What is Diet-associated Cardiomyopathy?
First let me start by defining DCM. DCM stands for dilated cardiomyopathy, a disease in which the muscles of the heart are unable to beat effectively, resulting in an enlarged, or dilated, heart. DCM is characterized by weakness, slowing down, decreased ability to exercise, shortness of breath, coughing, or fainting and can result in abnormal heart rhythms, congestive heart failure, and sudden death. It is most typically seen in large and giant breed dogs, such as Doberman Pinchers, Boxers, Irish Wolfhounds, and Great Danes, where it is thought to be genetically linked.
Recently, however, veterinary cardiologists have begun to see an increase in DCM cases, both in dogs traditionally predisposed to DCM, as well as breeds not typically associated with DCM, such as small and mixed breed dogs. It soon became apparent that there was a nutritional correlation between these cases and the FDA, along with board certified veterinarians, began to study what is now being termed “Diet-Associated DCM”.
What is Taurine and What Role Does It Play?
Taurine is an amino acid that is critical for normal heart function. Taurine deficiency was first associated with DCM in cats back in 1987. While some of the dogs currently diagnosed with Diet-Associated DCM do have low levels of taurine in their blood, we are also seeing numerous cases in dogs with normal taurine levels. Some experts are theorizing that something in the these dogs’ diets may be blocking or interrupting proper taurine metabolism, thus resulting in DCM. What is especially important to note is that the majority of dogs who are diagnosed with Diet-Associated DCM do NOT have low taurine levels, indicated that taurine supplementation is likely ineffective at preventing this disease.
What Diets are Implicated?
As we do not yet know the exact cause, it’s difficult to pinpoint specific diets as the culprit. Current thinking is that BEG diets (boutique companies, exotic ingredients and grain-free diets) are the cause. These BEG diets are generally made by manufacturers who lack a thorough understanding of the methodology of pet food manufacturing and the way nutrients interact with one another. There appear to be several problematic ingredients that are popular in these diets, including but not limited to legumes, potatoes, and other “exotic” ingredients. Dogs being fed unconventional diets (vegan, vegetarian, raw and homemade diets) are also being diagnosed with Diet-Associated Dilated Cardiomyopathy and, as such, feeding a vegan, vegetarian, raw or homemade diet is not a safe alternative. In June of 2019, the FDA released an update on Diet-Associated Dilated Cardiomyopathy, informing owners of the most reported brands, specifically:
- Taste of the Wild
- Earthborn Holistic
- Blue Buffalo
- Nature’s Domain
- California Natural
- Natural Balance
- Nature’s Variety
- Rachael Ray Nutrish
What Diets are Recommended?
Selecting a pet food in today’s market can be quite daunting. Marketing plays an enormous role and often overshadows good nutrition. Labels are confusing and often contain useless information, the sole purpose of which is to appeal to consumers. Furthermore, ingredient lists by themselves are of little value as it is the nutrients contained within those ingredients, how they are metabolized, how they interact with one another, and how they respond to processing, that are true concerns. For more information about ingredients lists, please read Dr. Lisa Freeman’s article “Deciphering Fact From Fiction: Evaluating a Pet Food Ingredient List “.
At this point, most veterinarians, veterinary cardiologists and veterinary nutritionists recommend the WSAVA (World Small Animal Veterinary Association) Global Nutrition Committees Recommendations on Selecting Pet Food. These recommendations are as follows:
- The company must employ at least one full-time nutritionists (either a Phd in animal nutrition or a board-certified veterinary nutritionist).
- The company’s diets must be formulated by nutritionists who are qualified at the highest levels (PhD in animal nutrition or a board-certified veterinary nutritionist).
- Prior to release, the company’s diets must be tested using AAFCO (Association of American Feed Control Officials) approved feeding trials.
- The company diets must be manufactured in their own plants.
- The company must have strict quality control measures in place to evaluate each diet at several points throughout the manufacturing process, as well as strict quality control and criteria to evaluate all ingredients and suppliers.
- The company must provide a complete nutrient analysis for any diet in question (complete nutrient analyses are far more information than average or typical analysis and should provide you with an exact number in grams per 100 kilocalories rather than an as fed or dry matter percentage).
- The company must be able to provide caloric value per gram, can or cup of food for each diet manufactured.
- The company should have a dedication to veterinary nutritional research with publications in peer-reviewed journals.
When all is said and done, there are only 3 U.S. pet food brands that satisfy all criteria: Hill’s Science Diet, Purina ProPlan/Purina One, Eukanuba, and Royal Canin.
My Dog Has Been Eating BEG/Unconventional Diet, What Should I Do?
The most recent recommendations are to start with taurine testing (both whole blood and plasma) and an echocardiogram (heart ultrasound). While most dogs with Diet- Associated DCM have normal blood taurine diets, it is still helpful to gather information as to which diets are resulting in low blood taurine levels so that we may better understand the causative agents behind this devastating disease. However, most cases of DCM do not cause heart murmurs or cardiac arrhythmias until much later during the course of disease. It is, therefore, recommended that your also dog have an echocardiogram performed to look for signs of DCM prior to the onset of clinical signs. It may also be that a blood test, known as a cardiac proBNP, may be helpful in screening dogs for Diet-Associated DCM but more research is needed at this time in order to determine the reliability of such a test.
Once these diagnostic tests have been completed, it is then recommend that you begin a slow transition to one of the brands that meets all of the WSAVA criteria. As in all things pet related, please contact your veterinarian for specific concerns regarding your own pet(s).