If your dog or cat drank, licked, or walked through antifreeze or engine coolant, go to an emergency veterinarian now and call an animal poison control center on the way, even if your pet seems completely normal. Cats need the antidote within about 3 hours and dogs within about 8 to 12 hours. Use the antifreeze calculator to estimate the dose while someone else drives.
Enter weight, product, and amount. Every result is an emergency, with next steps.
What to do right now
- Move your pet away from the spill and keep other pets away. Wipe any antifreeze off fur and paws so it cannot be licked off.
- Note the time and grab the bottle, or take a photo of the label.
- Head to an emergency vet now. Call ASPCA Animal Poison Control or Pet Poison Helpline on the way so the hospital has a plan.
- Do not make your pet vomit unless a professional tells you to, and never if your pet is wobbly or sleepy.
- Do not give alcohol or any home remedy. The antidote is given in the hospital with blood tests and IV fluids.
- Do not wait for symptoms. A pet can look normal, or seem to recover, while the kidneys are being damaged.
How much antifreeze is toxic?
Most antifreeze is ethylene glycol. On its own it acts a bit like alcohol, but the liver turns it into acids and oxalate, which form sharp calcium oxalate crystals in the kidneys and cause sudden kidney failure (Merck Veterinary Manual).
Cats: the minimum lethal dose of undiluted ethylene glycol is 1.4 mL per kg of body weight. Pet Poison Helpline says as little as one teaspoon can be fatal to a cat.
Dogs: the minimum lethal dose is 4.4 to 6.6 mL per kg. Pet Poison Helpline says a tablespoon or two can be fatal, depending on the dog's size.
| Pet | Minimum lethal dose (undiluted) | About how much concentrate that is |
|---|---|---|
| 10 lb (4.5 kg) cat | 1.4 mL/kg | about 6 mL, a little over 1 teaspoon |
| 20 lb (9 kg) dog | 4.4 mL/kg | about 40 mL, under 3 tablespoons |
| 50 lb (23 kg) dog | 4.4 mL/kg | about 100 mL, under half a cup |
These are math examples from the Merck Veterinary Manual figures, not safe amounts. Kidney injury can happen below a lethal dose, 50/50 premixed coolant is still about half ethylene glycol, and it is almost impossible to know how much a pet lapped from a puddle. Treat any amount as an emergency.
Where pets find antifreeze, especially in winter
The Merck Veterinary Manual notes that most cases happen in fall, winter, and early spring, when people top off or flush car cooling systems. Pet Poison Helpline lists these common sources:
- Radiator coolant puddles and drips under cars, in garages, driveways, and parking lots
- Open or leaking jugs of antifreeze or coolant
- Toilets in cabins and vacation homes winterized with antifreeze
- Windshield de-icing products, brake fluid, and some motor oils. Pet Poison Helpline notes that some brake fluids contain diethylene glycol, which poisons in a similar way, and that windshield washer fluid may contain methanol, a different but also dangerous alcohol.
- Some imported snow globes, if they break and a pet licks the liquid
- Some paints, solvents, wood stains, and photo developing solutions
US antifreeze makers have added a bittering agent since 2012, but the Merck Veterinary Manual notes some animals will still drink it. Do not count on the bitter taste to protect your pet.
Symptoms and timeline
- 30 minutes to 12 hours: acting drunk, stumbling, vomiting, drooling, drinking and peeing a lot, sleepiness, and in some pets seizures
- About 12 to 24 hours: pets may seem to get better, but the heart and breathing rate rise and dehydration sets in while kidney damage continues
- Cats 12 to 24 hours, dogs 36 to 72 hours: kidney failure, with little or no urine, not eating, vomiting, mouth ulcers, severe lethargy, seizures, or coma
Timing is from the Merck Veterinary Manual and Pet Poison Helpline. The middle "false recovery" stage is why waiting is so dangerous: by the time a pet looks very sick, the antidote may no longer help.
Go straight to an emergency vet if
- Your pet drank, licked, or walked through any antifreeze or coolant
- Your pet is a cat, whatever the amount
- Your pet is acting drunk, wobbly, very thirsty, very sleepy, or is vomiting
- You found a leak, spill, or chewed bottle and cannot rule out drinking
- Your pet roams outdoors and suddenly seems drunk, even if you did not see it drink anything
What the vet will do
The vet will usually run a fast blood test for ethylene glycol along with blood gases and urine tests. Treatment often starts on suspicion alone if a test is not available, because time matters so much (Merck Veterinary Manual).
The antidote is fomepizole (also called 4-MP) or medical-grade ethanol given by IV. Both block the liver from turning ethylene glycol into its toxic breakdown products, so the body can pass it out in the urine. Pets also get IV fluids and treatment for acid levels, blood sugar, and calcium. The Merck Veterinary Manual protocols give the antidote over about 36 to 48 hours, so expect your pet to stay in the hospital for at least two days. Pet Poison Helpline notes that pets treated promptly and aggressively recover well, while once kidney failure sets in the outlook is poor and dialysis may be the only option.
How to prevent it
- Keep antifreeze, coolant, and windshield fluids tightly capped on a high shelf or in a closed cabinet.
- Clean up any spill or drip right away with paper towels or cat litter, then rinse the spot with water.
- Check under your car for green, orange, pink, or blue drips, and fix leaks.
- Keep pets out of the garage when you are working on a car, and do not let them drink from puddles on walks.
- If you winterize a cabin toilet or RV, close the bathroom door and tell guests with pets.
- Choose antifreeze made with propylene glycol when you can. ASPCA and Pet Poison Helpline both describe it as a safer alternative, though it is still not safe to drink.
For a room-by-room list you can print, see the pet poison-proofing checklist. Getting ready for the holidays? Read holiday hazards for pets and what to do if your pet ate rat or mouse poison, another common winter danger as mice move indoors.
Enter weight, product, and amount. Every result is an emergency, with next steps.
Frequently asked questions
How much antifreeze will kill a dog?
Pet Poison Helpline says a tablespoon or two of antifreeze can be fatal to a dog, depending on size. The Merck Veterinary Manual puts the minimum lethal dose of undiluted ethylene glycol at 4.4 to 6.6 mL per kg in dogs. Smaller amounts can still injure the kidneys, so any amount is an emergency.
How much antifreeze is toxic to a cat?
As little as one teaspoon can be fatal to a cat (Pet Poison Helpline). The minimum lethal dose of undiluted ethylene glycol in cats is 1.4 mL per kg (Merck Veterinary Manual), about a third of the dog dose.
How fast does antifreeze poisoning happen?
Signs that look like drunkenness can start within 30 minutes. Kidney failure follows within 12 to 24 hours in cats and 36 to 72 hours in dogs. The antidote must be started within about 3 hours for cats and 8 to 12 hours for dogs to work.
Can I treat antifreeze poisoning at home?
No. The antidotes, fomepizole or ethanol, are given by a veterinarian in the hospital, usually by IV with blood tests and fluids. Do not give your pet alcohol at home. Go to an emergency vet now.
Is pet-safe antifreeze really safe for pets?
Antifreeze made with propylene glycol has a much wider margin of safety than ethylene glycol (ASPCA), and Pet Poison Helpline recommends it as a safer choice. It is still not safe to drink: large amounts can cause severe sedation, wobbliness, and seizures, and cats are especially sensitive, so call poison control if it happens.