The Scoop on Grain Free Diets and Cardiac DiseaseSeptember 18, 2018

Cardiology Notes

The Scoop on Grain Free Diets and Cardiac Disease

Written by Holly B. MacLea, DVM, MS, Practice limited to Cardiology

There has recently been an explosion of information on the internet and social media in regards to grain free diets causing cardiac disease, more specifically dilated cardiac remodeling resembling dilated cardiomyopathy.  This is the beauty of social media in that word travels fast making many aware of potential concerns, but the downside is in determining what is fact and fiction and perpetuating more of the facts than the fiction.  The truth of the matter is that there aren’t currently many facts as much as observations made by veterinary cardiologists across the country.

What is Dilated Cardiomyopathy (DCM)?

Just for review, dilated cardiomyopathy or DCM is a disease that commonly affects large and giant breed dogs and has a genetic component in particular breeds such as Doberman Pinschers, Boxers, Great Danes, and Irish Wolfhounds.  DCM is a disease caused by a decrease in the systolic function or pump function of the heart that over time results in secondary dilation.  The disease can affect both the right and left sides of the heart ultimately resulting in left- or right-sided congestive heart failure.  In addition, many animals with this condition are also at risk to develop arrhythmia that in some cases can be fatal.  This is a disease that can be a primary heart muscle disease but factors aside from cardiac disease have also been shown to secondarily cause decreased cardiac function and dilation including hypothyroidism, tachyarrhythmias, medications, and nutrition in particular breeds (Golden Retrievers and Cocker Spaniels).

Current Observations

What has been observed is an increase in the rates of dilated cardiomyopathy among the common breeds but also in smaller, atypical breeds.  One commonality among these atypical cases seems to be boutique and grain-free diets or diets with exotic ingredients including but not limited to legumes like peas, lentils, chickpeas, and novel proteins sources like duck, salmon, lamb, kangaroo, bison, and venison, and potatoes.  This issue was made known to the US Food and Drug Administration (FDA) Center for Veterinary Medicine.  The following are a few important resources from the FDA website.


What is it about grain free diets that make them potentially lead to cardiac disease?  The truth is that we are unsure but the thought is that some cases are linked to a deficiency in the amino acid taurine.  Back in the 1980’s taurine deficient diets led to increased frequency of DCM in feline patients which has become rare now that commercial pet food companies have included taurine in their diets.  We have known for some time, a link between DCM and taurine deficiency in Cocker Spaniels and more recently a similar link with taurine deficiency and DCM in Golden Retrievers is being examined.

What can Veterinary Professionals do?

It is important to point out that not all animals receiving boutique, grain-free, or exotic ingredient diets will develop cardiac disease.  If your patients are fed these diets and you feel that they are at risk because of breed or develop clinical signs of cardiac disease (tachypnea, dyspnea, exercise intolerance, collapse, coughing), or if clients just want to screen their pets for the presence of cardiac disease, additional testing should be considered.  This includes consultation with a cardiologist for echocardiogram and testing your patient’s whole blood and plasma taurine levels.  The latter is recommended at UC Davis Amino Acid Laboratory:

If low blood taurine levels are identified, taurine supplementation is recommended; however, another key recommendation is diet change, as we have discovered that there may be other factors aside from taurine deficiency in these diets as a cause for development of dilated cardiac remodeling.  The diets that are recommended are those from reputable pet food companies that meet the AAFCO standards, and are formulated by veterinary nutritionists.  I typically recommend brands such as Hills, Science Diet, Iams, Eukanuba, Royal Canin, and Purina; however, there are other boutique diets that meet these criteria so this is just a short list.  Raw, homecooked, or vegetarian diets are not recommended as an alternatives as they can increase the risk of other nutritional deficiencies.

Finally, if you have a patient that has dilated cardiac remodeling and/or low blood taurine levels, please report the information to the FDA.  The more cases and information we can gain the better outcome for all of our pets.  The following is a link to information about reporting:

There is a lot of information so please do not hesitate to reach out with any questions or concerns you may have regarding your patients.  The plan is to periodically update everyone on any changes or discoveries so please stay tuned!

About the Author

Holly B. MacLea, DVM, MS, Practice limited to Cardiology

Holly B. MacLea, DVM, MSDr. Holly MacLea is a native of Pottsville, Pennsylvania.  She completed her undergraduate studies at the University of New Hampshire in 2000.  She spent several years working as a research assistant at Dartmouth Medical School prior to attending veterinary school at Michigan State University College of Veterinary Medicine.  Following graduation in 2007, she completed a rotating internship in small animal medicine and surgery at VCA Newark Animal Hospital in Delaware followed by a specialty internship in internal medicine and emergency and critical care at VCA Veterinary Specialty Center of Indiana. Realizing a passion for cardiology, she went on to complete a 3-year residency program in cardiology at Colorado State University while also obtaining a masters degree in clinical sciences.  Following completion of her training in 2012, Dr. MacLea worked as a staff cardiologist at VCA Northwest Veterinary Specialists in Portland, OR for 2 years prior to returning back to the east coast and New England to be closer to family.  Most recently she was a staff cardiologist at VCA CAVES in Concord, NH.

Dr. MacLea is excited to join the team at Port City Veterinary Referral Hospital.  Special interests in cardiology include management of all stages of congestive heart failure, degenerative mitral valve disease, echocardiography, and congenital heart disease.  She is trained in minimally-invasive surgical techniques (transvenous pacemaker implantation, patent ductus arteriosus occlusion, balloon valvuloplasty) and is hoping one day to bring these interventional techniques to her patients at Port City and the seacoast area.   Dr. MacLea is especially committed to not only working with animals but with their owners and believes that good client education is essential to providing the best care for her patients to allow them to live longer and happier lives with their heart disease.

Aside from veterinary cardiology, Dr. MacLea enjoys the adventure of raising her twins, any and all outdoor activities, baking, and being crafty.  In addition she loves spending time with her adorable miniature, longhaired dachshunds Gunter and Klaus and her husband Kyle (also adorable).

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