Antifreeze Poisoning in Dogs and Cats: Signs and Treatment

Antifreeze poisoning in dogs and cats is a true emergency that is most common in the colder months. Most engine coolant is based on ethylene glycol, which is poisonous to pets in small amounts and tastes sweet, so a dog may lap at a driveway puddle or a cat may lick a garage drip. This guide covers symptoms, timeline, treatment and prevention.

A black and white cat looking over a wooden ledge — Photo: Unsplash

Key Takeaways

Ethylene glycol is highly toxic, and cats are harmed by smaller amounts than dogs.
Early signs look like drunkenness; a pet may then seem better while the kidneys are damaged.
Antidotes (fomepizole or medical ethanol) work only if a vet gives them within hours.
There are no safe home remedies. Do not give alcohol or make your pet vomit; call a vet or poison line.
Store coolant securely, clean spills at once and consider propylene glycol products.

What Is Ethylene Glycol and Why Is It Toxic?

Ethylene glycol is a sweet-tasting liquid that is the main ingredient in most car antifreeze. The body converts it into acidic by-products. According to the Merck Veterinary Manual, one of these, oxalic acid, forms calcium oxalate crystals in the kidneys, leading to acute kidney failure.

The ASPCA notes that ethylene glycol affects both the nervous system and the kidneys, so ethylene glycol poisoning in dogs and ethylene glycol poisoning in cats follow the same pattern: early neurological signs, then kidney injury. Our cat kidney disease guide explains why kidney damage is so serious.

Where else is ethylene glycol found?

Car coolant is the main source. The ASPCA also lists toilet winterising products, some inks, snow globes, the bases of portable basketball hoops and some household paints, and the Merck Veterinary Manual adds some brake and transmission fluids. Our household chemicals guide covers other garage products to keep out of reach.

How Much Antifreeze Is Toxic to Dogs and Cats?

A small amount can cause serious harm, and cats are more sensitive than dogs. The Merck Veterinary Manual gives the minimum lethal dose of undiluted ethylene glycol as about 1.4 mL per kg of body weight for cats and 4.4 to 6.6 mL per kg for dogs.

Sources vary: the Pet Poison Helpline says as little as a teaspoon can be fatal for a cat and a tablespoon or two for a dog, depending on size. Never use these figures to decide whether to wait. Any suspected antifreeze ingestion in dogs or cats needs a vet straight away.

Antifreeze Poisoning Symptoms in Dogs and Cats

Early antifreeze poisoning symptoms in dogs and cats look like alcohol intoxication: wobbliness, vomiting, extra drinking and urination, and dullness, starting as soon as 30 minutes after ingestion. Later, as the kidneys fail, a pet may stop eating, produce little urine and collapse. Signs reported by the ASPCA, Pet Poison Helpline and Merck include:

Stumbling, poor coordination or appearing “drunk”
Vomiting and drooling
Increased thirst and urination early on
Low energy, loss of appetite and dehydration
Little or no urine as kidney failure develops
Seizures or coma in severe cases

These signs have many possible causes (see our signs your pet is sick guide), but if your pet may have had access to antifreeze, do not wait for them to appear.

Antifreeze Poisoning in Dogs Timeline and Cats Timeline

The antifreeze poisoning symptoms timeline has three broad stages. The Pet Poison Helpline describes stage 1 from about 30 minutes to 12 hours, a deceptive stage 2 around 12 to 24 hours, and stage 3 kidney failure at 12 to 24 hours in cats and 36 to 72 hours in dogs.

Stage	Time after ingestion	What you might see
Stage 1: drunk-like signs (dogs and cats)	About 30 minutes to 12 hours	Stumbling, vomiting, drooling, extra thirst and urination, dullness, sometimes seizures
Stage 2: apparent improvement (dogs and cats)	About 12 to 24 hours	The pet may seem better, but damage inside the body continues
Stage 3: kidney failure (cats)	About 12 to 24 hours	Lethargy, vomiting, not eating, little or no urine, collapse
Stage 3: kidney failure (dogs)	About 36 to 72 hours	Lethargy, vomiting, not eating, little or no urine, collapse
Time ranges as described by the Pet Poison Helpline and the Merck Veterinary Manual. Individual pets vary.

The antifreeze poisoning in cats timeline is much shorter than in dogs. The stage 2 “recovery” is the trap: the worst may seem over just as the antidote window closes.

What Should I Do If My Pet Drank Antifreeze?

Treat it as an emergency even if your pet seems fine. Call your vet or nearest emergency clinic immediately, contact a pet poison helpline while you travel and bring the product label. Do not try any home treatment.

Call a vet or emergency clinic now. Say you suspect antifreeze and roughly when.
Contact a poison helpline. In the United States, the ASPCA Animal Poison Control Center is (888) 426-4435 and the Pet Poison Helpline is (855) 764-7661. Both operate around the clock, and a consultation fee may apply.
Take the packaging. The ASPCA advises this so the vet can check ingredients.
Do not give food, drinks, alcohol or medicines, and do not try to make your pet vomit unless a vet or poison line tells you to.

Our pet poison emergency guide, dog first aid guide and cat first aid guide help you prepare in advance.

Are There Home Remedies for Antifreeze Poisoning in Dogs?

No. There are no safe or effective antifreeze poisoning in dogs home remedies, and the same applies to cats. The antidote and supportive care must come from a veterinarian, usually in hospital. Home remedies such as forcing vomiting can cause harm, for example if a drowsy pet inhales vomit, and they waste the short window in which treatment works.

Antifreeze poisoning in cats and vodka: should I give my pet alcohol?

No. Never give a cat or dog vodka or any other alcohol at home. Vets do use ethanol as an antidote, but it is given into a vein in measured amounts with close monitoring, and the Pet Poison Helpline notes that pets receiving it must be hospitalised. Alcohol given at home can cause alcohol poisoning and inhaled vomit, and it delays real treatment.

Antifreeze Poisoning in Dogs Treatment: How Do Vets Treat It?

Vets test for exposure where possible, then give an antidote, fomepizole or ethanol, to stop the body making toxic by-products, plus intravenous fluids to support the kidneys. Timing is critical: the Pet Poison Helpline says treatment should start within about 8 to 12 hours for dogs and 3 hours for cats.

Testing. In-clinic kits detect ethylene glycol in blood for a limited time after ingestion; Merck notes vets may treat on suspicion if no reliable test is available.
Decontamination. Very soon after ingestion, a vet may empty the stomach in the clinic.
Antidote. Fomepizole (4-MP) or ethanol blocks the conversion of ethylene glycol into its toxic products.
Fluids and monitoring. Intravenous fluids and checks on kidney values and urine output in hospital.

What is the antifreeze poisoning in cats antidote?

Cats are treated with the same two antidotes as dogs: fomepizole or ethanol, given intravenously by a vet. The Merck Veterinary Manual describes a higher-dose fomepizole protocol for cats as extra-label use, and notes ethanol as an option. Either must be started very early, ideally within 3 hours, to work well.

The Pet Poison Helpline calls fomepizole the preferred antidote, but it can be costly and not every clinic stocks it, so some vets use ethanol.

What Is the Antifreeze Poisoning in Cats Prognosis?

The prognosis depends mostly on how quickly treatment starts. Cats given the antidote before the kidneys are damaged have the best chance. According to the Pet Poison Helpline, a delay beyond about 3 hours in cats (8 hours in dogs) leads to a poor prognosis, and both it and the Merck Veterinary Manual describe the outlook as poor once kidney failure develops.

Antifreeze poisoning in kittens and puppies

The Merck Veterinary Manual notes that younger animals may be more susceptible to ethylene glycol. Kittens and puppies are small and curious, so any possible exposure needs a vet straight away.

Antifreeze Toxicity in Dogs and Cats: Ethylene Glycol vs Propylene Glycol

Propylene glycol is an alternative antifreeze ingredient that is much less toxic to pets than ethylene glycol. The ASPCA says it has a much wider margin of safety, and the Merck Veterinary Manual notes it lacks the sweet taste. It is still not harmless.

Feature	Ethylene glycol antifreeze	Propylene glycol antifreeze
Toxicity to pets	High; small amounts can be fatal	Much lower, but can still cause illness
Taste	Sweet, attractive to pets	Not sweet, according to Merck
Main risk	Acute kidney failure	A milder poisoning with a usually better outlook
Antidote treatment needed	Yes, urgently	Vet assessment still needed after any exposure

Does the bittering agent make antifreeze safe?

No. A bittering agent may discourage some animals but does not remove the poison. In December 2012, the Humane Society Legislative Fund and the Consumer Specialty Products Association announced that makers would voluntarily add denatonium benzoate to consumer antifreeze across the US; seventeen states already required it by law. The Merck Veterinary Manual notes bittered products may still appeal to some animals.

How to Prevent Antifreeze Poisoning in Dogs and Cats

Store it securely in the original, closed container, high up or locked away.
Clean spills at once. Merck and the Pet Poison Helpline suggest covering spills with cat litter or sawdust, then disposing of it safely.
Check your vehicle. Look for drips under your car and have leaks repaired.
Dispose of old coolant at a recycling or hazardous-waste site.
Watch walks and roaming. Keep dogs on a lead near driveways and keep cats indoors where possible.
Choose propylene glycol products where practical.

For other seasonal risks, see our cold weather safety guide, the outdoor pet hazards guide and our post on Thanksgiving foods for dogs and cats.

Frequently Asked Questions

How quickly do antifreeze symptoms appear in dogs?

Early signs such as wobbliness, vomiting and extra thirst can appear from about 30 minutes to 12 hours after a dog swallows antifreeze. The dog may then seem to improve before kidney failure develops at around 36 to 72 hours, according to the Pet Poison Helpline and the Merck Veterinary Manual.

Can a dog survive antifreeze poisoning?

Yes, many dogs survive when the antidote is given early, before the kidneys are damaged. The Pet Poison Helpline advises treatment within about 8 to 12 hours for dogs. Once kidney failure has set in, the outlook is poor, so contact a vet as soon as you suspect exposure rather than waiting for signs.

Can a cat survive antifreeze poisoning?

Cats can survive, but they have a much shorter treatment window than dogs. The Pet Poison Helpline says treatment should begin within about 3 hours of ingestion to be effective in cats. If your cat may have licked or drunk antifreeze, go to a vet or emergency clinic immediately.

Should I make my dog or cat vomit after drinking antifreeze?

Do not try to make your pet vomit at home. It can be dangerous, especially in a drowsy or unsteady pet. A vet may decide to empty the stomach in the clinic if the timing is right. Call your vet or a pet poison helpline for instructions.

Can pets be poisoned by licking antifreeze off their fur or paws?

Yes. Pets can swallow coolant while grooming it off their coat or paws, and the Merck Veterinary Manual reports cats poisoned by skin products containing ethylene glycol. If your pet has walked through or been splashed with coolant, call a vet for advice right away.

Is propylene glycol antifreeze safe for pets?

Propylene glycol antifreeze is much less toxic than ethylene glycol and is a better choice for pet households, but it is not completely safe. The Merck Veterinary Manual notes it can still cause a similar, milder illness. Store it securely and call a vet if your pet swallows any.

When is antifreeze poisoning most common?

Cases tend to cluster in autumn, winter and early spring in cooler climates, according to the Merck Veterinary Manual, because that is when people add antifreeze or flush car cooling systems. Take extra care around driveways and garages during these months.

Do vets test for antifreeze poisoning?

Yes. Vets can use in-clinic blood test kits and laboratory tests to look for ethylene glycol, along with kidney blood values and urine checks. These tests work best within a limited time after ingestion, so vets may start treatment based on suspicion alone rather than wait for results.