Upstate Veterinary Specialties take on Diet-Associated Dilated Cardiomyopathy

February 14th, 2019 | Posted in General, Medical Articles

Dear Colleagues,

Recent evidence has led the US FDA to announce that diets including legumes, lentils, peas and potatoes as main ingredients may be linked to the development of dilated cardiomyopathy (DCM) in dogs. Typically, most of these diets are marketed as “grain-free”. This has led to a lot of concern, confusion and frequent questions from our clients, the general public and our referring veterinary community. We thought we would reach out and briefly discuss what we know, what we don’t, and how we are proceeding with this information.

Reports in the past linked taurine deficiency to DCM in specific breeds of dogs such as Golden Retrievers and Cocker Spaniels. Performing whole blood taurine level testing for those breeds was routinely recommended if a diagnosis of DCM was made. Lamb based diets were considered potential at-risk diets, specifically for the Golden Retriever.

With the advent of the boutique and grain-free diets, we are now seeing DCM much more commonly in atypical breeds and it seems it is more complicated than simply taurine deficiency. There is now a group of dogs that are atypical breeds, have taurine levels that are within normal limits, develop DCM, and then show echocardiographic and clinical improvement after a change to a standard diet. It is not clear whether this is due to a specific nutritional deficiency or due to a cardiotoxic ingredient that has not yet been discovered.¹

Golden Retrievers appear to be particularly sensitive to taurine deficiency and based on work by Dr. Josh Stern (DACVIM) at UC Davis these dogs may develop DCM in the low end of the classic normal range for blood taurine. Any atypical breed, or any dog eating a boutique or grain-free diet, should have blood taurine levels performed. The current recommendation is to perform concurrent plasma and whole blood taurine levels. However, due to the cost we typically perform whole blood taurine levels, as this has classically been thought to be a better indicator of long-term myocardial taurine.¹

This has certainly been a challenging situation for us. Clients who have been feeding these diets, which are expensive and touted as “healthier” than all typical commercial and prescription diets, are some of the most dedicated pet owners. To be clear, not all dogs who are fed these diets will develop DCM, there are likely other factors, whether genetic or otherwise, that we have yet to discover or understand. Our recommendations have been as follows.

If we have a dog with confirmed DCM by echocardiography eating a grain free diet or diet with the above main ingredients, or an atypical protein source, we recommend testing for whole blood (+/- plasma) taurine levels. We start standard therapy with pimobendan +/- congestive heart failure therapy as clinically indicated. If diet associated DCM is possible, even if taurine levels are within normal limits, a diet change is recommended. We recommend changing the diet to one with standard ingredients from a well-established manufacturer that does not contain peas (or pea products), legumes (lentils, chick peas, etc), or potatoes as one of the top 5 ingredients in the diet. One consideration is the Tufts Cummings School of Veterinary Medicine “HeartSmart” website that includes low-sodium diet options with standard ingredients: http://vetmed.tufts.edu/heartsmart/diet/reduced-sodium-diet-and-treat-lists-for-pets-with-heart-disease/.

We recommend taurine supplementation for all dogs with echocardiographically confirmed DCM and proven taurine deficiency. If an owner is interested in a home-made diet, we recommend consultation with a veterinary nutritionist. Another supplement that is recommended by some cardiologists is L-carnitine supplementation, which has benefits for myocardial energy production.

If a client is feeding one of the diets of concern but their dog does not have echocardiographic evidence of DCM, we are still recommending a diet change, especially if their dog already has another cardiac disease (such as myxomatous valve disease). We feel it is not worth the risk to continue feeding the diet when we are still in the infancy of understanding this problem. We suggest diet selection could be made based on the recommendations of the WSAVA (The World Small Animal Veterinary Association) Global Nutrition Committee: https://www.wsava.org/WSAVA/media/Arpita-and-Emma-editorial/Selecting-the-Best-Food-for-your-Pet.pdf

If a dog is identified to have a low blood taurine level, and/or has echocardiographic evidence of DCM we would urge that this be reported to the FDA, the guidelines can be found here: https://www.fda.gov/AnimalVeterinary/SafetyHealth/ReportaProblem/ucm182403.htm

Sincerely,

Your Cardiology Team at Upstate Veterinary Specialties,
Agnieszka Kent, DVM, MS, DACVIM
Cassidy Sedacca, MS, DVM, DACVIM
Aaron Wey, DVM, DACVIM

References:

¹Freeman et al. Diet-associated dilated cardiomyopathy in dogs: what do we know? J Am Vet Med Assoc. 2018;253:1390-1394