Ethoxyquin in Dog Food - Dog Nutrition DB

Ethoxyquin in dog food is a synthetic preservative. However, due to its controversial status and potential adverse health effects, we as dog lovers should be aware of the risks.

Contents

What is Ethoxyquin?

Ethoxyquin is a synthetic antioxidant that used in the preservation of food and feeds, including dog food, for decades.

It’s used worldwide to stabilize all kinds of raw materials.

This brownish liquid was first used as a rubber stabilizer, then in pesticides, and can prevent color loss in spices like chili and paprika.

It was developed by Monsanto in the 1950s and approved as an additive to pet food in 1959.

Ethoxyquin works by reducing oxidative damage to fats and other substances in feed by quenching free radical formation.

Without preservation, fats can go rancid, making the food smell or taste bitter, nutritionally deficient, or even toxic.

Ethoxyquin is cheap, even more effective than BHA or BHT, suppresses the toxic effects of degraded fats, and helps to preserve the freshness of the product^[3].

Ethoxyquin in Dog Foods

Ethoxyquin cannot be used in any food for human consumption (except to preserve color in spices).

But this synthetic additive is widely used in the US to preserve pet foods directly or its ingredients like fish meal or animal fats.

Ethoxyquin has been used in animal feed since 1959 and is approved for use in pet foods in the US. The maximum allowable concentration for dog food is 150 mg per kg of complete food^[8].

Most pet foods don’t seem to exceed 75 mg/kg anyway.

It is added to dog food as a preservative to prevent the oxidation of carotenoids and essential nutrients. In canned pet food, it prevents the formation of organic peroxides.

Preservatives are a necessary evil found in almost all commercial dog foods. And yes, there are more natural alternatives.

But ethoxyquin is cheap and way more potent than tocopherols, ascorbic acid or rosemary extract.

Is Ethoxyquin Bad For Dogs?

Owner reports of adverse effects to ethoxyquin in dog food have been on the rise since the late 1980s^[1].

Reported signs included organ dysfunction, cancer, allergic reactions, and a host of skin and hair problems. But these were all just based on “anecdotal evidence”.

Today, we definitely know that ethoxyquin is really something that you shouldn’t feed on a daily basis.

But as of now, the US and EU authorities disagree.

In the European Union, ethoxyquin was approved for a long time as a feed additive (E 324) despite a lack of evidence for its safety.

In 2015, authorities guesstimated a safe maximum content of 11 mg per kg of complete food for dogs.

[…] no conclusion on any safe level in feed can be made for target animals, particularly for those fed the additive for their lifetime, such as dogs and cats […]
EFSA 2015^[4]

But since then, the industry still failed to provide solid proof that ethoxyquin is safe and does not have an adverse effect on animal health, human health, or the environment…^[6]

So in 2022, ethoxyquin was banned as a feed additive in the EU^[7]!

According to EFSA, ethoxyquin itself is not genotoxic or carcinogenic and does not cause developmental toxicity.

In low doses, ethoxyquin seems to be reasonably safe.

So why did the EU ban it?

Well, although Ethoxaquin itself seems safe, it contains the mutagenic p-phenetidine (or: 4-ethoxyaniline), a possible mutagen with high renal toxicity^[4,5].

And the finished chemical preservative sold as ethoxyquin always contains some residue of this harmful compound.

Additionally, ethoxyquin is rapidly absorbed and is transformed into other chemicals such as ethoxyquin N-oxide, ethoxyquin quinone imine, or ethoxyquin dimer.

Ethoxyquin dimer and other ethoxyquin residues accumulate in animal fat tissue over time, which is an obvious safety concern.

To make matters worse, dogs seem to be one of the most susceptible animals to the adverse effects of ethoxyquin^[3]!

At experimental high doses, ethoxyquin can cause weight loss, liver and kidney damage, changes in the digestive tract, and oddly colored urine, skin, or coat in dogs^[3].

The US authorities don’t deny its potentially harmful effects (pet food manufacturers still do, of course). But despite the search for better compounds, ethoxyquin is still without alternative the cheapest and most effective antioxidant on the market.

Luckily, the food label of products made with this additive must bear a statement that clearly indicates if the product contains ethoxyquin^[8,9].

So it’s easy to avoid this additive and its possible side effects. And it certainly won’t hurt if we as consumers force the hand of pet food manufacturers to ditch it for good...

What is Ethoxyquin?

Ethoxyquin in Dog Foods

Is Ethoxyquin Bad For Dogs?

Further Reading