Table of Contents:
- Why Are Grains Used in Pet Food?
- Aren’t Grains just “Filler”?
- Can Dogs and Cats Digest Grains and Other Carbohydrates?
- Are Grain-Free Diets Healthier than Grain-Inclusive Diets?
- Do Grains in Pet Food Cause Allergies?
- Are Grain-Free Pet Foods Safe?
Why Are Grains Used in Pet Food?
Grains are any cultivated cereal crop, including common ingredients in pet food like rice, corn, wheat, and barley. Cereal grains can provide energy and various nutrients including dietary fiber, essential fatty acids, essential amino acids, vitamins, and minerals. Dogs and cats can digest and absorb many of the nutrients found in grains. The amino acids provided by grains can be complementary to the amino acids provided by animal-based proteins, which can reduce food costs and improve sustainability. While dogs and cats do not have a nutritional requirement for fiber, the dietary fiber found in whole grains can promote gastrointestinal health.
Aren’t Grains just “Filler”?
Sixty-three percent of pet owners described a grain-free diet as a diet free of “fillers.” Using the term “filler” to describe grain in pet foods is a common misconception. This implies that grains provide no nutritional value, which is not the case. Grain-free pet foods generally include legumes and/or starches like potato and tapioca as their carbohydrate sources. Refined starches contain fewer nutrients when compared to whole grains. Pet owners may select grain-free diets as they perceive this to be more natural, however, potatoes and legumes are also not part of the natural diet of wolves and wild cats.
Can Dogs and Cats Digest Grains and Other Carbohydrates?
Originating from a scavenging lifestyle, domesticated dogs are adapted to thrive on a starch-rich diet. Dogs demonstrate changes in expression and activity of various genes that favor starch digestion when compared to wolves. The concept of feeding a dog like a wolf is dated. While cats generally consume less carbohydrates than dogs, they can utilize the energy and nutrients found in grains. Starch digestibility was high (over 93%) in cats fed diets containing various grains and non-grains.
Are Grain-Free Diets Healthier than Grain-Inclusive Diets?
Currently, there is no evidence that feeding a grain-free diet provides superior nutrition for cats or dogs. The marketing of grain-free diets suggests that the quality of this pet food provides a superior form of nutrition. Many pet owners believe that feeding these types of diets will generate various health benefits, including reduction in food allergic disease and better gastrointestinal (GI) health. While grain-free diets can provide complete and balanced nutrition, they are not nutritionally superior to diets that contain grains and remain primarily a marketing concept to appeal to pet owners.
Do Grains in Pet Food Cause Allergies?
Many pet owners believe that feeding a grain-free pet food can lessen the occurrence of skin or gastrointestinal food allergies. The prevalence of skin-related adverse food reactions for dogs and cats is reported as up to 24% and 6%, respectively. The most common reported food allergens contributing to canine skin-related adverse food reactions are beef (34%), dairy products (17%), chicken (15%), and wheat (13%). Less common food allergens reported in dogs (≤ 6%) include lamb, soy, corn, egg, pork, fish, and rice. In cats, beef (18%), fish (17%), and chicken (5%) were the most common food allergens. Wheat, corn, dairy products, and lamb were also reported (≤ 4%). While it is possible for dogs and cats to have an adverse food reaction to a grain, there is no evidence to suggest that exclusion of grains from the diet will lessen the likelihood of food allergic disease.
Are Grain-Free Pet Foods Safe?
Unfortunately, this is a complicated question without a clear answer. In June of 2019, the Food & Drug Administration (FDA) released their most recent update on the investigation of canine heart disease (i.e. dilated cardiomyopathy) and its potential association with various diets, including those of the grain-free variety. Currently, a cause-and-effect relationship between heart disease and grain-free diets has not been proven. Grain-free diets are diverse in their ingredients, nutrient profiles, digestibility, and bioavailability of nutrients. To say that “all” grain-free diets are unsafe is inaccurate, but that doesn’t change many pet owner and veterinarian apprehensions. The FDA is currently not advising dietary changes based on the information they have gathered so far. Pet owners concerned about their dog’s diet are encouraged to discuss this with their veterinarian. The World Small Animal Veterinary Association (WSAVA) has released a list of questions/guidelines to help consumers select commercial pet food.