LAMORINDA WEEKLY | One year later - What do we know about grain-free food investigation?


Dr. Mona Miller lives in Lafayette with her son, two cats and yellow Labrador. She attended UC Berkeley as an undergraduate, and received her DVM from UC Davis. She has been happy to call Lafayette home since 2001. She can be reached via email at MonaSDVM@aol.com. She welcomes questions from readers that may get incorporated into a column.

It has been 16 months since the U.S. Food and Drug Administration first publicly alerted pet owners about its investigation of the potential connection between grain-free dog foods and a particular form of heart failure. I wrote about this issue in the Aug. 22, 2018 edition of the Lamorinda Weekly. The potential connection - which I believe we can now consider real - appears to be the link between some boutique pet foods that are "grain-free" and taurine deficiency in the affected dogs. Taurine is an amino acid that is often found in meat and fish. It is essential for health of heart muscle, other skeletal muscle, retina and the central nervous system. This taurine-deficient heart disease linked to grain-free foods results in a specific type of heart muscle problem, called Dilated Cardiomyopathy. With DCM, the heart muscle is too floppy to contract well, and dogs go into heart failure fairly quickly.

The FDA first received a few reports in early 2014. After its initial public alert in July 2018, the numbers spiked and the vast majority of cases have been reported since then. There have been 560 cases in dogs reported, and 14 in cats. The mortality rate appears to be 20% for dog and 35% for cats. By all accounts, this is affecting a very small number of pets eating grain-free diets. However, as I tell my clients, no one wants their own dog to be included in this count, in what might very well be a preventable problem.

So, with three reports released by the FDA, and about 560 dogs reported, what do we know now? First, there appears to be no genetic or breed predisposition. A large variety of dog breeds have been reported, with Golden Retrievers as the number one breed, and "mixed breed" in the number two spot. There have also been a variety of ages and weights, spanning the ranges of young to senior, and small to giant breeds.

More Golden Retrievers have been reported, but this is thought to be due to increased awareness among Golden Retriever social media forums. Breed-specific groups and activities are often more successful in encouraging owners to seek and finance specific diagnostic tests and work with their veterinarians to search for a diagnosis.

With respect to the types of diets involved, FDA's latest report in June provided the names of 16 brands of food that were named 10 times or more. The most common formulation was dry food (with 452 cases), but other formulations included raw, semi-moist and "other." Of the diets reported, more than 90% are classified as "grain-free" and 93% contained peas and/or lentils. A variety of protein sources were found in the diet, and no one type was found as dominant.

Tests for mineral and heavy metal compounds in the diets did not show any abnormalities. Likewise, several amino acids were checked for, including taurine, and no abnormalities were found (thus, the diets themselves were not taurine-deficient). The FDA is still investigating if there is altered taurine metabolism in the affected dogs.

To date, the FDA investigation has not reached any conclusions, and continues to seek collaboration with veterinarians and owners. Additionally, UC Davis School of Veterinary Medicine is actively participating in related studies, including looking for biomarkers of taurine metabolism.

What can dog owners do? Discuss this issue with your veterinarian at your dog's next wellness exam, especially if he is on a grain-free food. Some dogs are on a grain-free food because of a medical condition (skin or gut issues that seem responsive). But most dogs on grain-free foods, in my opinion, do not have a specific health problem that warrants these boutique diets. In these dogs, if there is no evidence of heart disease, then I recommend to my clients that the dog be transitioned to 25-50% grain-containing food, with minimal amount of peas/lentils, within a one-month timeframe. If a murmur is heard, then further tests are definitely indicated, including blood levels of taurine and heart muscle enzyme. Additional tests such as radiographs or ultrasound of the heart might also be indicated. This is a possibly preventable health problem in dogs, and definitely warrants further discussion with your veterinarian.

The following websites are useful resources:

http://lamorindaweekly.com/archive/issue1213/Grain-free-doesnt-mean-problem-free.html

https://www.fda.gov/animal-veterinary/news-events/fda-investigation-potential-link-between

-certain-diets-and-canine-dilated-cardiomyopathy

https://veterinarypartner.vin.com/default.aspx?pid=19239&id=8989590

https://ccah.vetmed.ucdavis.edu/sites/g/files/dgvnsk4586/files/inline-files/UPDATEOct2019ucd

-diet-and-dcm-handout_0.pdf