Is Antifreeze Toxic to Dogs and Cats?
Antifreeze containing ethylene glycol is one of the deadliest toxins for dogs and cats. It has a sweet taste that attracts pets, and as little as one tablespoon can kill a cat or a small dog.
What Makes Antifreeze (Ethylene Glycol) Dangerous to Pets?
Antifreeze containing ethylene glycol is one of the deadliest toxins for dogs and cats. It has a sweet taste that attracts pets, and as little as one tablespoon can kill a cat or a small dog. Ethylene glycol is metabolized into toxic compounds that cause severe kidney damage. The treatment window is extremely narrow — 8-12 hours for dogs and only 3 hours for cats. Antifreeze poisoning is most common in fall and winter when vehicles are serviced.
Toxic Agent
Ethylene glycol (metabolized to glycolic acid and oxalic acid)
Common Sources
- •Automotive antifreeze and coolant (most common source)
- •Puddles of leaked coolant in driveways and garages
- •Windshield de-icing fluids
- •Hydraulic brake fluid (some formulations)
- •Snow globes (contain small amounts of ethylene glycol)
Symptoms of Antifreeze (Ethylene Glycol) Poisoning in Dogs & Cats
Mild Symptoms
- ▸Drunkard-like staggering within 30 minutes to 1 hour
- ▸Nausea and vomiting
- ▸Excessive thirst and urination
Moderate Symptoms
- ▸Apparent improvement after 12-24 hours (deceptive "better" phase)
- ▸Rapid heart rate and breathing
- ▸Dehydration
Severe / Emergency
- ▸Kidney failure (24-72 hours) with no urine output
- ▸Seizures and severe depression
- ▸Coma and death
What to Do If Your Pet Is Exposed to Antifreeze (Ethylene Glycol)
- 1
This is a life-or-death emergency. Rush to a vet immediately.
- 2
Note the approximate amount licked or ingested and the time.
- 3
Do NOT wait for symptoms or try to treat at home.
- 4
The antidote (fomepizole or ethanol) must be given within hours.
- 5
Use VetGeni's free toxin checker only while en route to the vet.
When to See the Vet
Immediately. The treatment window is 8-12 hours for dogs and only 3 hours for cats. Once kidney failure develops, the damage is irreversible. Even suspected exposure warrants emergency care.
Prognosis
Good if fomepizole (Antizol-Vet) is administered within the treatment window. Once kidney failure develops (Stage 3, after 24-72 hours), prognosis is grave and often fatal.
Check Antifreeze (Ethylene Glycol) Toxicity for Your Pet
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- Substance and estimated amount
- Pet weight and species
- Time since ingestion
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Frequently Asked Questions
- Why are pets attracted to antifreeze?
- Ethylene glycol has a sweet taste that dogs and cats find appealing. Pets may lick puddles of leaked coolant, drink from containers, or walk through spills and then groom their paws. Some newer antifreeze products include bittering agents (denatonium benzoate) to deter ingestion.
- How much antifreeze is lethal to a dog or cat?
- The lethal dose for dogs is approximately 4.4 mL/kg (about 2 tablespoons for a 10 lb dog). For cats, the lethal dose is only 1.4 mL/kg (about 1 teaspoon for a 10 lb cat). These are extremely small quantities.
- Is there a pet-safe antifreeze?
- Propylene glycol-based antifreeze is significantly less toxic than ethylene glycol and is considered a safer alternative for pet households. While not completely non-toxic, it has a much wider margin of safety. Look for products labeled "pet-safe" or "low-toxicity."
Related Pet Toxins
Emergency? Call Poison Control
If your pet is showing severe symptoms, call immediately:
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Reviewed by Dr. Christopher Tiller, DVM — Emergency Veterinarian & VetGeni Founder. This information is for educational purposes and does not replace professional veterinary care. Always consult a veterinarian for specific medical advice.