaints involving animal foods are received by FDA through voluntary reporting systems. Not all reports undergo follow up actions by FDA; however, each report received is important to FDA as part of our ongoing surveillance efforts related to pet food safety. Trends in reporting can provide an early warning of emerging safety issues of concern.
Other limitations:
• For any given report, there is no certainty that the reported pet food caused the adverse event. The adverse event(s) reported may be more related to an underlying disease, condition, or concomitantly administered medication.
• The report narratives are provided in the form in which we received them, the quality of the information provided about the adverse event/product problem is dependent on the quality of the information received from the veterinarian and/or pet owner.
• Adverse event report numbers should not be used to calculate incidence rates or measures of relative risk. It is not data from a controlled study, and there is no accurate way to know the true size of the population exposed to a product, nor the true population affected with an adverse event.
• Adverse event data should not be used to compare the safety of different products. Many factors can influence reporting, and products that are more widely distributed or sold in greater volume may have more reporting than those with limited distribution or sales. Products for which there has been recent publicity may experience more reporting for a period of time afterwards. Underreporting is also common with adverse event reporting systems.”
These are all valid limitations. Where adverse events reporting is useful is to pick up potential signals in the form of trends, and follow-up on those signals with research and investigation as appropriate.
In terms of DCM cases, some of the adverse event reports are from veterinarians and include echocardiographic data from ultrasound of the heart, and patient medical history. Other adverse event reports are from owners, some of whom have made a presumptive ‘diagnosis’ based on their pet’s symptoms and information they read online.
Again, in the FDA’s words, “For any given report, there is no certainty that the reported pet food caused the adverse event.” and “Trends in reporting can provide an early warning of emerging safety issues of concern.”
What is this information good for?
There are several important takeaways from this information:
Perhaps most important, these cases are still occurring and still being reported, albeit at a lesser frequency. Given that case reporting tends to spike with announcements regarding an investigation, it makes sense that reporting has decreased alongside the FDA's relative silence on the matter.
The trends in breed, weight, age, sex, and food brand have remained relatively static. Comparing the data side-by-side, it is readily apparent that other than an increase in numbers, not much has changed about the populations this disease is being reported within.
Certain manufacturers continue to be overrepresented relative to their market share, and a wide variety of breeds continue to be represented.
Below, you'll find the charts from the FDA's 2019 update as well as the new charts that I have generated from the FOIA documents linked at the start.
FDA chart, source: https://www.fda.gov/animal-veterinary/outbreaks-and-advisories/fda-investigation-potential-link-between-certain-diets-and-canine-dilated-cardiomyopathy
January 2014 - April 2019
Data generated by author based on FOIA documents. May 2019 - November 2022.
Combined chart using previous two data sets.
FDA chart, source: https://www.fda.gov/animal-veterinary/outbreaks-and-advisories/fda-investigation-potential-link-between-certain-diets-and-canine-dilated-cardiomyopathy
January 2014 - April 2019
Data generated by author based on FOIA documents. May 2019 - November 2022.
FDA chart, source: https://www.fda.gov/animal-veterinary/outbreaks-and-advisories/fda-investigation-potential-link-between-certain-diets-and-canine-dilated-cardiomyopathy
January 2014 - April 2019
Data generated by author based on FOIA documents. May 2019 - November 2022.
FDA chart, source: https://www.fda.gov/animal-veterinary/outbreaks-and-advisories/fda-investigation-potential-link-between-certain-diets-and-canine-dilated-cardiomyopathy
January 2014 - April 2019
10 or more cases
Data generated by author based on FOIA documents. May 2019 - November 2022. Greater than 10 cases.
Combined chart using data from previous two sets. 20 or more cases.
This data establishes an ongoing signal of concern. Again, it does not, alone, demonstrate causality. However, it justifies continued research into this area to determine why these trends are being observed. You can find a list of the research on this issue here.
What Can I Do If I Suspect My Dog May Be Affected?
Talk to your vet!
From the FDA, "Detailed instructions for submitting case information can be found on “How to Report a Pet Food Complaint.""