Updated: Feb 16, 2019
Heart disease is common in our companion animals, affecting 10-15% of all dogs and cats, with even higher rates in Cavalier King Charles Spaniels, Doberman Pinschers, and Boxer dogs. Most nutritional recommendations focus on treating dogs and cats with heart disease and there is much less information on the role of diet in causing heart disease. However, a recent increase in heart disease in dogs eating certain types of diets may shed light on the role of diet in causing heart disease. It appears that diet may be increasing dogs’ risk for heart disease because owners have fallen victim to the many myths and misperceptions about pet food.
Recently, the FDA released a warning to Veterinarians and pet owners about reports of and increase Dilated Cardiomyopathy (DCM) cases being seen in dogs eating grain free or boutique dog foods. This report definitely is a cause for concern because it shows that DCM is occurring more frequently in dogs that are NOT are not considered to be genetically predisposed to DCM such as: Golden Retrievers, Labrador Retrievers, Shih Tzu, Bulldogs, and Miniature Schnauzers.
The most common genetically predisposed breed include: Great Dane, Irish Wolfhounds, Doberman Pinscher, and Boxer Dog.
What is DCM?
DCM is a disease of the heart muscle that results in weakened contractions and poor pumping ability. As the disease progresses the heart chambers become enlarged, one or more heart valves may leak, and signs of congestive heart failure develop.
Early in the disease process there may be no clinical sign detectable, or the pet may show reduced exercise tolerance. In some cases, a heart murmur (usually soft), other abnormal heart sounds, and/or irregular heart rhythm is detected by your veterinarian on physical examination. Such findings are more likely as the disease progresses.
As the heart’s pumping ability worsens, blood pressure starts to increase in the veins behind one or both sides of the heart. Lung (pulmonary) congestion and fluid accumulation (edema) often develop behind the left ventricle/atrium. Fluid also may accumulate in the abdomen (ascites) or around the lungs (pleural effusion) if the right side of the heart is also diseased. When congestion, edema and/or effusions occur, heart failure is present. Weakness, fainting episodes, and unfortunately, sudden death can result from heart rhythm disturbances.
Possible link to DCM
Back in the late 1980's, DCM was seen very commonly in cats. It was found that diets were deficient in an amino acid called Taurine. Thankfully, the condition was reversible with taurine supplementation. Now, most reputable commercial food brands contain enough taurine in the diet to prevent DCM from occurring.
The number of dogs with taurine deficiency and DCM appeared to decrease since the early 2000’s. However, recently, some cardiologists are noticing higher rates of DCM in some atypical dog breeds. They also noticed that both the typical and atypical breeds were more likely to be eating boutique or grain-free diets, and diets with exotic ingredients such as: kangaroo, lentils, duck, pea, fava bean, buffalo, tapioca, salmon, lamb, barley, bison, venison, and chickpeas. Even some vegan diets have been associated. It has even been seen in dogs eating raw or home-prepared diets. It is thought that these foods may lack sufficient amounts of taurine.
Are these foods actually better?
As a Veterinarian in clinical practice, I can attest to the notion of most pet owners are feeding grain free and boutique foods but are these foods actually better for your dog? The food companies are marketing that these exotic ingredients are healthier for dogs than the traditional ingredients.
There is absolutely no truth to this marketing technique and many pet owners are falling victim to the "grain free myth". There is currently no evidence showing that these exotic ingredients are healthier for dogs. It is simply effective marketing that is preying on a pet owner's desire to provide the healthiest diet possible for their pet.
Many diets that include grains are being slammed all over the internet for being a primary cause of food allergies in pets. The fact is that food allergies are very uncommon so there is no benefit to feeding these diets containing the exotic ingredients. Veterinary nutritionists continuously reemphasize that grains do NOT cause any specific health problems for pets and are actually a good source of protein, vitamins, and minerals.
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, less able to exercise, short of breath, coughing, or fainting. Your veterinarian will listen for a heart murmur or abnormal heart rhythm and may do additional tests (or send you to see a veterinary cardiologist), such as x-rays, blood tests, electrocardiogram, or ultrasound of the heart (echocardiogram).
Do yourself a favor and stop reading the ingredient list! This is by far the most common way pet owners select their pets’ food, but it is the least reliable way to do so. Be careful about currently available websites that rank pet foods either on opinion or on based on myths and subjective information. It’s important to use more objective criteria (e.g., research, nutritional expertise, quality control in judging a pet food). The best way to select what is really the best food for your pet is to ensure the manufacturer has excellent nutritional expertise and rigorous quality control standards (AAFCO feeding standards). Don't let yourself be fooled by the clever marketing. Your dog's heart depends on it.
Published by Dr. Mason Romero, DVM