You may have heard recently that grain-free dog foods are falling out of favor.
The reason is that they have been implicated in a recent surge in a dilated cardio-myopathy (DCM) in dog breeds that had previously rarely affected by the disease.
DCM is a defect in the heart muscle that causes it to become weak and flabby. As a consequence, the walls of the heart chambers, which pump blood to the lungs and the rest of the body by squeezing the blood through, get stretched out, with thin and inefficient muscles.
As the disease progresses, it can cause chronic congestive heart failure (CHF), with fluid building up in the lungs impeding the uptake of oxygen into the blood. Early signs of this are exercise intolerance, increased respiratory rate, and panting. Later signs are coughing, bluish tongue and gums, and eventually death. The alternate course of DCM is to develop heart arrhythmias, which can go undetected until they cause fainting or sudden death.
The relationship between grain-free diets and DCM was recognized by Dr. Josh Stern, a veterinary cardiologists at the UCD School of Veterinary Medicine Teaching Hospital (VMTH). He initiated a study of the newly emergent problem and has expanded it to include the veterinary nutritionists at UCD, and veterinary cardiologists practicing at several different universities in the US.
At this time, our understanding of the link between grain-free dog food diets and DCM is incomplete. So far it is believed that:
Grain free diets that are high in potatoes or legumes (beans, peas, peanuts) have been fed for a year or more in the identified cases;
These diets may be lacking in the amino acid taurine that is essential for healthy cardiac muscle development;
Cessation of the grain free diet and supplementation with taurine is effective in reversing the muscle disease, when done soon enough.
For this reason, veterinarians and the FDA are recommending NOT feeding an exclusively grain free diet to your dogs.
If you are concerned that your own dog may be suffering from the effects of prolonged feeding of a grain-free diet, please consult with your veterinarian. Taurine supplementation should not be attempted without the guidance of a veterinary nutritionist or veterinarian.
For more information on the topic: