Is Glycerin Bad for Dogs?

Glycerin is a common ingredient and one that gets a bad rap, leading many pet parents to start typing “Is glycerin in dog treats bad for dogs?” or even “Can glycerin kill dogs?” into their search engine of choice.

People are wary, despite the FDA declaring glycerin as safe ¹ when used following good manufacturing practice. Of course, such caution is valid and wise — pet parents must understand what’s in dog food and know which ingredients to avoid.

However, glycerin isn’t as bad as you might think, which is why we’ve written this article to explain everything you need to know about glycerin in dog treats and beyond.

What is glycerin?

Glycerin, also known as glycerol, is a sugar alcohol that is odorless, colorless, and sweet-tasting. The FDA has declared it safe for human consumption and is commonly used in foods, soaps, medicines, and skin products. 

This syrupy liquid compound is derived from animal fats, certain plant oils, or petroleum. As a by-product of soap and biofuel production, its abundant supply has driven efforts to find alternative uses, including its incorporation into animal feeds. ² 

It’s also used in many dog treats and dog foods.

Types of glycerin

There are two different types of glycerine: vegetable (natural) and petrochemical (synthetic). 

Natural glycerin is derived from oils and fats from sources including coconuts or oil palms. Synthetic glycerin can be petroleum-based and produced from propylene.

Natural glycerin made from rapeseed oil is a common plant-based source of glycerin and is most commonly used in dog products. 

Why is glycerin in dog treats and food?

Glycerin is mainly used as a humectant to bind the ingredients into a soft, chewy treat. 

“You find glycerin primarily in semi-moist or soft-bake foods and treats. Its role as a humectant is to bind water in the food,” says Laura Ward, DFA’s nutritionist. “Without a humectant like glycerin included the food would quickly become moldy. 

“It has to do with water activity, which is the availability of moisture within a food. Glycerin reduces the water activity and helps to stabilize the product in that soft, chewy texture.”

It’s also in pet grooming products (and human ones) to help moisturize and protect the skin.

What are the benefits of glycerin for dogs?

Glycerin, while not necessarily nutritious, still offers benefits when included in dog products. 

As mentioned, one of glycerin’s primary advantages is its role as a humectant, meaning it attracts and retains moisture. Similarly, in pet foods, glycerin helps maintain a moist, chewy texture, preventing the food from drying out or becoming moldy.

Glycerin also has several medical applications. It can function as a laxative ³  and is used to help relieve pressure due to conditions like glaucoma and brain swelling. 

Concerns about glycerin in dog treats

Pet parents may remember and refer to the Chinese-made jerky incident a few years back where dog treats were associated with serious illness and death in dogs. 

After a thorough investigation, the FDA got involved and discovered the manufacturers were using glycerin potentially sourced from a plant called Jatropha which can contain toxic by-products like phorbol esters.

Due to its high oil content and relatively low cost, the plant has recently become an attractive source material for making biodiesel.

These compounds exhibit acute and chronic toxicity to both humans and animals when ingested. The key takeaway from this incident is to read the ingredient list carefully to ensure there are no traces of Jatropha or other concerning ingredients before offering your dog new treats or food.

Is glycerin bad for dogs?

Despite some negative press, glycerin has been deemed non-toxic and safe for animals when sourced as food-grade and used in proper concentrations. Unless advised otherwise by your vet, glycerin in pet food is considered safe.

There was a small study that explored the effects of the oral administration of glycerol on blood glucose levels in dogs, suggesting glycerin-containing products may be unsuitable for diabetic canines. However, the glycerol amounts used in the study were much higher than those found in food or treats. ⁴. 

Does glycerin have any side effects on dogs?

In very large amounts, vegetable glycerin can cause some gastric discomfort, like cramping, gas, and diarrhea. This would only occur if a pet ingested an inappropriately large amount of vegetable glycerin, and would not happen through glycerin entering the diet through treats or foods.

What are the signs of glycerin toxicity in dogs?

With toxicology testing, there have been no adverse effects on DNA or cancer-causing properties, although the tests were conducted on rats, rabbits, and guinea pigs. 

As with any ingredient, dogs can have individual adverse reactions. Small amounts of glycerin can cause rare allergic reactions or trigger nausea and vomiting in some dogs. As always, consult your veterinarian if you have any concerns. ⁵  

If your dog ingests contaminated glycerin, watch out for adverse reactions such as vomiting, diarrhea, lethargy, and loss of appetite. Seek immediate medical attention if any of these symptoms occur.

Overall, glycerin has not been named as a toxic ingredient and when consumed moderately, it is safe for your dog. Although it’s not necessarily a nutritious ingredient, it can help bind tasty treats and food for your dog to gobble up.