By Matthew Kearns, DVM

I recently had a pet owner come in and ask me if grain-free diets were dangerous. I knew there were risks of bacterial and parasitic contamination in raw diets but had not heard anything about grain-free diets. Time to investigate.  

The origins of the advantages of grain-free diets seem to be driven by the pet food industry itself. There are advantages to using other vegetables (peas, potatoes, chick peas, etc.) as a carbohydrate source if your pet has a documented case of allergies to grains. 

However, the complex carbohydrates and fiber in grains (corn, rice, wheat, barley, etc.) are much better nutritionally and overall digestive health. More recently a new problem has arisen from grain-free diets: HEART DISEASE!!!!

I need to start with a disclaimer that there is no current evidence to link grain-free diets and heart disease but here’s what we know so far: New studies have found that some dogs on grain-free diets are more at risk for a heart condition called dilatory cardiomyopathy (DCM). 

DCM is a heart condition where the heart muscle becomes thin and the heart dilates, or the chambers of the heart expand. Unfortunately, as the heart dilates, the heart becomes an inefficient pump and the patient goes into heart failure. The lung and abdomen then fill with fluid, making it impossible to breathe and, without treatment, is fatal. Even with treatment the patient’s life span is reduced dramatically. Why would grain-free diets cause this? The link seems to be taurine.

A study led by Dr. Joshua Stern (a veterinary cardiologist at the University of California-Davis School of Veterinary Medicine) found a higher number of DCM in golden retrievers. Stern also discovered that many of these patients were on a grain-free diet and had abnormally low taurine levels. 

Taurine is an amino acid, or building block of protein, that is essential for normal heart function. It is found in higher concentrations in muscle of animals including red meats, poultry and seafood. Plants contain very little to no taurine. The lowest concentrations of taurine are found in legumes (peas, chick peas), potatoes and other plants. Some dog foods are supplemented with taurine and some are not.

What to do right now? If your dog is healthy and not showing any symptoms of heart disease (coughing, exercise intolerance, difficulty breathing), you can do a few things: (1) check the taurine content on your particular diet and, if not supplemented, change to a diet that is supplemented, (2) change to a diet supplemented with taurine without checking, or (3) have your dog’s taurine levels tested through your veterinarian’s office and only change the diet or supplement if the levels are low.

Research is ongoing and I will update everyone as soon as I have more information.  

Dr. Kearns practices veterinary medicine from his Port Jefferson office and is pictured with his son Matthew and his dog Jasmine.