There has been a lot of recent discussion in the veterinary community on the topic of grain free diets and heart disease. To help get to the bottom of the problem, the Journal of the American Veterinary Medical Association (JAVMA) did an overview of concerning reports that veterinary cardiologists were seeing a rise in heart conditions in dogs fed grain free diets and I thought that I would outline the information in the article to help look at the complex interactions in this issue.
What is Dilated Cardiomyopathy?
Dilated Cardiomyopathy is the most commonly reported cardiac condition in large breed dogs. In this condition, degeneration of the heart muscles leads to thinning of the walls of the heart and stretching of the heart causing an increase in heart size. As heart size increases blood pressure changes and fluid begins to build up within the lungs and abdominal cavity causing coughing, difficulty breathing and lethargy. Breeds that are affected include Boxers, Dobermans, and Great Danes and less commonly German Shepherd Dogs and some medium sized breeds such as Cocker Spaniels, English Springer Spaniels
According to the JAVMA report, veterinary cardiologists have recently noticed that they were diagnosing dilated cardiomyopathy in Golden Retrievers at higher rates than expected and seeing the condition in dogs of breeds typically not thought to be prone. Subjectively, it also appeared that these dogs were frequently eating diets containing exotic ingredients such as kangaroo, duck, buffalo, salmon, lamb, bison, venison, lentils, peas, fava beans, tapioca, barley, or chickpeas as major ingredients. Research began to see if the two were related. Since the 1990’s it has been well established that dietary deficiency in the amino acid Taurine could predispose cats and dogs to developing dilated cardiomyopathy. Could this be the cause? A study was done evaluating 24 Golden Retrievers eating exotic diets who had confirmed dilated cardiomyopathy and confirmed low blood levels of taurine. All but 1 dog had substantial improvement in their heart condition with diet change and addition of taurine.
What does all of this mean?
Nutrient standards exist for pet foods and any commercial product must meet these standards (including levels of taurine) in order to be sold, so why are we seeing deficiencies in dogs fed diets with these exotic ingredients? The study authors list a number of theories but the major hypothesis is that exotic ingredients (such as lentils, peas, fava beans, tapioca, barley, or chickpeas) used to replace traditional grains have different nutritional profiles and different digestibility than more common ingredients and have the potential to affect the metabolism of other nutrients. So although the taurine is in the food, the dogs cannot digest it properly and deficiencies are created leading to heart disease. Investigation is ongoing. What is clear is that diet change and taurine supplementation improved the heart condition of the dogs in the study.
To further complicate the picture, there were also study dogs who did not have low blood levels of taurine, but whose heart disease also improved with diet change and taurine supplementation. Research is ongoing in this area as well to see if an unknown factor is influencing heart disease in these dogs. Clearly there is a complex relationship between exotic ingredients and heart disease in dogs.
So, what is the the take away from all of this?
My golden retriever is eating a grain free diet and seems to be doing well, what should I do? What if my dog is a Doberman on a grain free diet? Or a Dachshund? Unfortunately there is no clear choice that will be right for everyone. Choosing the right diet for dogs is difficult today with all of the options, marketing and opinions that are available from different sources. I will say that actual documented cases of grain allergies in pets that would necessitate a grain-free diet are rare.
When I choose a pet food, I like to know that the diet is formulated by a veterinary nutritionist, made by the company in their own facility, that they are doing their own research and development on their foods and that the food has undergone feeding trials to show that it will provide the nutrition it claims without side effects. To me, the case of grain free diets and heart disease shows the importance of ensuring that the foods we are feeding have been through feeding trials and unfortunately most foods on the market today have not had this important safety step performed. If you have concerns about the food you are feeding to your dog, ask the company that makes it for the information listed above; You may be surprised by the answers you get. And if you have any concerns about your pet’s health including any possible heart condition that they may be suffering from, get them in to see us so that we can give them a complete checkup.
Lots to think about. Please feel free to get in touch with our staff and we will help you to make the right choice for you and your pets
-Dr. Rob Hillerby
For more information, see the links below
https://vetnutrition.tufts.edu/2018/11/dcm-update/
https://caledonvet.com/wp-content/uploads/2019/05/selecting-the-best-food-for-your-pet.pdf
