Propylene Glycol in Dog Food - Dog Nutrition DB

Propylene glycol in dog food is a synthetic substance used to maintain moisture in semi-moist dog foods and treats.

Contents

What is Propylene Glycol?

Propylene glycol is a slightly syrupy synthetic liquid. It is odorless and colorless with a faintly sweet taste.

It absorbs water and can be used to maintain moisture in foods.

This makes it a preservative since it keeps water away from microorganisms and inhibits the growth of mold and fungi.

Propylene glycol is commonly used as a food additive.

In the European Union, it is given the E-number E1520 and is used as a humectant for food applications. The FDA considers it an emulsifier and general-purpose additive.

Both consider it as safe when used in reasonable amounts.

Propylene glycol is often used as a solvent and carrier for colors and flavors, enzymes, and nutrient supplements.

It is then carried over indirectly to the final food.

The substance can be found in many foods, cosmetics, and pharmaceuticals such as soda, salad dressings, fast food, marshmallows, baking mixes, confections, frostings, dairy products, seasonings, make-up, hand sanitizers, etc.

In addition to its use in food products, propylene glycol is also used in many industrial applications, as an antifreeze or as a carrier liquid in electronic cigarettes.

In semi-moist dog food and treats, it is used as a humectant, shelf-life extender, sweetener, and stabilizer.

However, it has become a controversial ingredient in dog food as it causes adverse effects in cats and was banned for use in cat food.

But only some brands of semi-moist dog food use propylene glycol, while it is a little more common in soft dog treats.

Is Propylene Glycol Safe For Dogs?

Propylene glycol is a chemical food additive but is generally considered safe for use in food.

Some people are allergic to propylene glycol and high doses can be toxic. But most reported cases of propylene glycol toxicity have resulted from an accidental overdose from intravenous medications.

That’s not the same as eating it in small amounts.

Propylene glycol also has a bad reputation due to its use in antifreeze. And everybody knows that antifreeze is toxic to dogs, right?

However, exposure to household chemicals is not the same as consuming tiny amounts of a food additive, either.

Propylene glycol should also not be confused with ethylene glycol, a far more toxic ingredient in many antifreeze products.

Last but not least, propylene glycol is also known to cause adverse effects in cats, which has led to its ban for use in cat food.

While the oral toxicity of propylene glycol for dogs is very low, cats seem to be particularly susceptible to adverse effects^[5].

In cats, this food additive is linked to the formation of Heinz bodies and a reduced lifespan of red blood cells leading to hemolytic anemia. By the way, this is also what happens when you feed too many thiosulfates from concentrated onions or garlic to dogs or cats.

Heinz bodies are little clumps of damaged hemoglobin within red blood cells that can be seen under the microscope.

Dogs tolerate propylene glycol way better than cats, but liver or kidney disease may reduce their tolerance.

And dogs are not immune to the effects of propylene glycol. Long-term feeding of high doses has been shown to also cause some dose-dependent hematological changes in dogs.

Dogs that were fed up to 5.000 mg/kg body weight per day showed increased red blood cell destruction accompanied by an accelerated compensatory increase in the production of new red blood cells in the bone marrow. But there were no other adverse effects.

However, in moderate doses, propylene glycol is considered safe for dogs. The main risk factor is accidental exposure to large amounts far in excess of those found in dog food products.

What happens when your dog eats dog food with propylene glycol?

Once ingested, this substance is quickly absorbed in the gastrointestinal tract and widely distributed to organs and tissues.

Some of it gets excreted by the kidneys, but a large portion is metabolized in the liver into harmless compounds such as lactic acid and pyruvic acid that can be further metabolized into a source of energy and ultimately into carbon dioxide and water.

Thus, there should be no cumulative effect, and there is no evidence of concern for genotoxicity or carcinogenicity.

It is very likely that your dog has some dietary exposure to propylene glycol since it can be added indirectly as part of other ingredients.

If your dog is on a static diet, meaning you feed the same stuff daily, it is far from a wholesome ingredient. I mean, if you worry about garlic in dog food you should probably also worry about propylene glycol.

But both are harmless when consumed in small amounts.

In summary, occasional exposure to propylene glycol in dog treats is not a cause for concern. Many of us use semi-most dog foods as training rewards, which is also not a problem.

Soft dog food has to be preserved somehow, right?

And propylene glycol reduces the amount of other preservatives that manufacturers would use in its place.

While propylene glycol is generally considered safe for use in dog food, its also not a necessary ingredient and is easy to avoid.

We recommend that you limit your dog’s exposure to propylene glycol in his daily food but don’t worry too much about it.

What is Propylene Glycol?

Is Propylene Glycol Safe For Dogs?

Further Reading