Anti-freeze (ethylene glycol) poisoning is a little-known danger to cats that is much more common in winter months. The chemical is sweet tasting and odourless. Cats encounter ethylene glycol via anti-freeze and water coolant leaks and spills as well as accumulations in puddles and run-off water. Due to its sweet taste, cats will voluntarily drink spills of the chemical as well as lick it from their paws after walking across contaminated surfaces. Once ingested, the liver will convert ethylene glycol into toxic by-products which damage the kidneys.  Even tiny amounts of ethylene glycol can cause rapid kidney failure in cats which is often fatal.

Some signs of poisoning from antifreeze can show as soon as 30 minutes after ingestion but it can take a couple of days for kidney failure to become apparent.

Stage 1 (within 30 minutes to 12 hours of ingestion):

The cat may look “drunk.” Additional signs include vomiting, lethargy, loss of coordination, drinking more, seizures (fits), and coma.

Stage 2 (12 to 24 hours after ingestion):

At this point, some cats can improve, leading owners to think the cat is better. However, cats are dehydrated, with increased heart and breathing rate in this period.

Stage 3 (12-24 hours after ingestion):

By this point, sadly irreversible kidney failure may occur. Depression, lethargy, lack of appetite, vomiting, seizures, coma, and death may be seen


Your vet will examine your cat and if anti-freeze toxicity is suspected and a blood test will be taken to check for damage to the kidneys. Damage to the kidneys is irreversible so the prognosis is poor if changes are noted on the blood tests. Urine can also be assessed for specific crystals associated with ethylene glycol poisoning.


Cats that have ingested ethylene glycol or are suspected to have, will be started on a drip to help support the kidneys. Other supportive therapy and intensive care is also often necessary such as assisted feeding. Unfortunately, the toxicity is fatal to most cats, however rapid treatment can increase chances of survival.

If you suspect your cat has encountered antifreeze or leaked water coolant, please book in to see your vet as an emergency.