FDA Grain Free Diets Update June 27, 2019
In July 2018, the FDA announced that it had begun investigating reports of canine dilated cardiomyopathy (DCM) in dogs eating certain pet foods, many labeled as "grain-free," which contained a high proportion of peas, lentils, other legume seeds (pulses), and/or potatoes in various forms (whole, flour, protein, etc.) as main ingredients (listed within the first 10 ingredients in the ingredient list, before vitamins and minerals). Many of these case reports included breeds of dogs not previously known to have a genetic predisposition to the disease. The FDA’s Center for Veterinary Medicine (CVM) and the Veterinary Laboratory Investigation and Response Network (Vet-LIRN), a collaboration of government and veterinary diagnostic laboratories, continue to investigate this potential association. Based on the data collected and analyzed thus far, the agency believes that the potential association between diet and DCM in dogs is a complex scientific issue that may involve multiple factors.
Cases Reported to FDA
For the purposes of this investigation, the FDA defines a “case” as an illness reported to FDA involving a dog or cat that includes a diagnosis of DCM by a veterinarian and/or veterinary cardiologist. Although the FDA first received a few sporadic reports of DCM as early as 2014, the vast majority of the reports were submitted after the agency notified the public about the potential DCM/diet issue in July 2018. Some of these reports involved more than one affected animal from the same household. Most dogs in the U.S. have been eating pet food without apparently developing DCM. It’s not known how commonly dogs develop DCM, but the increase in reports to FDA signal a potential increase in cases of DCM in dogs not genetically predisposed.
Dilated cardiomyopathy is recognized as a genetic condition in dogs, typically in large or giant breeds, such as the Doberman Pinscher, Great Dane, or the Irish Wolfhound. It is also seen in Cocker Spaniels associated with taurine deficiency. It is believed to be less common in small and medium breed dogs. We suspect that cases are underreported because animals are typically treated symptomatically, and diagnostic testing and treatment can be complex and costly to owners. FDA has observed a reporting bias for breeds like Golden Retrievers due to breed-specific social media groups and activities that have raised awareness of the issue in these communities and urged owners and vets to submit reports to FDA.
Additional breeds with more than one report include Afghan Hound, Australian Cattle Dog, Beagle, Belgian Tervueren, Border Collie, Boston Terrier, Bull Terrier, Chihuahua, Dalmatian, English Cocker Spaniel, English Springer Spaniel, Flat-coated Retriever, French Bulldog, Gordon Setter, Hound (unspecified), Irish Setter, Irish Soft-Coated Wheaten Terrier, Jack Russel Terrier, Maltese, Miniature Schnauzer, Old English Sheepdog, Pomeranian, Portuguese Water Dog, Pug, Retriever (unspecified), Rhodesian Ridgeback, Rottweiler, Rough-haired Collie, Saluki, Samoyed, Schnauzer (unspecified), Shepherd (unspecified), Staffordshire Bull Terrier, Standard Long-haired Dachschund, Vizsla, Whippet, and Yorkshire Terrier.
Genetic forms of DCM tend to affect male large and giant breed dogs beginning in middle to older age. DCM cases reported to FDA CVM have involved a wide range of dog breeds, ages and weights. There have been a greater proportion of males than females, consistent with what is seen in genetic forms. The significance of this is unknown, but it may be that some cases are genetic in origin or a combination of diet and genetic tendencies.
Diet Information from Reported Cases
When examining the most commonly reported pet food brands named in DCM reports submitted to the FDA, it is important to note that the graph is based on reports that included brand information and that some reports named multiple brands. Brands that were named ten or more times are featured below. FDA urges pet owners to work with their veterinarians, who may consult a board-certified veterinary nutritionist, to obtain the most appropriate dietary advice for their pet's specific needs prior to making diet changes.
Before the July 2018 DCM Update, FDA/Vet-LIRN had tested multiple products for minerals and metals (calcium, magnesium, phosphorus, iron, cobalt, copper, zinc, selenium, iodine) and amino acids including taurine, cysteine, and methionine. That product testing did not reveal any abnormalities.
Since the July 2018 DCM Update, Vet-LIRN tested both products labeled as "grain-free" and those containing grain for the following:
- protein, fat, moisture
- crude fiber, total dietary fiber, soluble fiber, insoluble fiber
- total starch, resistant starch
- cystine, methionine, and taurine
Additional food testing is in progress.
Taurine & Amino Acids
Nutritional research indicates that taurine is generally not considered an essential amino acid for dogs, because these animals can synthesize taurine from cysteine and methionine. Nearly all the grain-free products had methionine-cystine values above the minimum nutritional requirement of 0.65 percent for adult maintenance food for dogs published in the AAFCO Official Publication (OP).
The FDA is still gathering information to better understand if (and how) taurine metabolism (both absorption and excretion) may have a role in these reports of canine dilated cardiomyopathy.
Past publications and research suggest that Golden Retrievers may be genetically predisposed to taurine deficiency, which is well-documented as potentially leading to DCM.
Veterinary cardiologist Dr. Joshua Stern from the University of California at Davis has been studying the rise in cases of DCM in Golden Retrievers, including a potential dietary link. Many cases of DCM in Golden Retrievers are taurine deficient. Pet owners who suspect their Golden Retrievers may be affected may wish to consult their veterinarian to discuss checking taurine levels or conducting an echocardiogram.B
What you can do
If a dog is showing possible signs of DCM or other heart conditions, including decreased energy, cough, difficulty breathing and episodes of collapse, you should contact your veterinarian as soon as possible. If the symptoms are severe and your veterinarian is not available, you may need to seek emergency veterinary care. Your veterinarian may ask you for a thorough dietary history, including all the foods (including treats) the dog has eaten.
The FDA is continuing to investigate and gather more information in an effort to identify whether there is a specific dietary link to development of DCM and will provide updates to the public as information develops.
For complete report please click here.
FDA RELEASE 2018
What is the latest information about myocardial failure and grain-free diets?
As of July 2018, several cardiologists have examined this issue and have not come to a single conclusion — some have implicated diets and taurine deficiency in specific breeds (e.g. Golden Retrievers) (Olsen 2018) (Morris Animal Foundation 2017), while others have shown a relationship between the implicated diets and DCM but failed to find a strong association with taurine deficiency (Adin et al 2018).
In July 2018, the FDA issued a warning that some diets might be associated with DCM. However, the association is far from established or clear.
Which diets have been implicated?
Multiple diets have been implicated. One of the most common implicated diets is the Acana Pork and Squash Singles diet, although Nutrisource grain-free food has been mentioned as well. It is important to understand that any of the grain-free diets could be problematic (although there is currently no conclusive evidence that they are causal).
What should I do if I am feeding grain-free diets to my dog(s)?
There are several options;
- For dogs without cardiac clinical signs that appear healthy, changing the diet is the simplest and most conservative action until more definitive information relating to this emerging pattern is discerned.
- If you do not wish to change the diet as a preventive measure without more information, consider an echocardiogram and testing taurine concentration in plasma and whole blood.
- If myocardial failure is identified, change the diet and consider taurine supplementation regardless.
- If taurine concentration is low, change the diet and initiate taurine supplementation
- Repeat the echocardiogram in 4 to 6 months to assess resolution of the myocardial failure.
- Report your findings to the FDA.
- If you do not wish to change the diet or perform an echocardiogram, test the dog’s taurine concentration (plasma and/or whole blood).
- If low, supplement with taurine and strongly encourage changing diets to one not implicated in the problem.
- If normal, encourage the owners to keep abreast of evolving information on this issue.
- If you are unwilling to change the diet and are unwilling or unable to afford an echocardiogram and taurine analysis, strongly encourage the owners to supplement the diet with taurine, which is safe and inexpensive.