Mary Allen
Many unsure customers ask us whether they should feed their dogs grain-free. You hear and read again and again that grain in dog food is not species-appropriate and harmful. However, veterinary findings do not confirm this.
What is a Grain Made of?
Cereals such as wheat or rice mainly contain carbohydrates, mainly in the form of starch. Many dog foods marketed as “grain-free” do not contain grains but do contain potatoes and various other vegetables, fruits, or nuts. Its main component is: also starch because all plants store energy in the form of starch.
Regardless of the source, the digestion of starch in the dog’s intestine is always the same (see below).
Does Grain Cause Allergies?
It is often said that cereals trigger allergies in dogs. The terms “allergy” and “gluten intolerance” are sometimes mixed up. In the case of gluten intolerance, which we know from human nutrition as “celiac disease”, the intestine reacts with an inflammatory reaction to the so-called wheat gluten protein, i.e. gluten. The inflammation resembles an allergy in some respects and more like an autoimmune disease in others. Hereditary gluten intolerance in Irish Setter families has been described in the specialist literature but is now considered to be eradicated. Otherwise, according to the current state of research, gluten intolerance in dogs is irrelevant.
An allergy to grain protein is also possible in dogs. However, grain protein is not per se more allergenic than other proteins, and genuine feed allergies are less common than is commonly assumed. Since allergies are usually directed against proteins, dogs are usually allergic to protein-rich and commonly used feed components such as various types of meat, eggs, or cow’s milk. For example, a 2009 scientific study ranked gluten far behind beef as the cause of allergic reactions. No one would therefore think of generally advising against feeding meat.
Do Dogs Tolerate Carbohydrates?
As mentioned, the main component of cereals is carbohydrate starch. It is digested by the pancreas releasing the enzyme amylase. It breaks down starch into sugar molecules, which are absorbed into the bloodstream to provide energy. Accordingly, grain is not just a “cheap filler” that would be worthless for the dog, but a good source of energy.
Interestingly, unlike cats, dogs can ramp up amylase production when fed a high-starch diet. So they can adapt to a starchy diet so well that up to two-thirds of the energy in the feed can come from carbohydrates. If dogs did not naturally eat carbohydrates, this adaptation mechanism would be pointless.
If a dog food contains more than 60% carbohydrates, dogs who eat it will get diarrhea because undigested starch has an osmotic effect and draws water. As a pet owner, you notice this immediately and would no longer feed such food. A manufacturer can therefore have no interest in mixing more starch into dog food than a dog can tolerate.
Are Grains in Dog Food Unnatural?
Dogs are considered “meat-eaters” (carnivores), which is often taken as an argument to feed them exclusively or almost exclusively with meat. But taken literally, the term carnivore is misleading.
Feeding dogs only meat is not species-appropriate and leads to malnutrition because, like wolves, dogs need the nutrients that the bones, blood, and gastrointestinal contents of their prey provide them with. Especially the intestinal contents as a source of food for wolves are often forgotten. However, dogs and wolves are dependent on the carbohydrates that are naturally provided by the intestinal contents of their prey: the soluble carbohydrates – such as starch – and the insoluble carbohydrates (fiber) – such as cellulose from plant fibers, which is also notorious as a cheap bulking agent. Although insoluble carbohydrates do not provide the dog with any energy, they are important for intestinal flora and intestinal motility. That’s why dogs like wolves like to eat grass, berries, or roots. They would not spurn the carbohydrate-rich stomach contents of a wild boar, which devoured large quantities of grain and nuts.
More recent findings published in the renowned journal “Nature” at the beginning of 2013 also show a clear difference between the nutritional needs of dogs and wolves: in the course of domestication, dogs have managed to adapt to human nutrition. With the advent of agriculture (about 10,000 years ago), both humans and our dogs developed the ability to digest larger amounts of starch and use it as a source of energy.