The Link Between Grain-Free Diets and Heart Disease in Dogs
Pet food is a frequent topic of conversation among pet owners and veterinarians. What should I feed my dog? Dry kibble? Canned food? What about a raw diet? Or homemade diet? We all want to make the best decision for our animals and give them the best nutrients possible, but if you have read anything about pet food recently, you know that isn’t so easy to do. Honestly, as a veterinarian, I find it difficult to give pet parents a solid diet recommendation. I know the best diet is one that is well balanced with all of the necessary vitamins and minerals a dog needs; however, not every dog food provides this (despite its claims). Pet food is not well regulated in the USA (a topic for another blog post), but there have been constant recalls on dog (and cat!) food which causes frustration among veterinarians and pet parents alike. However, there is a new and very serious concern emerging among dog food: heart disease. That’s right, foods pet parents felt were the best possible option on the market have been linked to heart disease in dogs. Sure, heart disease occurs in dogs of all sizes, but the type of heart disease we are seeing linked to the diet is dilated cardiomyopathy (enlarged heart) which is typically a disease of large to giant breed dogs. The dogs who have been affected are dogs of all sizes and have been consuming boutique diets labeled as gluten-free and containing exotic ingredients such as chick peas, sweet potato, and lentils. Cardiologists are studying these cases very closely to determine the cause and how to best advise pet parents and veterinarians.
I have received several inquiries regarding pet food and the grain-free debate so I reached out to a friend and colleague of mine, veterinary cardiologist, Dr. Herb Maisenbacher, to give us all an update on the link between grain-free diets and heart disease in dogs.
Veterinary cardiologists have reported an increase in the diagnosis of a specific heart disease, called dilated cardiomyopathy (DCM), in dogs eating grain-free diets, as well as exotic ingredient (kangaroo, lentil, duck, pea, salmon, chickpea, etc.) and boutique diets (Boutique, Exotic ingredient, and Grain-free = BEG). DCM is a serious and life-threatening heart disease in which the heart muscle loses its ability to contract forcefully and the cardiac chambers enlarge. This can lead to arrhythmias (irregular heartbeats), congestive heart failure, and death. Now, certain dog breeds (Doberman Pinschers, Great Danes, Boxers, Irish Wolfhounds, and Newfoundlands) are predisposed to DCM and it is not surprising to diagnosis the disease in them (regardless of their diet). But the cases of heart disease associated with BEG diets have been diagnosed in non-predisposed breeds, such as Golden and Labrador Retrievers, Whippets, Shih Tzus, Miniature Schnauzers, Boston Terriers, and even mixed breed dogs. But what is it about these BEG diets that is causing enlarged hearts in these dogs?
Well, it has been known for several decades that deficiency of a specific amino acid called taurine can cause DCM in dogs and cats. Many of the dogs with BEG diet associated DCM have been tested for blood taurine levels and while some have been taurine deficient, some have not, so taurine deficiency cannot explain all of these cases. Some dogs have had improvement in heart size and function with diet change and taurine supplementation, but not all have. The actual cause or causes of BEG diet associated DCM are not known, but research is already being done by veterinary cardiologists and nutritionists from North Carolina State to UC Davis. It could be that the diets are missing a component necessary for normal cardiac function, contain an ingredient that interferes with cardiac function, or that there are different problems with different diets. This problem is concerning enough that the FDA has posted warnings about the association between BEG diets and DCM (https://www.fda.gov/AnimalVeterinary/NewsEvents/CVMUpdates/ucm613305.htm and https://www.fda.gov/AnimalVeterinary/ResourcesforYou/AnimalHealthLiteracy/ucm616279.htm ), and possible cases should be reported to them (How to Report a Pet Food Complaint - https://www.fda.gov/AnimalVeterinary/SafetyHealth/ReportaProblem/ucm182403.htm).
At this time, veterinarians are recommending that dogs not be fed BEG diets. With all of the pet food brands available, it is difficult to recommend any specific diet, but whatever diet you choose, it should meet the World Small Animal Veterinary Association (WSAVA) guidelines (https://www.wsava.org/WSAVA/media/Arpita-and-Emma-editorial/Selecting-the-Best-Food-for-your-Pet.pdf). Manufacturers that meet these guidelines, not only produce foods that meet Association of American Feed Control Officials (AAFCO) nutrient profiles, but also employ full time veterinary nutritionists, have specific quality control measures in place, and often do prospective feeding trials to be sure that feeding a specific diet will lead to healthy pets.
For more information about BEG diet associated DCM, read this article written by Dr. Freeman, a board-certified veterinary nutritionist at Tufts University (http://vetnutrition.tufts.edu/2018/06/a-broken-heart-risk-of-heart-disease-in-boutique-or-grain-free-diets-and-exotic-ingredients/).
If you are currently feeding your dog a BEG diet, please have a conversation with your veterinarian to discuss the best diet option for your dog.
– Herbert Maisenbacher, DVM
Dr. Herb Maisenbacher is an ACVIM board-certified veterinary cardiologist. He was a Clinical Assistant Professor at the University of Florida College of Veterinary Medicine prior to starting his practice, Veterinary Heart Care, in Virginia Beach, VA.