About 30 minutes ago, I walked into our
Ask
About 30 minutes ago, I walked into our garage and found our 4kg adult cat licking a small green puddle of spilled automotive radiator coolant / antifreeze from under our car. I immediately picked him up and wiped his mouth and paws with a damp paper towel. Right now he seems alert and normal, maybe a little drooly.
My roommate told me: "Antifreeze tastes sweet so animals lick it, but it was just a tiny lick from the floor. Give him a bowl of whole milk or bread to coat his stomach and let us watch him for a few hours before spending money at the ER vet."
However, I read that ethylene glycol in antifreeze is deadly toxic to cats even in minuscule amounts.
Could you provide urgent veterinary emergency guidance:
1. **Lethal Toxicity in Cats**: Why is ethylene glycol considered an extreme, time-sensitive feline emergency with a minimum lethal dose as low as 1.4 mL/kg (less than a single teaspoon for a 4kg cat), and why are cats far more sensitive than dogs?
2. **The 3-Phase Progression**: What are the 3 clinical stages of ethylene glycol toxicosis (Phase 1: 30m–12h "drunken" ataxia/vomiting; Phase 2: 12–24h cardiopulmonary signs; Phase 3: 12–24h fatal acute anuric renal failure from calcium oxalate crystal deposition)?
3. **The Urgent Antidote Window & Immediate Actions**: Why must fomepizole (4-MP) or medical-grade ethanol infusion be initiated within 1–3 hours before toxic metabolites destroy the kidneys, and why must we NEVER give milk, bread, or induce home vomiting with hydrogen peroxide (which causes severe hemorrhagic gastritis in cats)?
Answer
This is a true emergency. Before drafting a single sentence I need the species emergency card, the antifreeze toxin card, the cat's record if any, and the nearest open emergency vets.
**Go to an emergency veterinarian now, then call on the way.** For a 4 kg cat, even a small lick of automotive antifreeze puts him inside the lethal-exposure band. This is the most time-sensitive feline toxin there is — the only chance to block the kidney damage is in the first few hours, and your cat is inside that window right now.
**Call first (on the way to the car):**
- **Animal Poisons Helpline (Australia): 1300 869 738 — 24/7, paid triage consult.** They will tell you which clinic near you is open right now and ready to start the antidote. This number is from this turn's poison-line search; it is for animals, not people.
**Take with you:**
- The antifreeze bottle or a clear photo of the label (concentration + whether it contains a bitter additive).
- His weight (4 kg) and the time you found him (about 30 minutes ago).
- Any antifreeze still on his fur or paws.
| Do now | Do not |
| --- | --- |
| Drive to the nearest open emergency vet | "Wait a few hours and see how he does" |
| Call the helpline and the clinic ahead | Give milk, bread, or any home food/remedy |
| Keep him calm in a carrier | Make him vomit at home |
| Keep the bottle/photo for the vet | Try to rinse his mouth again at home |
---
### Why your roommate's advice is the wrong call here
- **"Watch and see" loses the antidote window.** The antidotes that can block kidney failure (fomepizole / 4-MP, or medical-grade ethanol given IV) only work if they are started within roughly the first few hours after the lick. After that the toxic metabolites are already turning into calcium oxalate crystals inside the kidneys, and the only thing left is supportive care, often too late. "Acting normal for a few hours" is exactly what this toxin looks like before the kidneys shut down.
- **Milk and bread do not bind or neutralize ethylene glycol.** They do not delay absorption enough to matter; they just postpone real treatment.
- **Hydrogen peroxide to make a cat vomit is unsafe.** In cats it commonly causes severe hemorrhagic gastritis and can be fatal on its own. Cats should never be made to vomit at home for any reason — the vet decides what to do, and often the better move is to secure the airway, draw blood, and start the antidote straight away.
---
### Why ethylene glycol is uniquely deadly in cats
From the toxicology card opened this turn (MSD/Merck, minimum lethal amount of the undiluted product):
- **Lethal dose in cats ≈ 1.4 mL/kg.** For your 4 kg cat that is roughly 5–6 mL of neat antifreeze — about a teaspoon. A cat lapping a puddle on a garage floor easily takes that much. **Dogs need 4.4–6.6 mL/kg** to reach the same lethal threshold — roughly three to four times more tolerant. Cats are the most sensitive companion species because their liver enzymes convert ethylene glycol into its deadly metabolites (glycolic and oxalic acid) faster than dogs, and they clear the parent compound more slowly; even a small dose produces a high, sustained level of the kidney-destroying metabolite.
---
### What the next day looks like — and why the clock matters
This pattern is from the card and the standard veterinary text behind it:
- **Phase 1 — ~30 minutes to 12 hours.** Early nervous-system and gut signs: the cat seems "drunk," wobbly, drooly, may vomit, may drink more. **Your cat's mild drooling fits here. This is the only window where the antidote still works.**
- **Phase 2 — roughly 12–24 hours.** As the acids build up, breathing rate and heart rhythm can change.
- **Phase 3 — ~12–24 hours onward.** Acute kidney failure as calcium oxalate crystals form inside the renal tubules. By this point damage is largely irreversible and many cats do not survive even with dialysis-level care.
The card is explicit: *"This is a time-sensitive emergency; leave immediately and contact emergency care by telephone at the same time"* and *"do not attempt home detoxification."*
---
### Vets near you (this turn's map search — call ahead, hours change)
- Pyrmont Vet — 1 Scott Street, Pyrmont NSW 2009 — (02) 8203 0355
- Potts Point Veterinary Hospital — 41b Elizabeth Bay Road, Elizabeth Bay NSW 2011 — +61 2 8097 0060
- Glebe Veterinary Hospital — 113 Glebe Point Road, Glebe NSW 2037 — +61 2 9660 1771
- Paddington Cat Hospital — 210 Oxford Street, Paddington NSW 2021 — (02) 9380 6111
- Vet HQ Double Bay — 389 New South Head Road, Double Bay NSW 2028 — +61 2 9326 1255
(Map data © OpenStreetMap via Geoapify; some hours from Google Maps. A listing is not a promise they are open or see emergencies right now — phone before you set off. The Animal Poisons Helpline can tell you which one is open and equipped to start the antidote right now.)
---
We do not diagnose or work out doses — only the vet on the phone does. Please leave now and call the helpline on the way; you are still inside the antidote window.