What Is Ethylene Glycol Poisoning?
Ethylene glycol is the main ingredient in most car antifreeze and engine coolant. It tastes sweet, so dogs and cats will lap up spills or leaks from a car. Once swallowed, the body breaks it down into toxic compounds that damage the brain and then cause severe acute kidney failure. It is one of the most dangerous household and garage poisons for pets.
Very small amounts can be deadly. A teaspoon or so can be fatal for a cat, and a few tablespoons can be fatal for a medium-size dog. Ethylene glycol is also found in some brake fluids, de-icers, paints, and novelty snow globes.
Why it matters
The antidote only works if it is given within hours of drinking antifreeze. By the time kidney failure is obvious, it is often too late to save the pet.
Signs and Stages
- Stage 1 (30 minutes to about 12 hours): acting drunk, wobbling, vomiting, drooling, and heavy drinking and urinating.
- Stage 2 (about 12 to 24 hours): the pet may seem to recover, which falsely reassures owners while damage continues.
- Stage 3 (about 12 to 24 hours in cats, 36 to 72 hours in dogs): kidney failure with vomiting, not eating, lethargy, little or no urine, seizures, or coma.
See our broader guide to dog poisoning symptoms for other common toxins.
Diagnosis
If you saw or suspect antifreeze exposure, tell your vet right away, as history is the biggest clue. Vets can run an in-clinic ethylene glycol test, bloodwork, and a urine test that may show calcium oxalate crystals. Kidney values rise later, so normal early results do not rule out poisoning. Signs of kidney failure or chronic kidney disease in cats have other causes too, which is why a quick exposure history matters.
Treatment and Outlook
- Antidote: fomepizole (also called 4-MP) or, in some cases, medical-grade ethanol, which blocks the body from turning ethylene glycol into its toxic products.
- Timing: in dogs it works best within about 8 to 12 hours; in cats the window is much shorter, around 3 hours.
- IV fluids and monitoring: to support the kidneys and correct blood chemistry.
- Dialysis: at referral hospitals for pets that already have kidney damage.
Pets treated early often recover fully. Once kidney failure sets in, the outlook is poor even with intensive care.
Practical Tips for US Pet Owners
- Choose antifreeze labeled propylene glycol, which is much less toxic, and store all coolant in sealed containers up high.
- Clean garage and driveway spills immediately and check your car for leaks.
- Call ASPCA Animal Poison Control at (888) 426-4435 or Pet Poison Helpline at (855) 764-7661 if you suspect exposure (fees may apply).
- Use our puppy-proofing and kitten-proofing checklists, plus cat first aid basics.
- Know your nearest emergency practice through veterinary clinic listings.
When to see a vet
Treat any suspected antifreeze drinking as an emergency, even if your pet seems fine. Go to a vet immediately. Do not wait for symptoms.
Key Takeaways
- Antifreeze tastes sweet and is deadly in small amounts to dogs and cats.
- The antidote must be given within hours, especially in cats.
- Propylene glycol antifreeze and quick spill cleanup prevent most cases.
FAQ
Should I make my pet vomit after drinking antifreeze?
Call your vet or a poison hotline first. Only induce vomiting if a professional tells you to.
Is “pet-safe” antifreeze completely safe?
Propylene glycol antifreeze is far less toxic, but it is still not food. Keep any coolant away from pets.
My pet seems normal after drinking antifreeze. Is it okay?
No. Pets can look normal during the middle stage while kidney damage is starting. Get treatment right away.