Is A Canine Cardiomyopathy Being Created By Crazy Chow?

The eye of the  skeptical cardiologist was caught by an FDA alert issued recently:

FDA Investigating Potential Connection Between Diet and Cases of Canine Heart Disease

According to the alert:

reports of canine dilated cardiomyopathy (DCM) in dogs eating certain pet foods containing peas, lentils, other legume seeds, or potatoes as main ingredients. These reports are unusual because DCM is occurring in breeds not typically genetically prone to the disease.

What Is Dilated Cardiomyopathy?

Dilated cardiomyopathy refers to a disease of the heart muscle characterized by enlargement and global weakness of the main pumping chambers, the ventricles.
The image below is from the echocardiogram of a human with a severe dilated cardiomyopathy.

Humans with DCM experience weakness, shortness of breath and swelling in the legs due to heart failure. Severe cases of DCM are at risk for dying suddenly.

Cardiomyopathy Used To Be A Disease of Large Dogs

According to Lisa Freeman a veterinarian at the Cummings Veterinary Center at Tufts University

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.

Dilated Cardiomypathy in dogs

typically occurs in large- and giant-breeds, such as Doberman pinschers, Boxers, Irish Wolfhounds, and Great Danes, where it is thought to have a genetic component.

The FDA alert indicates that DCM

 is less common in small and medium breed dogs, except American and English Cocker Spaniels. However, the cases that have been reported to the FDA have included Golden and Labrador Retrievers, Whippets, a Shih Tzu, a Bulldog and Miniature Schnauzers, as well as mixed breeds

Is Doggy Dilated Disease Due To Demented Diets?

Writing last year, Dr. Freeman noted that

“In the last few years I’ve seen more cases of nutritional deficiencies due to people feeding unconventional diets, such as unbalanced home-prepared diets, raw diets, vegetarian diets, and boutique commercial pet foods.  The pet food industry is a competitive one, with more and more companies joining the market every year.  Marketing is a powerful tool for selling pet foods and has initiated and expanded fads, that are unsupported by nutritional science, including grain-free and exotic ingredient diets.  All this makes it difficult for pet owners to know what is truly the best food for their pet (as opposed to the one with the loudest or most attractive marketing).  Because of the thousands of diet choices, the creative and persuasive advertising, and the vocal opinions on the internet, pet owners aren’t able to know if the diets they’re feeding have nutritional deficiencies or toxicities – or could potentially even cause heart disease.

Apparently, it has become trendy in the pet world (just like the human world) to vilify grains as in this article highlighting potential signs of doggy grain allergy at the dogbaker.com.
Freeman notes that grains are not felt to significantly contribute to pet diseases:

Many pet owners have, unfortunately, also bought into the grain-free myth.  The fact is that food allergies are very uncommon, so there’s no benefit of feeding pet foods containing exotic ingredients.  And while grains have been accused on the internet of causing nearly every disease known to dogs, grains do not contribute to any health problems and are used in pet food as a nutritious source of protein, vitamins, and minerals.

The FDA alert notes that in 4 cases of doggy DCM (3 of which were golden retrievers) taurine levels were low and with a change back to a normal diet and taurine supplementation the cardiomyopathy resolved. However, some reported cases had normal taurine levels.

Reconsider Your Dog’s Diet

To avoid doggy DCM, Dr. Freeman recommends

• Reconsider your dog’s diet. If you’re feeding a boutique, grain-free, or exotic ingredient diets, I would reassess whether you could change to a diet with more typical ingredients made by a company with a long track record of producing good quality diets.  And do yourself a favor –  stop reading the ingredient list!  Although this is the most common way owners select their pets’ food, it is the least reliable way to do so.  And be careful about currently available pet food rating 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 (see our “Questions you should be asking about your pet’s food” post).
• 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).

Anticardiomyopathically Yours,
-ACP