Antifreeze (ethylene glycol)
ToxicThe minimum lethal dose of ethylene glycol in dogs is 4.4-6.6 mL/kg, about two tablespoons for an 11 lb dog. Dogs look better around 12 hours, then go into kidney failure at 36-72 hours. Go now.
This food guide has not been reviewed by a veterinarian. It summarises general information from sources and should not be used to decide whether a food is suitable for an individual dog or to assess an emergency.
Check before feeding
Do not offer as a treat
There is no recommended treat portion for this hazardous item. If swallowed, contact a vet with the amount, time and product details. Do not induce vomiting yourself.
Signs and health concerns
This list includes both observable signs and conditions identified through examination or testing. It cannot establish the cause or whether an exposure is safe.
- Vomiting
- Poor coordination or balance
- Increased thirst
- Increased urine volume
- Lethargy
- Seizures
- Raised nitrogen waste in blood
- Reduced urine output
- Dehydration
- No urine production
- Rapid breathing
- Collapse
More about this food
Antifreeze poisoning is dangerous for two reasons: it tastes sweet, so dogs drink it willingly, and there is a stretch where the dog looks like he is recovering.
Start with the amount. The Merck Veterinary Manual gives a minimum lethal dose of 4.4-6.6 mL/kg of ethylene glycol in dogs. For an 11 lb (5 kg) dog that is 22-33 mL, roughly two tablespoons. A few laps at a bright green puddle in a parking garage or on a driveway gets there.
The timeline is what traps owners. Stage 1 runs from 30 minutes to 12 hours: the dog looks drunk, stumbles, vomits, and drinks and urinates more than usual. Then, around 12 hours, there is an apparent recovery. That false window is where most fatal decisions get made. Stage 2 arrives at 36-72 hours as acute kidney failure, with painful enlarged kidneys, falling urine output, continued vomiting and neurological decline. Calcium oxalate crystalluria can appear as early as 6 hours in dogs.
There is an antidote, which is the one piece of good news here. Fomepizole (4-MP) or ethanol blocks the liver from converting ethylene glycol into the metabolites that destroy the kidneys. But Merck is explicit that prognosis varies inversely with the time between ingestion and the start of treatment, and that once a dog is azotemic or in oliguric kidney failure the prognosis is guarded to poor. Every hour spent watching costs treatment options.
Grab the container or photograph the label, note the time and your dog's weight, and drive to your veterinarian or an emergency animal hospital now. You can call the ASPCA Animal Poison Control Center at (888) 426-4435 on the way. Do not induce vomiting at home. Then prevent the next one: store antifreeze and windshield washer fluid capped and out of reach, clean up spills immediately, and consider propylene glycol-based coolant, which is a different compound with its own separate Merck monograph.
Frequently asked questions
- I am not certain he drank any. Should I wait and see?
- No. Two tablespoons is a lethal dose for an 11 lb dog and the antidote works best before signs appear. Call your veterinarian or the APCC at (888) 426-4435 now and let them decide, even if you are unsure.
- He was wobbly earlier and now he seems fine. Did we get lucky?
- No. The apparent recovery around 12 hours is a known feature of ethylene glycol poisoning, and kidney failure follows at 36-72 hours. Looking normal right now is the best time for treatment to work, not a reason to skip it.
- What about windshield washer fluid?
- Different chemical. Washer fluid is usually methanol-based, which causes its own alcohol toxicosis. Either way, bring the bottle so the clinic can read the active ingredient rather than guess.