Propylene glycol is found in many household products and has a significant toxic risk if ingested by pets. Of note, it is commonly found in ‘pet-safe’ anti-freeze products. While this form of anti-freeze is less toxic than those containing ethylene glycol, these products still pose a risk to pets if ingested.

Propylene glycol can also be found in RV antifreeze, hair dyes, disinfectants, paints and varnishes.

Signs and symptoms of toxicity: Initial signs of toxicity include depression, weakness, involuntary muscle movements, increased urination, and increased thirst. Low blood pressure, cardiovascular collapse, and seizures can also occur. There is a risk of lactic acidosis and Heinz body anemia (in cats) developing later.

Toxic consumption: In dogs, 9 mL/kg (4.1 mL/lb) can be fatal. There is no established toxic threshold in cats. All incidents of accidental consumption should be reported.

Dogs: Elemental Iron Toxic Consumption
X-Small Yorkie, Chihuahua	Small Pug, Boston Terrier, Poodle	Medium Beagle, Scottish Terrier	Large Boxer, Cocker Spaniel	X-Large Retriever, German Shepherd	XX-Large Great Dane, St. Bernard
1 – 10 lbs. (0.45 – 4.6 kg)	11 – 25 lbs. (5 – 11.4 kg)	26 – 40 lbs. (11.8 – 18.2 kg)	41 – 70 lbs. (18.6 – 31.8 kg)	71 – 90 lbs. (32.3 – 40.9 kg)	91 – 110 lbs. (41.4 – 50 kg)
> 4 mL	> 44 mL	> 106 mL	> 167 mL	> 290 mL	> 372 mL

References:
Osweiler, G, et al. (2011). Blackwell’s five-minute veterinary consult clinical companion. Small Animal Toxicoloty. [Kindle version]. Retrieved from Amazon.com