Dogs are not small wolves, but it is important to consider their origins when thinking about an ideal diet

Hello friends! Time to answer another popular question: What’s the deal with grain free foods? Why is corn and wheat such a bad idea for pet food? Is it even, or is this over hyped marketing to sell more costly foods that aren’t much better for your pets after all?

To properly answer this question we should start by covering a couple of background concerns. Firstly, to start with deciding what an ideal diet is for our cat and dog family members, we should look at what they would eat if they were left to fend for themselves, as well as looking what their closest wild relatives eat.

Cats are easy; they have not evolved greatly since they domesticated themselves (an interesting story for another time). We were happy to have them live with us and eat our pesky rodents. It wasn’t until very recently that we started feeding cats most or all of their food from processed, human provided sources. Yes, a hungry feral cat will scavenge garbage as well as hunt, but we make garbage easy, and it’s not really healthy. The healthiest feral or free living cats are the ones that are healthy enough and in a good environment to get most of their calories from prey animals. This means cats ideally eat primarily meat, organs, and bones, with a very, very small amount of mostly digested plant material from the guts of their prey.

Short story for cats: Diets high in starchy carbohydrates are difficult for them to process and will often lead to them developing diabetes or other problems (like the heart problems we had in the 70’s covered in this blog on not cooking for your cat). I don’t recommend grain based diets for cats, in the majority of cases it’s really unhealthy for them.

Dogs are a little more challenging because they have been co-evolving with us for a very long time since they diverged from wolves. Initially we welcomed them as companions and helpers on the hunt. You can imagine that a hungry human is not likely to allow their hunting companion to eat the best parts of the meat they captured, so dogs have evolved for a long time to live off of our scraps. This still meant a primarily meat based diet, but even wolves will eat certain fruits if it’s available. When we look at their anatomy, dogs have slightly flatter teeth than cats and a slightly longer digestive tract. This allows them to pull some nutrition out of plant materials, but not a significant amount without our help in pre-processing them.

Because of this the ideal diet for dogs involves a small amount of plant material, but not a lot. Now, because of their more omnivorous leaning digestion, dogs can survive and thrive on a much wider range of diets than cats. This suggests that maybe grains are something they can easily process and thrive on.

Hold on just one minute!

Let’s look at why grains are even put into cat and dog foods. Back in the post-WWII era, dry food was surging in popularity, modern extruders had just been invented, and companies were in a race to see who could produce kibbles with the best consistency and the most cost efficiency. It turns out grains were an excellent way to do both of these things. Corn and wheat being very cheap and plentiful, they were often the ingredients chosen. For cats this became a big problem, but dogs were largely unaffected because they could handle converting the amino acids available into all the proteins they needed.

Fast forward to today (really not all that far forward), and these companies are, of course, still looking for the cheapest sources of ingredients. Corn and wheat remain the most plentiful and cheapest, and they are also our most commonly genetically modified crops (along with soy). This means that, unless you’re buying organic pet food, the corn and wheat in your dog’s food is almost guaranteed genetically modified, which also means that it probably has high concentrations of pesticides.

Additionally, grains are not the most bioavailable source of protein (yes, the corn and wheat gluten is used to boost the protein content), which makes these foods not as easily digested as foods with more animal sourced proteins.

But someone with an education told you they learned that grains are perfectly good protein sources? Yeah, I learned that in vet school too, in a month long nutrition course taught by a representative of the Mark Morris Institute (MMI). That might sound authoritative, but the MMI is actually the non-profit side of Hill’s/Science Diet, so it isn’t exactly without conflicting interests. I also learned that when I took the Hill’s Pet Nutritional Advocate certificate training and, again, I have good reason to suspect that the education there was not free from bias. The education in cat and dog nutrition that the vast majority of veterinarians receive in our standard vet school training is very basic, and every veterinarian I’ve met who has an interest in nutrition has always done further study either on their own or through additional courses to gain a depth of knowledge not available in the MMI sponsored basic course.

The take away? Grains are not a good idea for cats really at all. Grains and dogs get along ok, but they are not good sources of protein. So while I’m ok with barley, rice, or oats in dog food (lower protein grains), I do not like to see corn or wheat, particularly if the ingredient is actually corn or wheat gluten. That tells me they are using that as a cheap protein source to avoid adding more of the more expensive animal products.

Yes, finding a good food for your pet is tricky. Reading the labels is a must and finding a good holistic veterinarian to advise you is always helpful.

Have questions? Email me! I love blogging, especially when I know it’s answering my tribe’s questions.

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