feeding your golden retriever

Updated 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.

We understand the concern that pet owners have about these reports:  the illnesses can be severe, even fatal, and many cases report eating  “grain-free” labeled pet food. The FDA is using a range of science-based  investigative tools as it strives to learn more about this emergence of  DCM and its potential link to certain diets or ingredients.

Following an update in February 2019 that covered investigative  activities through November 30, 2018, this is the FDA’s third public  report on the status of this investigation.

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. Many of the reports submitted to the FDA included  extensive clinical information, including echocardiogram results,  cardiology/veterinary records, and detailed diet histories. The numbers  below only include reports in which the dog or cat was diagnosed with  DCM by a veterinarian and/or veterinary cardiologist. We did not  include in these numbers the many general cardiac reports submitted to  the FDA that did not have a DCM diagnosis. However, this case  information is still valuable, as it may show heart changes that occur  before a dog develops symptomatic DCM. 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.

Between January 1, 2014 and April 30, 2019, the FDA received 524  reports of DCM (515 canine reports, 9 feline reports). Approximately  222 of these were reported between December 1, 2018 and April 30, 2019  (219 canine reports, 3 feline reports). Some of these reports involved  more than one affected animal from the same household. The breakdown of  reported illnesses below reflects the number of individual animals  affected. The American Veterinary Medical Association estimates that  there are 77 million pet dogs in the United States. 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 under reported  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. 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.

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.

Review of the canine reports shows that most reports were for dry dog  food formulations, but raw food, semi-moist food, and wet foods were  also represented. 

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  below 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. 

To better characterize diets reported in DCM cases, product labels  were examined to determine whether the product was grain-free (did not  contain corn, soy, wheat, rice, barley or other grains), and whether the  products contained peas, other lentils including chickpeas and beans,  or potatoes (including sweet potatoes).  Because so many products  contained peas and/or lentils, a category was created for “peas and/or  lentils”. More than 90 percent of products were “grain-free”, and 93  percent of reported products had peas and/or lentils.  A far smaller  proportion contained potatoes.

Animal protein sources in the reported diets varied widely, and many  diets contained more than one protein source.  The most common proteins  in the reported diets were chicken lamb and fish; however, some diets  contain atypical protein sources such as kangaroo, bison or duck. No one  animal protein source was predominant.

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

The average percent protein, fat, total taurine, total cystine,  total methionine, total methionine-cystine, and resistant starch content  on a dry matter basis (in other words, after removing all moisture  content) were similar for both grain-free labeled and grain-containing  products. 

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.

Vet-LIRN has interviewed 95 owners of affected dogs and cats to  document the pets’ complete dietary history and to explore any other  factors that could have potentially contributed to development of DCM,  such as environmental factors like heavy metal exposure or poisonous  plant ingestion.

In addition, Vet-LIRN has contracted with a network lab to collect  blood (whole blood and plasma), urine, feces, and DNA from dogs without a  known breed predisposition to DCM (as a point of comparison) to send to  Vet-LIRN for testing.

As of April 30, 2019, Vet-LIRN has reviewed results of 19 gross  necropsies from dogs with suspected heart disease, including  13 necropsies that Vet-LIRN coordinated from cases reported through the  FDA Safety Reporting Portal. There is one additional necropsy pending  evaluation. The gross necropsies were performed by either veterinarians  or veterinary pathologists, and Vet-LIRN is currently processing tissues  for histopathology. A board-certified veterinary pathologist will  review the histopathology slides.

Vet-LIRN has been collaborating with Chesapeake Veterinary Cardiology  Associates (CVCA) to collect medical records, an owner interview, and  diagnostic samples from pets with DCM that were diagnosed by a  board-certified veterinary cardiologist by echocardiogram. These cases  are included in the overall number of DCM cases, but were selected for  further study because their ongoing program of care with the practice  will be comprehensively documented and provided in full to Vet-LIRN.

Upon confirmation of a DCM diagnosis, CVCA collects blood (whole  blood and plasma), urine, feces, DNA swabs, and food, if the pet is not  receiving any supplements (e.g. taurine, cystine, or methionine) and is  still eating a diet labeled “grain-free.” Vet-LIRN will test the blood  and urine for taurine, cystine, methionine, and other amino acids.  Vet-LIRN is archiving feces and DNA from these cases for possible future  testing.

CVCA will repeat collection of urine, blood, and feces at 1 to 2  months, and at 6 months after the initial diagnosis and document any  treatment or dietary changes, if any, that were recommended by the  cardiologist. The repeat urine and blood samples will be tested for  amino acid content and the feces archived. At the 6-month recheck, CVCA  will also conduct a repeat echocardiogram to assess any changes to the  heart. As of April 30, 2019, CVCA and Vet-LIRN have collected initial  samples from 14 dogs, and 1 to 2-month samples from 10 dogs. CVCA is  currently collecting the 6-month samples.

Of the original 14 dogs in this cohort, five dogs have been lost to  follow-up at various points after the initial sample collection,  including 4 deaths, and will not complete the sample collection.  Vet-LIRN is currently evaluating the heart histopathology for two of the  deceased dogs. The initial and 1 to 2-month blood and urine samples for  14 and 10 dogs, respectively, have been tested and are being evaluated.

Vet-LIRN is also collecting food associated with each CVCA case and will test each diet for:

• protein, fat, moisture
• crude fiber, total dietary fiber, soluble fiber, insoluble fiber
• total starch, resistant starch
• free and total cystine, methionine, and taurine

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.

When unprecedented events such as these occur, the FDA often consults  with stakeholders across the animal health community to help fill any  knowledge gaps that may help inform its investigation. These  collaborations can help provide pieces to complete the puzzle and allow  us to gain a better understanding of what happened.

FDA veterinarians have been working with the veterinary community to  exchange information about existing cases and the type of clinical  information that is most helpful to the investigation. We are also  consulting with a cadre of board-certified veterinary cardiologists and  nutritionists to learn more about the presentation of these cases and  how they respond to treatment.

Chesapeake Veterinary Cardiology Associates (CVCA), a multi-location  veterinary cardiology practice based predominantly in the Mid-Atlantic  states, has provided comprehensive records for some DCM cases (including  medical records, owner interviews, and diagnostic samples from pets  with DCM diagnosed with an echocardiogram by a board-certified  cardiologist) to the Vet-LIRN network for further testing. These case  records include imaging studies of the animal’s hearts, comprehensive  dietary histories, diagnostic and treatment records, as well as outcomes  of the cases.

FDA veterinarians have been working with Drs. Lisa Freeman of Tufts  University, Joshua Stern of UC Davis and Darcy Adin of the University of  Florida to learn more about their research findings and the cases  they’ve encountered. The three were contributing authors to a paper  published in Journal of American Veterinary Medical Association in  December 2018, “Diet-associated dilated cardiomyopathy in dogs: what do we know?External Link Disclaimer"

As animal lovers and pet owners, FDA employees understand that the  sudden onset of a life-threatening disease in a previously healthy pet  can be devastating. The FDA is incredibly grateful to those pet owners  who have agreed to be interviewed and given permission for their  veterinarians to share medical records and diagnostic samples, including  blood, serum and tissue. The agency is especially appreciative when pet  owners make the difficult decision to provide tissues for analysis when  a beloved pet passes away. The FDA believes that the information gained  will help the FDA to understand the specific changes that are happening  in the cardiovascular system and how they may relate to diet.

Another puzzling aspect of the recent spike in DCM cases is that they  have occurred just in the last few years. 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.

The FDA is open to additional opportunities for collaboration and  welcomes the submission of any information that may aid in our  investigation.

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.

CVM encourages veterinary professionals to report well-documented  cases of DCM in dogs suspected of having a link to diet by using the  electronic Safety Reporting Portal.  The more information you are able to provide, particularly about  feeding history, medical records, and diagnostic testing, the better.  

The FDA looks to industry organizations and pet food manufacturers to  contribute to the FDA's investigation while continuing their own  investigations to help shed light on potential issues with formulas or  ingredients.

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.