Why?

Antifreeze typically contains ethylene glycol — a sweet-tasting compound that dogs readily lap up from garage floors, puddles, or spills. The sweet taste belies extreme toxicity: ethylene glycol itself is not the primary toxin, but its metabolites are. After absorption, ethylene glycol is metabolized by liver enzymes into glycolic acid and oxalic acid, which form calcium oxalate crystals that destroy kidney tubular cells.

The insidious danger: dogs appear drunk in the first 1–4 hours (ethylene glycol's direct CNS effects), then apparently recover, while crystal deposition is destroying the kidneys. By the time kidney failure symptoms appear (24–72 hours), irreversible damage has already occurred — and the treatment window has often closed.

Propylene glycol antifreeze is less toxic but still causes serious CNS effects in dogs. Any antifreeze ingestion should be treated as immediately life-threatening.

How much is dangerous?

As little as 4.4ml per kg is lethal for dogs. One teaspoon can kill a 10-lb dog. The lethal dose is alarmingly small.

What are the symptoms?

ONSET:Initial symptoms: 30 minutes. Apparent recovery: 6–12 hours. Fatal kidney failure: 24–72 hours.
  • first 30 min–12 hours: vomiting, appearing "drunk," excessive thirst and urination
  • 12–24 hours: apparent recovery (deceptive)
  • 24–72 hours: vomiting, lethargy, seizures, acute kidney failure, complete cessation of urination

What should I do?

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This is a time-critical emergency — the antidote (4-MP / fomepizole) must be given within 8–12 hours to be effective. Do not wait for the "apparent recovery" phase. Call your vet or emergency clinic immediately.

Frequently asked questions.

My dog licked antifreeze off the garage floor — what do I do?

Emergency vet NOW — even if only a small amount was consumed. The window for effective antidote treatment closes within hours.

Is "pet-safe" antifreeze actually safe?

Propylene glycol antifreeze is less acutely toxic than ethylene glycol, but still causes neurological symptoms and is not safe. Treat any antifreeze ingestion as an emergency.

Disclaimer: This information is for educational purposes only and does not constitute veterinary advice. Every dog is different. Always consult your veterinarian before making changes to your dog's diet or in the event of a potential poisoning emergency.