Additives in Dog Foods: Are They Safe?

Understanding the things that are in your dog’s food is an important part of pet ownership. After all, you want the best for your pet, and that means knowing that he’s getting a safe, nutritious diet.

But while most owners are familiar with things like chicken, rice, berries, and carrots, few understand some of the additives present in many dog foods.

But we’re here to help! We’ll share some of the most common and notable additives in dog foods below.

Additives in Dog Foods: The Kinds of Things Manufacturers Add to Dog Food

Additives are included in dog foods for a variety of different reasons, and they each present different benefits and risks.

Some dog food additives are essentially harmless and provide considerable value, while others offer little for your dog and may, in fact, cause problems.

We’ll start by looking at the additives that are usually considered safe and then we’ll shift to those that may present health concerns.

Additives That Are Likely Safe for Dogs

The following additives in dog foods are typically considered safe and should be of little concern to owners. You’ll still want to consult with your vet before selecting a dog food, but these substances are common and unlikely to cause your pet problems.

Natural Flavors

Natural flavors are some of the most common additives used in dog foods. Though they differ, some of the most common natural flavors are simply extracts of natural foods that dogs find tasty. This includes things like chicken, beef, or fish meat, as well as the fats of these (and similar) protein sources.

Some owners may not like that these substances are derived via complicated means, but they’re not anything your dog wouldn’t be eating anyway.

The only caveat to this is that owners of dogs with food allergies or intolerances may need to scan ingredient labels carefully.

For example, if you have a dog who’s allergic to chicken proteins, you’ll want to make sure that the salmon– or venison-based dog food you select doesn’t feature natural chicken flavors, as this could trigger your pup’s allergies.

Natural Preservatives

Canned dog foods don’t usually require preservatives – the anerobic (oxygen-free) environment inside the can helps to prevent the foods from spoiling. Similarly, fresh-frozen foods typically don’t contain preservatives, as they’re kept cold until offered to your dog.

Dry foods, however, are a different story.

The fats and proteins contained in kibble-style foods will eventually spoil, which could make your dog sick. Accordingly, manufacturers often use chemicals called preservatives to prevent kibbles from spoiling.

Generally speaking, preservatives fall into one of two categories: natural and synthetic.

We’ll talk about synthetic preservatives in a bit, but most natural preservatives used in dog foods are widely considered safe.

In fact, a few of the most common naturally occurring preservatives are quite familiar to owners. They may be called a variety of things on ingredient labels, but you’ll know them as vitamin E and vitamin C.

Vitamin & Mineral Supplements

Vitamin and mineral supplements are used by manufacturers to ensure your pup enjoys a healthy, nutritionally balanced diet. And for the most part, they’re considered safe and no cause for worry.

In fact, we know that improperly balanced diets can be harmful to dogs, so an argument can be made that these types of additives are crucial for your dog’s well being.

That said, at least one brand of dog food has devised a way to balance their recipes without the use of supplemental vitamins and minerals. Owners who want to avoid as many dog food additives as possible may want to investigate these recipes.

Probiotics

Probiotics are beneficial microorganisms that are added to dog food with the goal of helping to promote proper digestion and prevent intestinal issues. They may also help with things such as anxiety, though more research is needed.

Most probiotics are bacteria, but there are a few yeasts placed under the same umbrella.

In fact, dogs normally have these kinds of beneficial microorganisms in their intestinal tracts. However, stress, illness, medications, and poor-quality foods may cause their populations to decline. And this, in part, is why manufacturers often include probiotics in dog foods — to help restore proper balance of the gut flora.

Some of the most common probiotic strains used in dog foods include:

• Bacillus coagulans
• Bifidobacterium animalis
• Bifidobacterium bifidum
• Bifidobacterium longum
• Enterococcus faecium
• Lactobacillus acidophilus
• Lactobacillus casei
• Lactobacillus plantarum
• Lactobacillus rhamnosus 

Do note that probiotics are not right for all dogs. Dogs with impaired immune systems should only be given probiotics under a vet’s supervision.

Joint-Supporting Compounds

Joint supporting compounds are another common class of dog food additives that are typically safe for most four-footers.

They are generally included in dog foods to help protect joint cartilage, and some may also help rebuild cartilage that’s been damaged. By and large, these substances are safe for most dogs at the dosages used in dog foods. However, toxicity problems can occur in dogs who ingest too much of these substances. Accordingly, you should always discuss your choice of dog food with your vet.

A few of the most common joint-supporting compounds used in dog foods include:

• Chondroitin: Chondroitin is an element that helps to protect your dog’s joint cartilage from damage. It is typically sourced from cows.
• Glucosamine: Used to help your dog build new joint cartilage, glucosamine can be synthetically created or harvested from shellfish.
• Methylsulfonylmethane (MSM): An anti-inflammatory derived from shellfish or made in a lab, MSM is another joint supplement that’s occasionally incorporated into dog foods.

Additives That May Present Health Risks for Dogs

In contrast to the additives listed above, the following dog food additives may cause health problems for dogs. Note that while some of these have been definitively identified as unsafe, others are not yet backed by data that conclusively demonstrates their potential for harm. Nevertheless, owners often prefer to avoid them until more information is available.

Artificial Flavors

The FDA defines artificial flavors by exclusion – those that don’t fit into the definition of natural flavors are deemed, by default, to be artificial flavors. The verbatim definition is as follows:

The term artificial flavor or artificial flavoring means any substance, the function of which is to impart flavor, which is not derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or similar plant material, meat, fish, poultry, eggs, dairy products, or fermentation products thereof.

Now, artificial flavors are used in a wide variety of foods — including plenty that are in your fridge. So, it’s unlikely that your doggo will eat a bowl of kibble featuring some artificial flavors and then keel over.

But it is possible that the sustained, long-term consumption of artificial flavors may cause problems.

There are a wide variety of artificial flavors and flavoring agents used in some dog foods. The long-term effects of many remain poorly understood. However, there is some research — such as this 2021 study published in Plos One — that demonstrates impaired kidney function in dogs who consumed KH₂PO₄.

So, it just makes good sense to avoid dog foods containing artificial flavors — if for no other reason than the fact that they’re unnecessary! Dog food that’s well-designed and made from high-quality ingredients tastes good already.

In other words, the use of artificial flavors is essentially a low-upside, high-potential-downside proposition.

Artificial Colors

Much of what can be said for artificial flavors also applies to artificial colors. Most of the research carried out thus far has involved rodents, rather than dogs. So, there’s a lot we don’t yet know about the safety of artificial color in dog foods.

But here’s the thing: Artificial colors make even less sense for dog foods than artificial flavors do!

Your dog does not care what color her food is. She probably doesn’t even notice the color of her kibble. Dog food manufacturers use artificial colors to make foods look appealing to you rather than your dog.

Given this, it is simply wise to avoid dog foods containing artificial colors.

Synthetic Preservatives

We already explained that most common natural preservatives are safe. But some synthetic preservatives may cause health problems when consumed over long periods of time.

Now, as we’ve mentioned before (and will do so again), it is important to understand that not all natural ingredients are harmless, nor are all synthetic ingredients harmful.

The world isn’t that simple.

Nevertheless, it is wise to exercise discretion when choosing foods that utilize synthetic preservatives — especially given the fact that natural preservatives are available and known to be safe.

Some of the most common synthetic preservatives include:

• Propylene Glycol — Pet Poison Hotline does list propylene glycol as a toxic substance, however, it only appears to cause problems when consumed in large amounts. Additionally, the FDA categorizes propylene glycol as a GRAS (Generally Recognized as Safe) substance. It is almost certain that the small amounts of propylene glycol included in dog foods will not make your dog sick immediately, but there is some concern about the long-term effects it may cause.
• Ethoxyquin – Ethoxyquin is a common pesticide and it is important to the rubber-manufacturing process, but it is also used in dog foods to preserve fats and prevent the formation of peroxide in canned foods. It is regarded by most authorities as non-toxic, and it is approved for use in animal feeds by the FDA (provided that it is used in the properly identified manner). However, the additive does give some owners pause. One study found that ethoxyquin does cause the accumulation a hemoglobin-related pigment in the liver, as well as increased levels of liver enzymes. These changes appear to be dose-dependent, which means they are unlikely to cause problems in small amounts. Nevertheless, the FDA did recommend that dog food manufacturers reduce the level of ethoxyquin used in dog foods. But – and this is important to note – most manufacturers who use the ingredient already used less than the new guidelines recommend. 
• Butylated Hydroxyanisole (BHA) – Butylated hydroxyanisole is an antioxidant chemical that helps to prevent the oxidation and rancidification of fats. The FDA categorizes BHA as a GRAS (generally recognized as safe) ingredient, provided that it is used in low amounts and properly manufactured. However, there is a not-insignificant amount of evidence demonstrating that BHA causes cancer in some animals. In fact, the U.S. National Institutes of Health (NIH) reports that BHA can reasonably be considered a human carcinogen. The quantities of BHA used in dog foods are quite small (less than 200 parts per million), but because dogs tend to eat the same kibble or canned food on a day-in, day-out basis, it causes some owners concern.
• Butylated hydroxytoluene (BHT) – Butylated hydroxytoluene is another chemical used to prevent the fats in a dog food from spoiling. It is also used in a variety of other applications, ranging from the production of jet fuels to embalming fluid. The fact that it is used in the production of these types of potentially hazardous substances makes some dog owners uncomfortable. In and of itself, the appearance of BHT in these substances shouldn’t matter much – these substances also contain water, and it’s certainly not harmful. BHT has been implicated as a carcinogen in some studies, but it has also been associated with a decrease in cancer risk too (in humans). There isn’t much research studying the effects of the preservative in dogs, but some countries – including Japan, Romania, Sweden and Australia – have banned its use in food. Nevertheless, its use is still permitted by the FDA.
• Propyl Gallate – Propyl gallate is another antioxidant used to prevent the oxidation and rancidification of fats. It is categorized as a GRAS ingredient by the FDA, and it is typically used in relatively low concentrations in dog foods. It has been shown to be mildly toxic when ingested, but the biggest concern about this substance relates to its tendency to act in similar ways to estrogen. It has been shown to be a carcinogen in some human contexts, and it may be detrimental to the reproductive health of those who consume it. Because dogs fed a food containing this preservative would likely receive a significant dose of the substance over a prolonged period of time, many owners prefer to avoid foods containing it.
• Tertiary Butylhydroquinone (TBHQ) – Tertiary butylhydroquinone is another substance that prevents fats from spoiling, and it is used in a variety of foods (including those made for humans and dogs). The FDA permits such use, but the chemical has been shown to potentially cause DNA changes and lead to precancerous growths. However, it has also been shown by one study to potentially prevent cancer. Suffice to say, more research is necessary regarding the safety of this ingredient. However, until more data is available, many dog owners prefer to avoid foods containing TBHQ.

Melamine

Melamine is a nitrogen-rich organic compound used in a variety of industrial applications. It’s used in some plates and eating utensils, it’s one of the primary components of “Magic” erasers, and it’s used in the manufacture of countertops and some furniture. Globally, it’s even used as a fertilizer, though this type of use is not permitted in the U.S.

But unfortunately, it’s also been used by unscrupulous manufacturers in China to help boost the apparent protein content of some foods — including ingredients used in pet foods.

This is very dangerous to dogs, as melamine is toxic and can lead to severe kidney damage. It isn’t like some of the other dog food additives discussed here, which are included for ostensibly benevolent purposes even though they may cause long-term health problems. Melamine is known to be very toxic and is only used to perpetuate fraud.

The potential dangers of melamine contamination were put on full display in 2007, when more than 150 dog food brands found it necessary to initiate voluntary recalls of their foods. This was a frightening time for dog owners, and it caused many manufacturers to look more closely at their ingredient sourcing practices.

As with so many other aspects of dog nutrition, the issue of dog food additives is nuanced.

Several types of dog food additives are not only safe but good for some dogs. Things like joint-supporting compounds and probiotics can help improve the quality of life for the dogs who eat foods fortified with them.

But others may cause long-term harm when fed to pets on a day-in, day-out basis over the course of years. And some, such as melamine, are acutely toxic substances, which should never appear in dog foods.

So, what’s a pet owner to do? How should you choose a dog food?

For starters, stick to foods made by high-quality pet food manufacturers and, to the extent possible, select dog foods that are made in the USA, Canada, Australia, New Zealand, or the European Union. This will help you avoid foods that have melamine or other acutely dangerous substances.

From there, you’ll want to educate yourself about some of the dog food additives that may cause long-term harm — such as those discussed above. Decide which ones you think may be worth avoiding, discuss the issue with your vet, and then try to find a food made without substances that make you uncomfortable.

Hopefully, this will allow you to land on a food that’ll keep your dog healthy and happy for years to come.

Let us know your thoughts about dog food additives in the comments below. We’d love to hear what you think!