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Last week, Blue Buffalo announced a voluntary recall of “Blue Kitty Yums Chicken Recipe Cat Treats that may contain low levels of propylene glycol.” Source: Food Safety News
The first I heard of propylene glycol was in a warning not to buy baby wipes that had this chemical listed in their ingredients. I was surprised to read it as an ingredient in pet food or treats given all that we've learned about what is safe and isn't safe for our dogs and cats.
What is Propylene Glycol?
I don't know beyond that it's an ingredient in anti-freeze. When I did more homework, I learned that it's actually an ingredient in non-toxic anti-freeze and is approved for use in dog food and treats by the FDA. Despite this news, I still find it shocking to know that something like this could be used as an ingredient in pet food.
Why is Propylene Glycol Used in Dog Food and Treats?
“We use propylene glycol to help keep the semi-moist kibbles soft and moist.” Source: Beneful, FAQs
According to Beneful, propylene glycol is okay to use, because it's not the same as ethylene glycol, which is the anti-freeze used in cars. “Propylene glycol has a different molecular structure, giving it different properties and allowing it to be used safely in animal feed, except for cats, as well as in human foods, such as cake mixes, salad dressings, soft drinks, popcorn, food coloring, fat-free ice cream and sour cream.” Source: Beneful, FAQs
Basically, propylene glycol is a chemical preservative.
Update: Purina has since removed these statements from their website. Possibly as a result of a class action lawsuit, Purina replaced the propylene glycol in their food with a vegetable-based glycerin in response to consumer requests. Source: VeterinaryPracticeNews.com
Is Propylene Glycol Dangerous for Dogs?
Based on my research, it's believed that dogs can't ingest enough propylene glycol in the dog food to be dangerous. I couldn't find any information about how the consumption of propylene glycol consistently over a dog's life will impact their health.
“Propylene glycol ingested at toxic doses can cause central nervous system depression and lactic acidosis, Brutlag says. The oral median lethal dose (LD50) of propylene glycol in dogs has been reported to be ~9 ml/kg body weight. Experimentally, propylene glycol administration in dogs at 2 g/kg/day has caused no adverse effects.” Source: VeterinaryNews.DVM360.com
Symptoms of Propylene Glycol Toxicity in Dogs
Whenever I ask brands about an ingredient in their food that's controversial, I usually hear that the amount is minimal, and the chemical is in human food too. I still worry about the impact to my dog's health over time.
According to the PetPoisonHelpline.com, symptoms of propylene toxicity in dogs include:
- Severe sedation
- Metabolic acidosis (when kidneys aren't able to process excess acids in the body)
Avoiding Dog Food and Treats with Propylene Glycol
There are a plethora of options on the market today; we can easily avoid dog food and treats that contain propylene glycol as an ingredient. I tried to find a list, but I don't think one exists at the moment. I can tell you that you're more likely to come across propylene glycol in soft food and treats.
“Semi-Moist Pouched Food – The reason this type of pet food is so far down the list is because in order for the food to remain “semi-moist,” an ingredient called propylene glycol is added. This is a scary preservative that is a second cousin to ethylene glycol, which is antifreeze. And while propylene glycol is approved for use in pet foods, it is unhealthy for dogs and cats. I do not recommend feeding any food that contains this additive.” ~ Source: Dr. Karen Becker, HealthyPets.Mercola.com
And remember, if you have questions about the food you've chosen for your dog, speak with a dog nutritionist, your veterinarian, or contact the brand directly.