Antifreeze Poisoning in Dogs and Cats: Why Hours Matter
Quick answer
Treat it as an emergency. Antifreeze tastes sweet, a few teaspoons can cause kidney failure, and Pet Poison Helpline says cats need treatment within 3 hours and dogs within 8. Phone a vet now, even if your pet seems fine.
Taken from this page and its sources. Not veterinary advice. If your pet has already eaten some and seems unwell, see who to call.
Think your pet has drunk or licked antifreeze? Phone your vet, an emergency vet or your national animal poison line now, even if your pet seems fine or seems to be getting better. Do not wait for signs. Find an emergency vet
This page is not veterinary advice. There are no treatment steps here, on purpose: antifreeze poisoning is treated by a vet, and the only useful thing to do at home is to get there quickly. Full disclaimer.
Antifreeze is one of the few poisons where the clock matters more than almost anything else. It tastes sweet, so animals drink it readily, and a small amount is enough to damage the kidneys. The treatment that works has to start within hours, often before a pet looks seriously ill. Sources: Pet Poison Helpline, Antifreeze poisoning; Merck Veterinary Manual (pet owner version), Ethylene glycol (antifreeze) poisoning, G. F. Grauer, updated September 2024.
On this page (6 sections)
Why it is so dangerous
Most antifreeze is ethylene glycol. The Merck Veterinary Manual says most poisonings come from radiator antifreeze, and points to its sweet taste and small lethal dose. Pet Poison Helpline says it can take as little as a few teaspoons for kidney failure to develop, and that because of the sweet taste pets will readily drink large quantities. Sources: Merck Veterinary Manual (pet owner version), Ethylene glycol (antifreeze) poisoning, G. F. Grauer, updated September 2024; Pet Poison Helpline, Antifreeze poisoning.
The clock
Pet Poison Helpline says cats must receive treatment within 3 hours of drinking antifreeze, and dogs within 8 hours. Merck says the antidote in dogs only works if it is given before kidney failure develops, and that the outlook worsens as more time passes between drinking it and treatment. That is why vets ask you to come in straight away, not when signs appear. Sources: Pet Poison Helpline, Antifreeze poisoning; Merck Veterinary Manual (pet owner version), Ethylene glycol (antifreeze) poisoning, G. F. Grauer, updated September 2024.
Signs, and the false recovery
Merck says signs start almost immediately and look like alcohol poisoning: vomiting, intense thirst, heavy urination, then depression and wobbliness. It says dogs may seem to improve for a while about 12 hours after drinking it, and that severe kidney failure usually develops between 36 and 72 hours in dogs and between 12 and 24 hours in cats. Pet Poison Helpline describes the same stages, with a faster heart and breathing rate at 12 to 24 hours and kidney failure at 24 to 72 hours. A pet that seems better has not shown that it is better. Sources: Merck Veterinary Manual (pet owner version), Ethylene glycol (antifreeze) poisoning, G. F. Grauer, updated September 2024; Pet Poison Helpline, Antifreeze poisoning.
Where pets find it
Pet Poison Helpline points to cars leaking in the garage and unidentified puddles. Merck adds some brake and transmission fluids and some heat-exchange fluids, and notes that cats can be poisoned through the skin by some topical products. Winter makes all of it more common: radiators are topped up, and puddles sit on driveways and roads. Sources: Pet Poison Helpline, Antifreeze poisoning; Merck Veterinary Manual (pet owner version), Ethylene glycol (antifreeze) poisoning, G. F. Grauer, updated September 2024.
Prevention
Merck advises storing antifreeze securely, throwing away old containers, and cleaning up leaks straight away, then covering the spot with something absorbent such as cat litter or sawdust. It says antifreeze made with propylene glycol is less toxic than ethylene glycol and lacks the sweet taste, so animals are less drawn to it; the label says which one you are buying. Source: Merck Veterinary Manual (pet owner version), Ethylene glycol (antifreeze) poisoning, G. F. Grauer, updated September 2024.
- Keep containers closed, upright and on a high shelf.
- Top up radiators with pets indoors, and wipe up every drip.
- Check under the car for leaks, and keep pets away from puddles on driveways and roads in winter.
Where these facts come from
- Merck Veterinary Manual (pet owner version), Ethylene glycol (antifreeze) poisoning, G. F. Grauer, updated September 2024, read 6 November 2026.
- Pet Poison Helpline, Antifreeze poisoning, read 6 November 2026.
Sources last checked 6 November 2026. Spotted something out of date? Tell us.
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