The US Food and Drug Administration (FDA) received a total of 524 reports of companion animals stricken with dilated cardiomyopathy (DCM) between January 1, 2014 and April 22, 2019, according to an update released by the agency today.

Some of the reports involve multiple animals in a single household. In all, DCM was reported in 560 dogs and 14 cats. Five cats and 119 dogs died.

Only seven reports were lodged with FDA during calendar years 2014-2017. The number of incidents spiked to 320 in 2018, and have continued at a steady pace this year, with 197 cases reported between January 1st and April 30th 2019.

FDA has posted a spreadsheet containing all of the individual reports it has received.

BY THE NUMBERS

The ten breeds appearing most often in these reports include: Golden Retriever (95), Mixed (62), Labrador Retriever (47), Great Dane (25), Pit Bull (23), German Shepherd (19), Doberman Pinscher (15), Australian Shepherd (13), Unknown (13) and Boxer (11).

DCM is recognized as a genetic condition in some large or giant breed dogs, including the Doberman Pinscher, the Great Dane, and the Irish Wolfhound, manifesting mainly in male dogs in middle to older age. DCM also is associated with taurine deficiency in Cocker Spaniels.

In contrast, cases of DCM reported to FDA have involved a wide range of dog breeds of all sizes and ages, from 0.4 – 17 years in dogs and 7 – 13 years in cats. More than one half of the cases (58.7% of dogs and 62.5% of cats) involve males.

The vast majority of affected pets (452 of the 524 reports) were fed a dry food diet exclusively. The rest of the animals were fed a diet that included one or more of dry, raw, semi-moist or wet foods. 

More than 90% of the dry dog foods were grain-free. Ninety-three percent of the formulations contained peas and/or lentils. Forty-two percent contained potatoes or sweet potatoes.

The most common animal source proteins were chicken, lamb and fish. Some foods contained exotic meats, such as kangaroo or bison. No one animal protein source predominated in the illness reports.

Dry food brands named most frequently in DCM cases were Acana (67), Zignature (64), Taste of the Wild (53), 4Health (32), Earthborn Holistic (32), Blue Buffalo (31), Nature’s Domain (29), Fromm (24), Merrick (16), California Natural (15), Natural Balance (15), Orijen (12), Nature’s Variety (11), NutriSource (10), Nutro (10) and Rachael Ray Nutrish (10).

THE FDA INVESTIGATION

FDA’s Veterinary Laboratory Investigation and Response Network (Vet-LIRN) has analyzed multiple products for minerals and metals (calcium, magnesium, phosphorus, iron, cobalt, copper, zinc, selenium, iodine) and amino acids including taurine, cysteine, and methionine. No abnormalities were found.

A comparative test of grain-free and grain-containing products for levels of protein, fat, moisture, crude fiber, total dietary fiber, soluble fiber, insoluble fiber, total starch, resistant starch, cystine, methionine and taurine revealed that both types of products contained similar levels of all of these components on a dry matter basis (ie., after removing all moisture content).

Additional tests are in progress

Vet-LIRN has interviewed 95 owners of affected pets, in order to document a complete dietary history and to explore any other possible contributing factors, including environmental factors.

FDA has received results of 19 gross necropsies from dogs with suspected heart disease, and Vet-LIRN is processing tissues from the necropsies for review by a board-certified veterinary pathologist.

Vet-LIRN is collaborating with Chesapeake Veterinary Cardiology Associates (CVCA) to collect medical records, owner interviews, and diagnostic samples from pets diagnosed with DCM. CVCA will be following the medical progress of these pets, including regular collection of diagnostic samples and follow-up echocardiogram. Vet-LIRN is collecting food associated with the pets included in this study for lab analysis.

UNANSWERED QUESTIONS

1. Why have cases of DCM spiked in recent years? What has changed?
2. Why are grain-free products so strongly associated with DCM, even though there is little apparent difference in the levels of minerals, amino acids, protein levels, etc. between grain-free and grain-containing products?
3. Acana (67 DCM reports) and Orijen (12 DCM reports) are both manufactured by the same company. Why is there such a large difference in the number of associated cases between these two brands?
4. Is there any correlation between brand popularity and number of DCM case reports? Would it be useful to compare the report frequency to the market share of each product?

WHAT CAN PET OWNERS AND VETERINARIANS DO?

• FDA encourages pet owners and veterinarians to submit reports on any food-associated pet illness. Details for submitting this info can be found on the FDA page “How to Report a Pet Food Complaint.”
• Pet owners should contact a veterinarian as soon as possible if their dog is showing possible signs of DCM or other heart conditions, including decreased energy, cough, difficulty breathing and episodes of collapse.
• Veterinarians are urged to report well-documented cases of DCM in dogs suspected of having a link to diet by using the electronic Safety Reporting Portal or calling their state’s FDA Consumer Complaint Coordinators. FDA especially welcomes detailed reports, including information about feeding history, medical records, and diagnostic testing.

AN EDITORIAL NOTE

I have sometimes read complaints from pet owners and at least one blogger that FDA doesn’t care about pet food safety, or about the health of companion animals. 

The agency has spent significant resources and manpower on this investigation for more than a year, and is continuing its efforts to find the root cause for the spike in DCM in dogs. This is a complex, difficult, and wide-reaching investigation with no guarantee of success.

In my opinion, FDA’s commitment to solving the DCM riddle bears witness to its dedication to pet health.