Grain-free diets…do they really cause heart problems in dogs?

Grain-free diets…do they really cause heart problems in dogs?

While the recent headlines may sound alarming, the connection between grain-free dog foods and heart disease isn’t as clear-cut as many believe.

You’ve probably seen the headlines: “Grain-free diets linked to heart disease in dogs!” These claims arise from speculations that foods which negatively affect taurine status are leading to taurine-deficiency dilated cardiomyopathy (DCM) in dogs. Foods that contain high levels of peas, lentils, and potatoes are identified by the FDA as potential risk factors, and these common ingredients are found in many “grain-free” pet foods. But are grain-free diets really causing heart disease in our dogs?

Research suggests that diet is a factor in only about 30% of dogs with DCM. Some dogs with DCM – but not all — will improve with taurine supplementation. This demonstrates that multiple influences are involved with the DCM disease process, and that the exact role and impact of dietary taurine appears complex and is not yet fully understood.

What is taurine?

Taurine is an amino acid found primarily in meat. It is required for the proper function of muscle tissues — especially the heart. It is not normally a requirement in canine diets, since dogs are generally able to synthesize it from other amino acids found in proteins within meat, poultry, fish, and eggs.

Taurine is found naturally in animal-based proteins (meat, fish and eggs) but not in plant-based protein sources. As well, the high temperatures and extreme heat still used to process many pet foods alter the bioavailability of taurine. Diets that include high quality animal proteins, and that aren’t heat-damaged, should provide adequate taurine. Conversely, low quality proteins or excessively heat-treated foods will be poorly-digested, thereby reducing taurine availability.

In short, the issues implicating “grain-free” pet foods as a potential health risk may be associated with the following factors:

  1. Most low quality grain-free foods have high concentrations of plant-based proteins, such as lentils, peas and other legumes, as well as potatoes.
  2. Most of these pet foods are heavily processed and heated at extremely high temperatures, which alters the bioavailability of taurine.

Your dog’s gut microbiome

Another factor that plays a major role in taurine deficiency involves the dog’s gut microbiome. It appears that bacterial microbes in the gut have a significant impact on the processing and utilization of taurine. When the microbiome is shifted out of balance, it can create an environment in the gut that favors bacteria that degrade taurine, making this amino acid less available to the dog’s body, including his heart.

A recent report explains that the link between grain-free foods and heart disease is likely a multifactorial problem related to alterations in gut flora, perhaps arising from high percentages of legumes in lower quality “grain-free” diets, that can change taurine absorption and alter its digestibility and bioavailability.

As you can see, saying that “grain-free foods cause heart disease” is too simplistic. Many factors are involved, so feeding your dog a grain-free diet doesn’t mean he’s definitely going to develop heart disease!

Making food choices for your dog

  1. Buy a good quality food that contains plenty of animal-based protein like meat, poultry, and fish as the top ingredients.
  2. Avoid foods that rely on legumes or potatoes as their primary ingredients.
  3. Look for foods that are minimally processed to preserve naturally-occurring nutrients such as taurine.
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Dr. Katie Kangas graduated from the University of Wisconsin Veterinary College in 1993. She achieved her CVA certification at the Chi Institute in 2008, followed by additional training in Advanced Acupuncture, Food Therapy, Herbal Medicine and Veterinary Orthopedic Manipulation. Dr. Kangas owns Integrative Veterinary Care in San Diego, California. Her areas of special interest include nutrition/food medicine, dental health and pain management.