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Adam Scott Contemplates the Link Between Diet, Heart Disease

The question about the link between heart disease and diet has become a common conversation at my hospital since the FDA released a warning statement. This link is still under investigation, and as a result, there are still many uncertainties surrounding this topic; however, there are new findings that might help you choose an appropriate diet for your pet.

The FDA issued a statement citing a link between certain foods and a type of heart disease known as Dilated Cardiomyopathy, or DCM. This statement comes from multiple recent studies where a significant number of dogs diagnosed with DCM had been fed diets categorized as “boutique (small manufacturer), exotic ingredient (nontraditional protein sources), or grain-free (BEG diets).” After switching diets, many of these dogs’ heart condition improved. Further studies are still underway to better evaluate this correlation, but at this time we have enough information to justify avoiding these types of diets.

Dilated Cardiomyopathy is a heart disease leading to weakening of the heart muscle, and as it progresses can lead to heart failure, a life-threatening issue. Cases of DCM have been on the rise in recent years, which has lead researchers to examine possible contributing factors. These studies explore possible reasons for this link, and an active area of research revolves around levels of the amino acid taurine. In these studies, some dogs had low blood levels of taurine, which has been known to cause DCM in cats; however, not all dogs were found to be low in taurine, making this a more complicated matter than just supplementing taurine to these diets.

The apparent link between BEG diets and DCM is speculated to be due to ingredients used to replace grains in grain-free diets, such as lentils or chickpeas, but also may be due to other common ingredients commonly found in BEG diets, such as exotic meats, vegetables, and fruits. Another thought is that something in these diets actually has a toxic effect on the heart muscle itself. The exact relationship is yet to be understood and further studies are underway.

Over the past few years, the number of dogs on grain-free diets has risen exponentially, and many people may be reluctant to switch from one of these diets. In actuality, a common issue is the misunderstanding that grain is bad for dogs. Contrary to popular belief and marketing, there are no health benefits of grain-free or exotic ingredient diets except in the rare case of food allergy. The vast majority of food allergies are instead due to the protein source. As a result, there is no real evidence that these types of diets offer any positive benefits.

Many well-intentioned pet owners are choosing to switch to a home-cooked diet or raw diet as a result of this information. Unfortunately, these types of diets may pose a risk as well. As a result, I recommend feeding a commercial pet food from a well-established manufacturer that contains common ingredients including grains. If your pet requires a home-cooked diet for a medical condition, I recommend consulting a veterinary nutritionist to properly formulate this diet so that it contains all necessary nutrients.

After discussing this topic with pet owners, the next question is what specific diet should my pet be fed. Well, this is a whole separate topic and varies from pet to pet, and I strongly recommend having this conversation with your veterinarian. With that said, one key factor to look for is whether a diet has been tested with Association of American Feed Control Officials, or AAFCO, feeding trials. (This information also can be found on the label). If AAFCO feeding trials are not conducted, the manufacturer should at least ensure their diets meet AAFCO nutrient profiles through analysis of the finished product.

In summary, UC Davis Veterinary Cardiology service has recommended a few key steps with regards to this issue that I would like to share.

• Evaluate the diet that you are feeding your pet. If the diet is boutique, contains exotic ingredients, or is grain free, you may consider a diet change to one without these properties.

• If you are concerned about your dog based on what you are feeding, watch closely for signs of heart disease such as weakness, slowing down on walks, coughing, fainting, or trouble breathing. Your veterinarian may also recognize early heart disease by hearing a heart murmur or abnormal heart rhythms.

• If your dog is diagnosed with DCM, particularly if eating a diet that meets the criteria listed above, ask your vet about further steps that can be taken to test and treat the disease based on this information.

There is still so much to be learned about the connection of heart disease and what you feed your pet. More information is likely on its way, so this is a great conversation to have with your veterinarian at your pet’s next wellness exam.

Adam Scott, DVM, practices at Bishop Ranch Veterinary Center & Urgent Care, WebVets.com, in San Ramon. He is a graduate of the Veterinary School at the University of California, Davis. 

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