The Question of Grains
One of the biggest movements in pet food the last few years has been a shift towards grain free products. Treats, food, and even some chewable medicines now advertise themselves as grain free. And all of it comes from a great place-wanting the best and healthiest lives for our pets. Despite it's rising popularity, though, it's uncertain whether or not grain free diets are actually better for our pets.
On the one hand, it's easy to see how grain free diets would be healthier. I mean, dogs are carnivores evolved from wolves and in the wild they persist on almost entirely meat-based diets. But after 10,000 years of domestication, have the stomachs of dogs adapted to better digest grains and carbs? Canine geneticist Robert Wayne argues that yes, they have, and that as much as half of a modern dog's diet can be carb-based. Dr. Becker, on the other hand, argues that a dog's short digestive tract is still more heavily bent towards digesting protein and fat over grains and sugars.
One of the things both parties agree on, though, is that consumers can mistake 'grain-free' packaging as "carb-free" or "healthier" without giving much second-thought to reading the ingredients list. As someone who was on the keto diet for over a year, I can tell you from experience that something marked 'grain-free' or 'gluten-free' is, surprisingly, almost always higher in carbs. This is as true for dog food as it is for people food. Many veterinarians report no change in weight between grain-free and not grain-free pets, and it is very possible that this is due to the presence of the replacement fillers in grain-free dry food. Starches from potatoes, peas, and lentils are more carb dense and also tend to have a higher fat-content than their grain counterparts, so watch the labeling on pet foods even when they advertise 'grain-free'.
Besides the lack of weight loss and genetics arguments for each side, one of the strongest arguments against grain-free diets is the simple fact that dogs rarely develop allergies to grain. They are far more likely to develop an allergy to some form of protein such as chicken or beef than to develop an allergy to the filler between it in dry dog food.
It's perfectly possible to provide your dog a balanced diet with all the nutrition they need either way, just make sure to consult a veterinarian before any major changes.