Recent news about a possible link between diet and a particular form of heart disease has drawn more attention to a longstanding problem in our beloved goldens. Social media has been loaded recently with mention of grain free diets being bad for the canine heart and warnings to stop feeding diets of that type. Whether or not grain free is beneficial or necessary is the subject for another post. For now, let's look at this current news. The concern about diet and a form of heart disease referred to as dilated cardiomyopathy (DCM) actually has a history dating back to the early 1980s with research ongoing since that time. Recognition of DCM occurring in some unique circumstances recently has led to new attention being given to this condition and a possible connection to diet. Golden retrievers are one of the breeds that may be predisposed to developing this dreadful condition. Let’s take a look at the heart disease part of this story and then the dietary component.
In dilated cardiomyopathy, the heart enlarges (dilated) which makes the heart (cardio) muscles (myo) damaged or sick (pathy). A simple description of this condition is that the muscles of the heart enlarge which causes them to weaken. As a result, the heart does not pump properly. That leads to poor circulation of the blood throughout the body and the kind of damage you would expect with a poorly functioning heart. If you are familiar with heart failure in people, the process and outcome is the same in dogs. The heart has to work harder yet it continues to be less effective as it pumps. Fluid builds up in the lungs and other body parts, and a dangerous process leading to heart failure ensues. The valves in the heart may start to leak and the dog starts to show the same signs of congestive heart failure that we see in people.
Early in this process there may be no symptoms, or the dog may seem to tire more easily, pant more, or not tolerate exercise as well. Your veterinarian may notice a heart murmur. As the disease progresses, there can be episodes of coughing, panting or heavier breathing, weakness or fainting. The dog becomes at risk of sudden death without treatment or if activity is not moderated. The heart may develop an abnormal rhythm which can lead to sudden death even without the other symptoms. Proper diagnosis and early intervention are critical to at least slow progression to heart failure and minimize the risk of sudden death. Treatment is very similar to treatment of humans with heart failure and includes medication and activity restriction. The disease usually is progressive, meaning it will continue to get worse. Medication can slow the progression, but it cannot restore a healthy heart.
A particular array of amino acids is critical to healthy heart muscle as well as to other body components and functions. Taurine is an amino acid that is especially important in cardiac function and is the amino acid of concern with the possible link between diet and DCM. Dogs usually can create taurine from other amino acids so it is not typically added to prepared foods. Cats cannot, so it is common to see taurine on the list of ingredients on cat food labels. Some dogs have problems synthesizing taurine, however, and there is evidence that golden retrievers, at least some of them, may be genetically predisposed to an inability to synthesize this important amino acid. That means they need to get it through their diet or through supplements.
Over the last decade or so there has been some evidence of a possible link between DCM and diet especially for animals who cannot manufacture taurine. There are a couple of factors at play in this scenario. One is the use of “exotic” (uncommon) meats in diets with the meat sources possibly being deficient in the components that dogs need to manufacture taurine. The other factor is the substitution of protein sources in some diets with ingredients that do not provide the necessary amino acids. It is not the fact that a diet is grain free that is the problem but the ingredients overall that are included in many diets. Home prepared meals have been implicated in diets linked to DCM as well as some commercial preparations. Foods that include peas, potatoes, lentils, and legumes as some of the first ingredients are thought to be particularly troublesome in regard to taurine deficiency whether the diet is grain free or not. There is some early research showing that diets that are high in carbohydrates may displace amino acids or may interfere with taurine absorption.
So, what do we do to protect our beloved companions? In time, research will give us better answers including dietary recommendations. In a future post, I will be writing about how to choose a good food for your dog. The good news in this situation is that DCM due solely to taurine deficiency might be reversible if caught early. There are some dogs with normal blood taurine levels, however, who still are at risk for DCM. What we know at present about golden retriever health tells us it is a good idea to do the following: If feeding a prepared food, make sure it is a high quality, balanced, AAFCO certified food from a reputable company and distributor. Read the ingredient label and make sure a quality protein is the first ingredient listed. Typically this will be some form of meat, fish, or eggs. Keep up with visits to your veterinarian, annually at minimum. As your dog ages, twice a year visits may be appropriate. Be observant for signs of activity intolerance such as your dog becoming tired more easily, a cough especially related to activity, or excess panting. Sometimes the cough will be more of a soft, throat-clearing sound than a harsh cough. These can be early signs of many conditions with heart disease being among the possibilities. See your vet as soon as you can if you notice any of these signs. During routine visits, talk with your vet and determine if any diagnostic tests are warranted for your dog related to DCM and other conditions common in golden retrievers. If your veterinarian detects a murmur or has other concerns, be open to the additional diagnostic tests that may be recommended. Since early detection is crucial, it is a good idea to have heart health, including DCM, on your “discuss with my vet” list for an upcoming visit.
Want to read more?
See the original FDA report here
Morris Animal Foundation has funded research in this area. See their news report