The conversation about fillers is everywhere on the internet. At every turn, there seems to be another list of ingredients that supposedly just take up space and don't benefit your dog. But is that really the case? What's the deal with fillers in dog food? To tackle the subject, we take a look at what dog food fillers are, what dog food fillers aren't, and put ingredients to the test.
What are Dog Food Fillers?
Honestly, dog food fillers can be anything that the food trend of the day and the internet-at-large wants them to be. Why? AAFCO (Association of American Feed Control Officials) doesn’t give a definition…since fillers aren’t recognized as “a thing” by the nutrition community. But dog food fillers are worth discussing, which is why we’ve put together a definition combining the main characteristics you’ll see out there:
You may see fillers described as unhealthy ingredients in pet food that have little or no nutritional value, could have been replaced by higher quality alternatives, and aren't biologically appropriate for your dog.
By that definition, fillers are the worst thing in the world, right? (By that definition, we would agree!) Some of Just Right's ingredients are accused of being fillers, but as doting dog owners ourselves, we’re still able to sleep at night. When it comes to such a hotly debated topic, here's our argument: The ingredients typically thought of as dog food fillers (corn, wheat, soy, rice, etc.) don't actually fit the description of "fillers". But don’t just take our word at face value – let's break down the description and see if each of these “filler” ingredients fits the mold.
Do Dog Food "Fillers" Have Nutritional Value? Or Are They Just Empty Calories?
Some self-proclaimed dog food experts slam pet food manufacturers for using ingredients like corn gluten meal to "artificially boost" the protein level in a dog food. In a lot of ways, this is a misleading argument and frankly, misses some key ways in which nutrition works for your dog. For example, corn gluten meal (the ground, milled protein from corn) is a concentrated form of protein, and actually contributes 60-67% protein to your dog's food. While this form of protein is coming from a plant, critics fail to realize that a dog’s body uses protein – whether the protein comes from animals or plants – in the exact same way, so it’s not an artificial boost at all. Your dog gets the quality protein that the ingredient label promises. In fact, including plant-based protein in a dog’s diet actually helps complete all the amino acids they need to thrive, which wouldn’t be possible if using animal-only protein sources.
Nutritional value doesn’t just stop at protein. Corn goes even further beyond the label of a filler with all the benefits it provides – corn gluten meal is an efficient and affordable carbohydrate for energy, provides 3x the amount of protein as chicken, plus fatty acids for healthy skin, coat, and immune system, and a variety of vitamins and antioxidants. When ingredients like corn and rice are ground and processed during the dog food manufacturing process, the carbohydrate inside is highly digestible – think 99.4% digestible for corn and 99.5% digestible for rice.
Veterinarians and animal nutritionists will tell you over and over: looking at the ingredient label does NOT tell you everything you need to know about a dog food. There’s so much more involved in determining what a quality dog food is than just the ingredients. It’s all about the careful balance of all the ingredients working together, providing the nutrients your dog needs. Veterinarian Lauren Pagliughi describes this balancing act and why fillers just don’t make sense:
The term ‘filler’ doesn’t have a place in the pet food industry. It takes an extraordinary amount of work to formulate the right nutrients in the right amounts for complete and balanced nutrition. It would be a waste of money and valuable space to use an ingredient that has no purpose!
THE VERDICT: Do corn, wheat, soy, and other “filler” ingredients have significant nutritional value? YES.
Could "Fillers" be Replaced by Higher Quality Alternatives?
Before we talk about high-quality vs. low-quality ingredients, it’s a good idea to make sure we’re on the same page with what “quality” means. Defining quality may be more involved than you’d initially think. For us, there are a couple different factors that contribute to defining an ingredient as a quality one:
- Is the ingredient safe for your dog? – Both the ingredient itself and the amount that's included in the food should be edible and species-appropriate. (Chocolate, for example, isn’t edible for dogs.)
- Is the ingredient wholesome? – The wholesomeness of an ingredient means that it isn’t contaminated, rotten, rancid, etc., and that it's in great condition and suitable for use in food. As ingredients buyer Viktoriya and food safety supervisor Dan can tell you, we’ve got some of the strictest standards for wholesomeness and safety in the industry to help prevent and catch any unwholesomeness. Between multi-step audits on our ingredient suppliers’ sanitation and safety practices, routine purity tests in our own labs, and much more, Purina conducts 30,000 checks involving ingredients, packaging, receiving, processing and packing in a typical 24-hour production. We worry about ingredient wholesomeness so you don’t have to.
- Is the ingredient nutritious? – To us, your dog has a checklist of nutrients, amino acids, etc. he needs to be healthy. So with each ingredient we select, we ask ourselves: Does the ingredient offer nutrients that efficiently contribute to that checklist? Can your dog’s body digest the ingredient so that the nutrients can be used?
If the answer is “yes” to all of the above, then you’ve found yourself a high-quality ingredient!
These criteria are applied to every ingredient, and every ingredient we use qualifies as high-quality, otherwise, we don’t use it. And yet, many dog owners are interested in other ingredients they perceive as higher quality; maybe because they’re more novel? More exotic? But are these ingredients really any better quality than the so-called dog food “fillers” they’re replacing? The science says no. Quality ingredients are quality ingredients if they’re checking all the boxes that your dog needs and part of a complete and balanced diet. Ingredients like corn and wheat that you’re familiar with may not be as exciting as pumpkin or kale, but in terms of ingredient quality, the only difference between corn and pumpkin is the name.
THE VERDICT: Are corn, wheat, soy, etc. quality ingredients? YES.
Are Dog Food "Fillers" Biologically Appropriate?
How do you determine if a diet is biologically appropriate? Above everything else, the diet must provide the nutrients that your dog needs. And how can you tell that it does? That’s where the concept of digestibility comes into play. Digestibility is all about how much of the nutrients your dog’s body can absorb from his food. (In other words, how much of the food your dog’s body uses vs. how much shows up in the poop bag.) If a large portion of a food’s nutrients are getting used, as illustrated by a small pile of poop compared to the amount of food eaten, then there’s really no room left for fillers – unused, indigestible, space-wasters?
Research has shown time and time again that many of the ingredients that are villainized as “fillers” actually provide vital nutrients for your dog. So when a diet contains ingredients like corn, wheat, and soy, and you’re seeing good results in the back yard, rest assured that those ingredients are contributing to an efficient, nutritious, and digestible diet…they’re not just taking up space in the food and coming out the back end. ;)
THE VERDICT: Can a dog food diet that contains so-called “filler ingredients” like corn, wheat, soy, etc. be highly digestible and biologically appropriate? YES.
So…Is Your Dog Food Full of "Filler" Ingredients?
Definitely not. If fillers are ingredients that serve no purpose for your dog, then it would be pointless to include them in the first place. If you'd like to exclude corn, wheat, and soy from your dog's personalized blend, that's entirely your choice, and you can do that! Just know that those ingredients aren't dog food fillers.
At Just Right by Purina, every ingredient and every nutrient works together so that your dog's diet is complete and balanced, and designed to help him live happy and healthy. It's simple: We believe in nutrition with purpose.
Ready to create your dog’s ideal blend?