FOOD FOR THOUGHT #2

When the FDA announced their investigation of a possible link between diet and a particular kind of heart disease being seen in dog breeds without a genetic predisposition, "FDA Investigating Potential Connection Between Diet and Cases of Canine Heart Disease," it set the pet food industry and consumers (and veterinarians) all abuzz. The buzz and the investigation continue with the February 2019 FDA update (FDA Provides Update on Investigation into Potential Connection Between Certain Diets and Cases of Canine Heart Disease) informing us on the directions of the inquiry while making it clear they are far from reaching any conclusions. One thing that is clear is that this will be another example of how little we know about everything which may make it easy for some to panic and hard for others, like me, to calm those concerns.

I can summarize what is known and what has been seen. The specific kind of heart disease is DCM, Dilative Cardiomyopathy, which describes a heart muscle that loses contractile strength which leads to failure of the heart’s ability to pump blood. There are a number of breeds that have a genetic predisposition to this type of heart disease. In the last few years, veterinary cardiologists across the country have been seeing DCM in these at-risk breeds as well as other breeds along with a correlation with what they are eating, namely grain-free (and fewer non-grain-free) diets often high in legumes and pulses (peas, lentils, chickpeas) or potatoes (includes sweet potatoes) and to a lesser extent, diets with unusual protein sources. In some of these cases a blood taurine deficiency has been found (taurine is an amino acid that dogs can make on their own from dietary sulfur-containing amino acids methionine and cysteine) and in some of these cases a diet change has resolved the problem. But clearly not all of the cases involve grain-free diets or taurine-deficient patients and the diets themselves are not overtly deficient in taurine or, more importantly, taurine precursors. That would be too simple. As I said, we know so little, though it would seem plausible that there could be multiple causes of diet-related DCM and not one single answer (like the question “What causes cancer?” not having a single answer).

Are owners supposed to do something with this preliminary information? Maybe. First, don’t panic. The case reports the FDA and cardiologists have accumulated over a few years number in the low hundreds as compared with the tens of millions of dogs in this country, many of which have been eating grain-free diets without a problem. As a reality check, obesity destroys the quality of life and shortens way more dog lives than this problem ever will so worry about calories before you worry about DCM. Feeding a diet high in legumes and/or potatoes? Maybe rotate diets and don’t feed just one food for months or years on end (see Food For Thought #1). Be educated and check out the links below for more info. And if you really want to see your veterinarian sweat, ask her or him something like, “What should I feed my dog?” More on that in Food For Thought #3.

Read an excellent overview of the situation in this news article from the Veterinary Information Network: "Unconventional dog foods suspected in heart disease," or their February 19, 2019 update, “Diet-related heart problem reported in 325 dogs.”

To get a veterinary nutritionist’s point of view, Dr. Freeman, a specialist at Tufts’ veterinary school, puts her spin on the issue in one of her Petfoodology blogs: "It’s Not Just Grain-Free: An Update on Diet-Associated Dilated Cardiomyopathy."

If you’ve really got time on your hands, check out Dr. Freeman’s original blog on the subject, “A broken heart: Risk of heart disease in boutique or grain-free diets and exotic ingredients” in which she will really challenge your pet food beliefs (like telling you to stop reading food ingredient labels and start picking foods by manufacturers that use actual food trials to test their diets).

Like I said, we know so little!