Inevitably during a traditionally hectic day of patient consultations, at least one pet parent tells me s/he feeds her/his pet a grain-free diet. Yet when I ask why such a diet was selected, I’m rarely met with a response based on sound scientific evidence. Rather the reply is usually something like “I read online that grains are bad for pets.” Thus to provide some informed data, this week I spend time discussing the purported pros and cons of grain-free diets for dogs and cats. Happy reading!
Grains – what are they?
Grains are simply seeds from specific grasses. They contain large amounts of carbohydrates, as well as lesser amounts of proteins, fiber, vitamins, and minerals.
Common examples are grains are:
- Rice (black, brown, white, forbidden, wild)
Grains – why are they used in pet foods?
There are several nutritional reasons grains are incorporated into pet foods. As mentioned earlier, they are healthy sources of multiple key nutrients, including carbohydrates, proteins, vitamins, and minerals. Certain grains are also wonderful sources of fiber. Grains also provide a relatively inexpensive substrate for binding kibble and providing overall bulk.
Grains – why are they so maligned?
Two of the most common arguments for feeding grain-free diets are:
- Eating grains isn’t natural
- Processed grains are not healthy
The wild ancestors of our companion animals didn’t eat a lot grains. Wolves and wild felids hunted and captured raw, protein-rich meals. Indeed, their primary exposure to grains was the contents of the innards of their prey. Thus a protein-based, grain-free food more closely resembles a dog’s or cat’s ancestral diet. Does this matter? For example, one canine study showed the genetics of dogs have evolved through domestication. Thus the dietary requirements for our domesticated dogs are not the same as those of their ancestors. Should we expect domestic canines with an evolved genome to eat the same foods as their wild relatives?
Most know eating whole grains is considered healthier than ingesting processed ones. Through the refining process, grains lose their germ and bran, thus stripping them of the majority of their nutritional value. Pet foods containing large quantities of highly-refined grains are considered less nutritionally sound than those with whole grains.
Grains – should you avoid them for your pets?
Many factors are involved in selecting the most appropriate diet for a pet, including:
- Pet’s preference
- Availability of the desired food
- Pet’s medical history
In my experience, most dog parents switch to grain-free diets because they believe their fur babies have allergies. They see their canine companions licking excessively, sneezing, and/or scratching. Their pets have recurrent ear and/or skin infections. Given pet food companies have been remarkably successful convincing many pet parents that grains are pure evil, the families switch their dog’s diet to one free of grains. I understand this choice is made with the singular intention of making a pet feel better, but the logic is simply not necessarily sound. Thankfully feeding grain-free diets are unlikely to be harmful to dogs. Yet to date, there is no solid evidence they are actually helpful!
Cats, as usual, are a slightly different story. These curious critters are obligate carnivores, meaning eating meat is a biological necessity. Cats, including domesticated ones, are simply not built to digest large amounts of carbohydrates and plant-derived proteins. Thus feeding cats grain-free diets is logically quiet sound. Yet many thrive eating diets with quality grains, so is feeding a grain-free diet an absolute necessity? The jury is still out!
The take-away message about grains and grain-free diets…
I recommend pet parents avoid consulting with individuals and/or resources with no credentials in animal nutrition, yet alone veterinary medicine. The worker at PetSmart or your local boutique pet bakery really isn’t a reliable source of evidence-based nutrition recommendations! Your best source of information about pet nutrition is your family veterinarian. You will also find it beneficial to partner with a board-certified veterinary nutrition specialist or board-certified veterinary internal medicine specialist.
To find a board-certified veterinary nutrition specialist, please visit the American College of Veterinary Nutrition.
To find a board-certified veterinary internal medicine specialist, please visit the American College of Veterinary Internal Medicine.
Wishing you wet-nosed kisses,