The leaves room turning, the days are getting much shorter and over there is a identify nip come the air, signalling that it’s time to get our cars all set for the ice and cold. Antifreeze is crucial ingredient for a functional automobile during Canadian winters, yet what’s an excellent for cars deserve to be a catastrophe for wildlife. At the BC node the the CWHC we view a few cases of deadly antifreeze toxicity each year in a range of wildlife ranging from floor squirrels and raccoons to bears and also coyotes.

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The vast majority of antifreeze is made up of 95% ethylene glycol, which is diluted to 50% in vehicle cooling systems. Ethylene glycol is exceptionally toxic to every animals, consisting of humans. Less than a tespoon (5mL) the undiluted antifreeze is enough to death a cat, and also less than a quarter cup (125 mL) can kill one adult human. Not only is it dangerous come wildlife due to the fact that it is toxic in small amounts, but it additionally tastes sweet, and has a low freezing allude so the is liquid once water is ice, i beg your pardon attracts pets to consume it. To help deter consumption by children, the BC government has compelled a “bittering agent” to be included to antifreeze since 2011, however the impacts of this on intake by wild pets is unknown.

The most typical clinical indicators reported in instances submitted to the CWHC BC space neurological signs such together incoordination, challenge moving the hind end, and sometimes seizures. One raccoon was submitted through a history of “unusual friendliness”.


Once ingested, ethylene glycol is promptly absorbed, reaching top blood concentrations in about three hours. Symptoms because that this duration are mild, generally resembling intoxication v alcohol. End the course of the next several hours ethylene glycol is metabolized through the liver and kidneys, and also that is as soon as it becomes a real problem. Build-up of among the metabolites, glycolic acid, results in a significant metabolic acidosis (decreased blood pH) and renal tubular necrosis (kidney failure). Buildup of a later on metabolite, oxalate, also contributes come renal tubular necrosis and also is deposited as crystals in the renal tubules. The result is deadly in a few hours to days.

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Figure 1: Kidney of a be afflicted with that passed away from ethylene glycol (antifreeze) toxicity. Note the damaged renal tubules containing numerous bright crystals that shine under polarized light. H&E – polarized light

Careful storage, handling and also disposal of antifreeze as well as switching come antifreeze that contains propylene glycol, which is much less toxic, are all methods to decrease the threat of antifreeze toxicity in people, pets and also wildlife. The best disposal is recycling. In BC we are fortunate the there room 339 depots throughout BC that will take your unwanted or provided antifreeze; discover one close to you HERE (and across Canada HERE).