By now, many of you have likely heard about the risk of heart disease in dogs eating “BEG” diets – boutique diets from small companies, diets with exotic ingredients, and/or grain-free diets. In July 2018, the FDA announced that they were launching an investigation into the link between these nontraditional canine diets and dilated cardiomyopathy. They published an update on Thursday, June 27, 2019, which can be found here: https://www.fda.gov/animal-veterinary/news-events/fda-investigation-potential-link-between-certain-diets-and-canine-dilated-cardiomyopathy . The following is a recap of what we know so far and details the AERC Cardiology service’s experience.
What is dilated cardiomyopathy?
Dilated cardiomyopathy (DCM) is a serious heart muscle disorder which leads to arrhythmias (irregular heart rhythms that can cause exercise intolerance and fainting), congestive heart failure (an accumulation of fluid in the lungs and/or abdomen, leading to difficulty breathing), and sudden death. In dogs, DCM typically has occurred in large- and giant-breeds and usually is inherited from the dog’s family line. Dobermans, Boxers, Great Danes, and Irish Wolfhounds have been the “poster children” for breeds most commonly affected.
Recently, however, veterinary cardiologists have been seeing significantly higher rates of DCM in nontraditional breeds such as Golden Retrievers. At AERC, we have diagnosed DCM in the following breeds: Golden Retrievers, Australian Shepherds, Border Collies, a Shih Tzu, a Miniature Schnauzer, and even an Icelandic Sheepdog.
What diets are being associated with DCM?
The type of diet that has received the most publicity of late is grain-free; however, what we are seeing is not just limited to grain-free diets. The link between BEG diets (boutique/exotic/grain-free) and DCM may be due to ingredients used to replace grains, such as lentils, peas, chickpeas, and potatoes. However, veterinary cardiologists are also seeing DCM developing in nontraditional breeds eating exotic proteins, such as kangaroo, duck, buffalo, salmon, whitefish, lamb, bison, and venison. A link between lamb and rice diets was initially reported over 15 years ago.
Raw diets are not risk-free either – even some vegan, raw, and home-prepared diets have been linked to DCM. The specific brands of dog food most commonly named in DCM reports submitted to the FDA are Acana, Zignature, Taste of the Wild, 4Health, Earthborn Holistic, Blue Buffalo, Nature’s Domain, Fromm, Merrick, California Natural, Natural Balance, Orijen, Nature’s Variety, NutriSource, Nutro, and Rachael Ray Nutrish.
What is causing nutritional DCM?
In a minority of affected dogs, taurine deficiency appears to be the cause, especially in Golden Retrievers. Taurine deficiency can be diagnosed via a blood test at University of California Davis’ laboratory. An insufficient amount of taurine’s building blocks in the diet, or a reduced absorption of taurine, can lead to taurine deficiency. If caught early enough, dogs who have a diet change and receive supplemental taurine can improve, and the changes in their heart muscle tissue can be reversed.
However, the vast majority of dogs appear to have some other cause of nutritional DCM, as they have normal taurine levels. There could be a separate nutritional deficiency, an ingredient in the food that is toxic to the heart, or the combination of ingredients in the pet food could be causing a reduced absorption of a nutrient, even if that nutrient isn’t technically deficient. The FDA, veterinary cardiologists, and researchers are actively studying the issue to help figure out the cause(s).
At AERC, after over one year of closely monitoring our first few nutritional DCM patients, we are happy to report that we are starting to see full resolution of DCM in our patients that were caught before they entered congestive heart failure. The improvement was achieved, however, after many, many months of cardiac medications, taurine supplementation, and a diet change. Unfortunately, the long-term prognosis is likely to be much more guarded for patients in congestive heart failure, as fibrosis (scar tissue formation) in the heart can be irreversible when it occurs.
What should you do?
If you’re feeding your dog a boutique, grain-free, or exotic ingredient diet, watch for early signs of heart disease – weakness, slowing down, a lower tolerance for exercise, panting, coughing, or fainting. Your veterinarian will listen for a heart murmur or abnormal heart rhythm and may do additional tests such as x-rays, blood tests, electrocardiogram, or ultrasound of the heart (echocardiogram). He or she may also refer you to a veterinary cardiologist.
Change your dog’s diet to a dog food brand that meets the World Small Animal Veterinary Association (WSAVA) criteria. These brands have not just been formulated to meet AAFCO nutritional standards, but have actually been tested in feeding trials, and Dr. Robert George and I, AERC’s cardiologists, have not seen a single case of nutritional dilated cardiomyopathy from any of these brands. Examples include Hill’s Science Diet, Purina Pro Plan, Royal Canin, Iams, and Eukanuba.
Purina, Hill’s and Royal Canin/Mars all have board-certified veterinary nutritionists on staff as well as PhD Animal Scientists and PhD Nutritionists that work throughout various levels of the companies.
Here is a link to WSAVA recommendations in choosing balanced diets for our pets: (https://www.wsava.org/WSAVA/media/Arpita-and-Emma-editorial/Selecting-the-Best-Food-for-your-Pet.pdf)
For more information, please make an appointment with your family veterinarian to discuss this important topic.