Contrary to popular belief, grain-free diets do not offer
health benefits over diets than contain grains. Dogs are actually considered
omnivores (and thus more similar to bears, skunks and racoons), and both dogs
and cats have the ability to digest, utilize and benefit from a nutritionally
balanced diet containing carbohydrates, including grains. In fact, animals do
not treat grains differently from other sources of carbohydrates like potato
and apple – the body recognizes the food by the nutrients it provides, not by
its source. The starch (the main carbohydrate) in grains is actually highly
digestible for both dogs and cats – 95% or higher.
Many manufacturers, in an attempt to make their diet stand
out in a competitive market, advertise grain-free diets as being healthier, when
in reality they are readily comparable to their grain-containing counterparts.
Many grain-free diets are not actually lower in carbohydrates, but rather use
alternative sources of carbohydrates, such as potatoes and tapioca, which are
actually lower in protein and higher in sugars than grains.
So what other benefits do grain-free diets claim? Some claim
that the risk of food allergies, obesity or diabetes is higher in diets that
contain grains as the source of carbohydrates. True food allergies (reaction of the immune system to certain food proteins) are actually quite rare but can be
caused by any ingredient that has protein. Food intolerances (which don’t involve the immune system) are usually in response to certain nutrient
profiles, such as high-fat diets, and are rarely related to grains
specifically. The most common allergies in dogs are beef, dairy, wheat, chicken
and egg; in cats beef, dairy and fish are most common. Usually animal proteins
are more common causes of allergies than grains or other carbohydrate sources.
However, if an animal is truly allergic to a single type of grain (for example,
wheat), feeding other types of grains (like oats and rice) should not be a
problem.
Obesity is a serious disease that affects a large number of
our animal friends. However, the main cause in both dogs and cats is excessive
calories – regardless of the source. Many grain-free diets are actually higher
in calories and fat; they can be easy to over-feed and the fat makes them very
palatable. Regardless of the type of diet fed, owners should monitor their
pet’s body condition and weight carefully and feed accordingly.
Diabetes in dogs is related to the destruction of specific
cells in the pancreas, and cannot be induced with diet. However, it has been
shown that achieving and maintaining optimal weight and providing a consistent
diet and meal times can help in managing the disease in dogs. Cats, on the
other hand, are prone to developing diabetes if their weight is not-well
managed. As mentioned above, diets containing grains do not promote obesity. While
some research has shown that diets with lower carbohydrate content can be
useful in managing diabetes in cats, most of these diets contain grains.
While grain-free diets can provide excellent nutrition, they
do not offer health benefits over diets than contain grains. It is important to
assess your pet’s diet based on overall nutrient profile rather than individual
ingredients, and to not be swayed by marketing tactics.
Vanessa Tonn, DVM
Bowmanville Veterinary Clinic
