DCM #2 – Purina vs. Blue Buffalo: The Big Grain Debate

I wrote this as a three part blog series.

In part one, I share my personal experiences that led me to recommended Grain Free diets for my patients in the first place.

In part two, I will look at the differences between the companies that make the Grain Free brands vs the traditional Grain Inclusive brands.

In part three, we look at why grains could be a problem for dogs.

In the next series, I tackle the discussion of the cardiomyopathy more specifically. (Coming soon!)

I have also put together a PDF available for download that includes my recommendations on dog foods, supplements and what to feed your pets in light of these recent DCM controversies. (Coming soon!)

Grain Free vs Grain Inclusive

In the pet food world today, there seems to be a somewhat arbitrary divide between types of dog food: Grain Free (no grains) and Grain Inclusive (has grains).

On the surface, this divide leads us to ask the question: should dogs eat grains or not?

But the underlying discussion actually doesn’t have that much to do with grains. Rather, it is more about the corporate players on either side of this debate and the particular ingredients that they are putting in pet food (some of which happen to be some grains.)

The real question is rather: should you feed the brands of dog food made by Grain-Inclusive companies or by the Grain-Free companies? (I use capital letters here because these distinctions have almost become their own entities at this point).

In order to better understand this debate, it helps to have a little background.

Five Categories of Dog Food

Let’s begin by looking at the FIVE basic categories of dog food. There is a degree of overlap between the categories because some companies make pet food that belongs in a few categories, but for the most part, each brands identifies primarily with one group.

1) Supermarket Dog Food

This is the quintessential dog food that has dominated the pet food market for the past 100 years or so. It’s what you can buy at a supermarket, or a big box retailer like Walmart or Target. It is generally the lowest quality of dog food you can find on the market with toxic preservatives and many other disconcerting ingredients. 

These brands are mostly Grain Inclusive.

Examples of brands in this category include: Pedigree, Beneful, Old Roy, Alpo etc.

2) Veterinary Recommended Brands

These brands of dog food have a unique and strong relationship with the veterinary community. Many have criticized this relationship and worry about the conflict of interest. On the plus side, these companies do perform a lot of animal nutritional research. On the downside, they have historically used many of the same ingredients as those found in supermarket dog foods, but with less of the toxic preservatives. 

These brands are mostly Grain Inclusive.

There are only four companies in this category: Hills Science Diet, Purina, Iams/Eukaneuba and Royal Canin.

We will look more closely at this category in a minute.

3) Grain Free Diets

These diets were initially created largely by pet owners, grassroots efforts and mom-and-pop type companies that were worried about the ingredients found in supermarket and veterinary recommended dog food. While some of these companies came to the market in the late 90s, most of them arrived on the scene in the early to mid 2000s.

Grain Free diets tend to not include animal-by-products and also avoid ingredients such as wheat, corn, rice and soy. This is why they are labeled as being Grain Free.

We will also look at these diets more closely in the next section.

These brands are Grain Free.

Examples of Grain Free diets: Blue Buffalo, Orijin, Instinct, Taste of the Wild, etc.

4) Raw Diets

Raw diets were first introduced in a book written by the veterinarian Dr. Ian Billingworst’s, called: Give Your Dog A Bone. They are generally composed of raw meat, bones, organ meats +/- some fruits and vegetables. Today, they come in a variety of forms: fresh, freeze dried, frozen, air dried and *raw meat coated kibble.

A large majority of my clients feed their pets raw diets. The fears about bacterial contamination, while justified, have been more theoretical in my experience. Surprisingly, very few dogs get sick when eating raw food. I believe that for some dogs raw diets can be very beneficial for their health, and for others, they are likely not necessary. I will write a separate blog post on this topic in the future. 

These brands are mostly Grain Free.

Commercial brands of raw food include: Primal, Stella and Chewies, and Nature’s Variety.

*Raw Coated Kibble This is not actually raw food, but kibble. I am not sure how the companies add the “raw coating,” but this is more of a marketing claim than true raw feeding. I have seen this create some confusion in the recent DCM complaints to the FDA. In the reports, some pet owners wrote that they were feeding “raw food,” when in fact, they were feeding “raw coated kibble,” which is not actually raw food. There were 3 cases of dogs actually eating more traditional raw and dehydrated raw food and each of those cases was a little unique. This is just something to know when reading reports of “raw fed” dogs developing DCM.

5) Home made dog food

These are diets made at home using “people food,” or real food. It can be raw or cooked. Some are made using a recipe or with the help of a nutritionist.

You can now purchase home cooked dog food with some companies such as: Just Food For Dogs.

We will save the topic of home made diets for another post.

These diets are either Grain Free or Grain Inclusive, based on the owner’s preference.

Grain Free Diets vs Grain Inclusive Diets: A Little Background

We will now spend the rest of this post looking specifically at Grain Free diets vs. Grain Inclusive diets, and the corporations behind each of these types of feeding. With the recent cardiomyopathy (DCM) cases, there are many discussions about which type of food is better for dogs.

In order to better understand both sides of this debate, it’s good to have some background and put everything into some context.

So let’s have a quick look at where both of these diets came from.

Bowl of dog food

Dog food was created in the late 1800s by an electrician and lightening rod salesman named James Spratt. He used the technology of that time to create biscuits that could be marketed to pet owners: at the time, this group mainly consisted of the owner’s of sporting and hunting dogs.

In the early 1900s, a lot of dog food was made using horse meat. Not because it was particularly nutritious for dogs, but because a lot of horses died during the early automobile age and also during World War I. Something had to be done with all the cadavers, and so for the most part, it became dog food.

Picture of a vintage can of Ken L ration dog food
Check out the ingredient list!

It is no coincidence that most early dog food companies were built next to food manufacturing plants for people. Whatever waste was leftover from the manufacturing process for food for people, went into dog food.1

For most of the 1900s, veterinarians were a bit wary of commercial dog food. But by the 1960s, the convenience of dog food and heavy marketing paid off, and in most of the developed world, commercial dog food became a normal part of every day life. By the 1960s, there were thousands of dog food brands on the market.2

For most of its history (some would argue, even today), there has been minimal regulation of dog food. AAFCO (The Association of American Feed Control Officials) didn’t become involved until the late 1960s. Most of their influence was focused on proper labeling and the creation of the Complete and Balanced label standards. Even today AAFCO has no regulatory power.

There are also no rules or regulations for the actual ingredients that go into dog food.

And so, while dog food has often been labeled as being scientifically formulated with hand picked ingredients chosen specifically for our canine companions, the truth is that for most of its history, dog food has basically just been: human food leftovers.

In the 1920s, those leftovers consisted largely of horsemeat. Today, those leftovers are mainly chicken-by-product, corn and soy.

In other words, the main ingredients left over from processed food for people.

1-2 Grier, Katherine C. Pets in America, Chapel Hill: The University of North Carolina Press, 2006.

Animal by-products

One particularly controversial ingredient began to make its appearance in dog food starting around the 1960s: Animal by-products.

The official definition of by-products are the “parts”, other than meat, derived from slaughtered mammals. It includes, but is not limited to lungs, spleen, kidneys, brain, blood, bone, fatty tissue and stomachs and intestines freed of their contents. According to the AAFCO website, by-products: include meat that doesn’t meet aesthetic standards, or internal organs or other parts that normally aren’t used for human food.

This is the good part of by-products. Organ meats are highly dense sources of nutrition for dogs and cats.

However, there are many concerns over how these by-products are produced and what actually makes its way into this category.

In rendering facilities, where animal by-products are made into a usable substance sold to pet food companies, the animal parts are combined into one large vat, or tank, and cooked at high temperatures to produce the final product. While there are general categories of by-product types, there is not much regulation or oversight when it comes to what actually finds its way into these vats.

Whistle-blowers, such as Susan Thrixton, have described the common practice of including meats that come from the four Ds into pet food: Dead, Dying, Diseased and Disabled animals. This includes everything not fit for human consumption: cows with cancer and large tumors, animals that were found dead in their pen, and sections of meat that were repeatedly injected with antibiotics.

There are even some concerns about euthanized cats and dogs being added into the rendering vats.

An account of a retired pest control officer that helped with a rat problem at a rendering facility describes what he saw in the rendering vats:

As you might imagine, this area was loaded with flies; the piles of products were alive with maggots. It made it look like the whole pile of product was alive and moving. After the loads were dumped they were picked up by a bobcat (a miniature loader with a scoop on the front) and hauled inside the plant to the rendering pit.There was a small seem 1 inch wide about 4 feet down that ran all the way around the pit. This seem, as the ones in the corners, had several rat holes in them, so rats were living in the rendering pit.

I asked where the finish products were sent to; they said it was shipped to several different pet food plants... 

 Not only were dead animals that died who knows how being rendered, but also live rats, a lot of rat droppings plus all the dirt and concrete fragments that were removed from the rat holes in the pit and piles of maggots. But ‘that was ok’ because it was just going for pet food.

Accounts such as this, for good reason, have made pet owners nervous.

Many pet food companies claim that these reports are not true.

However, the fact that pentobarbital, the drug used to euthanize cats, dogs and horses, has been found in pet food over the years, has raised some questions. Pentobarbital is not used in factory animals such as cows and chickens. If pet food were truly made with only clean organ meats from cows and chickens, there would be no way that pentobarbital would be found in pet food.

This is why many pet owners continue to be wary of animal by-products, a common ingredient in many Grain Inclusive diets.

Grain Inclusive Dog Food: The Big Four

Somewhere around the 1980s/1990s, certain pet food companies began to form stronger relationships with veterinarians. Hills Science Diet was actually created by a veterinarian who made a low protein diet for dogs with kidney disease.

Through a series of events in the late 90s, these companies began to employ veterinarians at their companies and work with them more closely.

This formed, what on the surface was a win-win relationship:

Veterinarians were involved in the process of dog food and could make sure that the diets were scientifically formulated. At the same time, these four pet food companies got the seal of approval from veterinarians, which helped market and increase their sales.

While Supermarket Dog foods, like Alpo and Pedigree, are technically also Grain Inclusive, when most people recommend Grain Inclusive dog foods, what they are really talking about are dog foods made by the Veterinary Recommended brands, which are these four:

Hills Science Diet


Royal Canin


However, despite the strong relationship with the veterinary community, and the emphasis on science and research, the companies continue to use the same ingredients as “supermarket” brands in their pet food.

Animal by-products and leftovers from processed food: corn, soy and wheat, formed and continue to form the majority of ingredients found in the Veterinary Recommended brands.

The companies did take out some harmful preservatives such as BHT.

It was these concerns that led to the creation of Grain Free diets…

Grain Free Diets

As I mentioned in the previous description, the Grain Free diets were initially created largely by pet owners, grassroots efforts and mom-and-pop type companies that were worried about the ingredients found in supermarket and veterinary recommended dog food.

The grain free movement was likely spearheaded by the veterinarian Ian Billingwurst and his book Give your dog a bone in 1996, which first introduced the idea of feeding raw meat and bones to dogs and taking out processed food and grains. While this idea was gaining followers in smaller niche circles of pet owners (particularly in Australia where Dr. Billinghurst lives), it was likely the paleo diet for people that took the grain free movement in pet food to a whole new level.

The Paleo diet, a diet popularized by a book written on this topic in 2002, is a diet that consists of meat, nuts, root vegetables, berries, or basically anything that our hunter-gatherer ancestors ate. While there are variations of this diet, the most distinctive feature is that it omits all grains on the premise that they weren’t a part of our human diet until after the agricultural revolution about 10,000 years ago.

As people began to think more about eating an ancestral diet for themselves, they also began to think about it for their pets. Dogs originated from wolves. Dogs are are so closely genetically related to wolves, in fact, that dogs can mate with wolves and have viable offspring. Wolves eat primarily carnivorous diets. Pet owners were concerned that dogs were being fed dog food with high concentrations of corn, soy and wheat, while their nearest ancestor ate none of these things.

I’ll save this discussion for later blog posts, but this at least gives you an idea of the conversations that were happening around this topic.

Grain free diets, whether knowingly or unknowingly, were also taking advantage of a bit of word association with the paleo diet, implying that by avoiding grains, the grain free diets were also high in meat protein. Brand names such as: Orijin, Instinct and Taste of the Wild were chosen to also give the idea of ancestral, carnivorous diets.

And while some of the grain free diets were and ARE high in animal protein and follow a paleo ancestral diet concept, there are many of the grain free brands that are actually still high in carbohydrates and starches.

In some cases, the Grain Free diets have more carbohydrates than their Grain Inclusive counterparts! But instead of using the typical grain ingredients found in supermarket and veterinary recommended brands (corn, soy, wheat, rice, etc), they substituted these ingredients for sweet potatoes, potatoes, lentils and peas.

In recent years, it seems that some of these combinations may be causing problems for some dogs, most notably, possibly be causing DCM, or dilated cardiomyopathy, which we will look at in the next articles of this blog series.

Nutritional Research: Grain Inclusive Pet Food

One of the common arguments for why you should feed Veterinary Recommended brands (Grain Inclusive) over Grain Free diets, is that the Grain Inclusive companies employ many veterinarians and perform nutritional research.

And this is certainly true.

Their research has likely saved and improved the lives of many animals.

The veterinary prescription formulas for cats prone to urinary blockages has likely saved thousands (perhaps even millions?) of cats’ lives and decreased the amount of stressful veterinary visits for these patients.

Their prescription formulas for dogs with bad skin allergies has also helped many dogs live more comfortable lives. Although, to be fair, in my experience many dog’s skin allergies improved when switched to a Grain Free brand as well. But this does not take away from the fact that many dogs have also been helped with the hypoallergenic veterinary prescription dog foods.

There are also many, many, many good people working for these companies who truly believe that they are doing the best thing for animals. They love animals and have only the purest and best intentions at heart.

The vast majority of veterinarians recommend feeding Grain Inclusive pet food, and specifically, the BIG FOUR brands because they believe in the science and the research that the companies are conducting. They also feed these diets to their own pets!

And while it is true that veterinarians are taught to recommend these brands of food during veterinary school, one could argue, that this is BECAUSE of the research and solid track record of these companies.

However, what concerns me is this…

Troublesome Ingredients

In the previous blog post, I talked about how I felt that I saw a disproportionate amount of pets develop diabetes that ate the Grain Inclusive diets.

When I would ask owners of the newly diagnosed diabetic pets what they were feeding, one brand in particular seemed to show up a lot: Purina’s Beneful.

And so, I decided to take a look at the ingredients.

And what I found, shocked me:

DCM BLOG SERIES: #2 - The Big Grain Debate

Sugar has a concerning connection to diabetes in people.

As you can imagine, dogs have no known inherent need for sugar.

And while Beneful may not be one of Purina’s (a veterinary recommended brand) more “premium” formulas, it has occupied an enormous market share for many years. It was said to be one of Purina’s top selling dog foods in 2016 and fed to more than 14 million dogs at that time.

And so, a company that employs many veterinarians and veterinary nutritionists, was producing a dog food with SUGAR as one of its primary ingredients.

And to take this even further, the same company that was putting sugar in their dog food, was ALSO manufacturing the quite expensive prescription diet for managing diabetes (Purina Prescription DM formula).

In 2016, the company made the decision to take the sugar out of Beneful.

I do not work for this company so I do not know what was happening behind closed doors (maybe veterinarians were complaining about the sugar?)

But the official statement in 2016 of why Purina took out sugar was because of “consumer demands,” which also included a lawsuit against the company by pet owners to take some of these harmful ingredients out.

DCM BLOG SERIES: #2 - The Big Grain Debate

Sugar was not taken out of the dog food because veterinarians thought it might be bad, or because veterinary nutritionists were concerned.

It was taken out because of the growing pressure from pet owners demanding healthier ingredients.

The same trend, incidentally, that led to the creation of Grain Free diets to begin with.

It is situations like these that make me lose some trust towards these companies.

It is not because I don’t believe in the science. I just worry that veterinarians working for these companies have limited influence over the larger, overarching, corporate interests at play.

Interests that include using low quality ingredients.

And while veterinarians do not choose the ingredients, they are taught to defend them.

You will read many statements made by both the companies and veterinarians about the benefits of animal by-products as well as the benefits of ingredients such as corn.

And this makes me worried.


And so this is where we stand today.

I believe the debate about Grain Free vs. Grain Inclusive actually has less to do with grains themselves, but rather centers around the discussion of the quality and types of ingredients used in pet food in general, and the companies that stand behind those choices.

And one of those ingredients, happens to be some grains.

It is likely the name “Grain Free” that has created more confusion than was intended.

At the same time, it is worth mentioning that the Grain Free companies are not perfect either. Blue Buffalo was found to contain animal by products when their labels claimed the opposite, and in 2017, Evangers pet food was found to be contaminated with pentobarbital, the euthanasia drug.

But in general, this is a rare occurrence. Grain Free diets base their entire brand image on the notion that they use high quality ingredients. In this competitive market, they stand to lose a lot when their reputation is tarnished. And so fortunately, this tends to not happen that often.

And while neither of these sides: Grain Free or Grain Inclusive is perfect, I do believe that the Grain Free side is moving us in a good direction and forcing us to have the discussion about what constitutes a healthy ingredient in pet food.

And this, leads us to the topic of grains themselves.

Are grains healthy for dogs?

Let’s take a closer look in blog post #3.

Disclaimer: These blog posts are based entirely on my personal opinions, experience and research. I am not involved with the FDA report in any way or affiliated with any of the brands of dog food discussed in these articles. My intention in writing these posts is to share my opinions how to best feed and care for your animals in light of this developing story.

There is no sponsored content on this website.

However, in order to support my ongoing effort to the public, I use affiliate links, which allow me to receive financial compensation for web traffic through the site. All proceeds go towards maintaining the site and blog. To find out more information about my affiliate links, see my disclosures here.

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