Antifreeze (Ethylene Glycol) Toxicity in Pets

Estimated Reading Time 4 minutes
Antifreeze (Ethylene Glycol) Toxicity in Pets

Antifreeze or Ethylene Glycol (EG) used in car engines is highly toxic to dogs and cats. Ingestion is considered a medical emergency. Unfortunately, animals like the taste of antifreeze and will readily taste or drink it. Pets often discover antifreeze in the garage or parking area when it leaks from a car. It is made to stay in liquid form in freezing weather, increasing exposure to pets even if temperatures are low.

Are you concerned about your pet?

Book a video consultation with an experienced veterinarian within minutes.

  • Professional vet advice online
  • Low-cost video vet consultations
  • Open 24 hours a day, 365 days a year

What causes antifreeze poisoning in pets?

Antifreeze or ethylene glycol toxicity happens when animals drink and swallow it. This is followed by signs of depression, vomiting, unsteady or wobbly “drunk” appearance, and leads to acute kidney injury. Once swallowed, EG is rapidly absorbed into the bloodstream, causing a series of chemical reactions that produce kidney-damaging crystals.

Occasionally, people purposely make antifreeze available to pets with malicious intent.

Symptoms of Antifreeze Poisoning

1. Within 1-2 hours of drinking EG, the pet appears “drunk,” being unsteady or wobbly on their feet, falling, with nausea and vomiting.

2. Within a few hours, these signs improve, and owners notice their pet is getting better. The dog or cat then becomes quiet and depressed, with increased drinking and urination.

3. Within 24-72 hours after ingesting EG, the pet gets weaker, more depressed, has difficulty walking, not eating, difficulty breathing, and decreased or no urination. Body temperature drops and they may be painful in their stomach area.

4. In severe cases, pets begin to have seizures, body tremors or uncontrollable shaking, and rapid abnormal eye movements that occur within the first few hours after ingestion. Unfortunately, this is irreversible and fatal.

Diagnosis of Antifreeze Toxicity in Pets

If an owner sees their pet drinking EG or observes their pet near a puddle of fluorescent green liquid left by a car (in a garage or driveway for example) emergency veterinary care and treatment should begin immediately to prevent kidney injury often before test results come back positive.

Pets showing the signs listed above make EG toxicity very likely. Ethylene glycol toxicity is confirmed when pets test positive for EG through blood tests as well as other diagnostics which check kidney function, hydration status, and other markers.

Treatment Options for Pets with Antifreeze Poisoning

Ethylene glycol toxicity is a medical emergency because of how quickly it damages the kidneys, often irreversibly.

Pets are most likely to recover if treatment begins within 8-12 hours after exposure in dogs and less than 2 hours after exposure in cats.

Pets will need to be hospitalized and monitored closely under intensive care with medications to reverse the effects of EG in the body as well as intravenous fluids, monitor urine output, medications for nausea, and pain management.

Pet owners must often decide to euthanize their beloved pet when they show severe signs such as seizures, little to no urine output, and evidence of sudden kidney failure. In these cases, it is the humane and necessary decision to prevent further pain and suffering for their pet.

Are the effects of ethylene glycol toxicity permanent?

Pets may have permanent kidney damage from EG toxicity that cannot be reversed. Know that even with treatment, pets may need continued treatment as their kidneys recover and heal.

When caught early, within 8-12 hours of ingesting EG, dogs that receive appropriate intensive treatment have a fair to good outcome. Outcome is worse if a large amount of EG was ingested or for dogs with severe symptoms such as seizures and decreased or no urine production.

Cats are much more sensitive to EG toxicity, so the window for a good outcome is aggressive treatment within 3 hours of exposure. Only 1 small teaspoon (5 ml) of EG ingestion can be potentially deadly to an adult cat.

Preventing Antifreeze Toxicity in Pets

Pets must be supervised outdoors. Do not allow access to your garage or your neighbor’s garage, especially during freezing weather.

Keep cats strictly indoors.

Less toxic antifreeze products are available but can still cause problems. It’s important to monitor our vehicles for any leaks and clean up any spills regardless of which type of antifreeze product we use.

When to Contact a Veterinarian

If you suspect your pet has ingested antifreeze (ethylene glycol), contact your nearest Pet Emergency Hospital right away.

If your pet is showing any signs or symptoms listed above, acting “drunk”, even if or especially if symptoms improve, contact your nearest Pet Emergency Hospital right away.

Read more:

9 Ways to Keep Your Dog Safe this Winter

The Truth About Onion and Garlic Toxicity in Dogs

Can My Pet Eat Grapes and Raisins? The Truth About Grape Toxicity in Dogs and Cats

Need to speak with a veterinarian regarding antifreeze toxicity in dogs or another condition?

Click here to schedule a video consult to speak to one of our vets. You can also download the FirstVet app from the Apple App Store and Google Play Stores.

**If you know that your pet ingested antifreeze, take them to an emergency veterinary clinic right away!**

Are you concerned about your pet?

Book a video consultation with an experienced veterinarian within minutes.

Get started
  • Low-cost video vet consultations, 24 hours a day Low-cost video vet consultations, 24 hours a day
  • Experienced, licensed vets Experienced, licensed vets
  • Over 700,000 satisfied pet owners Over 700,000 satisfied pet owners
Low cost consultations, 24 hours a day.Low cost consultations, 24 hours a day.

With FirstVet, the vet clinic and pet shop are only one tap away. Get fast advice, trusted care and the right pet supplies – every day, all year round.


FirstVet Inc

900 3rd Ave 29th Floor


New York