Antifreeze (ethylene glycol) poisoning

Cat and dog on white background


Contact your vet straight away if you think your pet has come into contact with antifreeze.

Antifreeze (ethylene glycol) is a common poison in dogs and cats. It’s a very toxic substance – even a small amount can do a lot of damage to several vital organs.

Unfortunately, anti-freeze poisoning is difficult to treat and is often fatal. Preventing your pets coming into contact with it isn’t easy but there are a few sensible precautions you can take.

Why is antifreeze poisonous?

Antifreeze is a common ingredient used in products such as vehicle screen wash, brake fluid and radiator fluid. It’s extremely toxic to cats and dogs.

Even a small amount of antifreeze can cause kidney failure and serious damage to the nervous system. Sadly, due to the severe effects it has on the body, antifreeze poisoning is often fatal.

Unfortunately, a lot of anti-freeze products taste sweet which is why our pets are often tempted to drink them. Leaky car radiators and antifreeze fluid spilt on roads and driveways pose a big danger to our pets.

Antifreeze is more dangerous for cats than dogs as it takes a smaller amount to cause a problem.

Photo of screen wash being filled up in a car

Antifreeze is found in products such as screen wash, brake and radiator fluid.


Antifreeze is absorbed into the system very quickly. It attacks the nerves, heart, lungs and the kidneys.

Common symptoms include:

  • Twitchy muscles
  • Twitchy eyes
  • Low energy (lethargy)
  • Vomiting
  • Drinking more than usual
  • Unsteadiness
  • Seizures (fits)
  • Fast, panty breathing
  • Collapse.
Photo of cat licking antifreeze spill

Antifreeze spills and leaky engines are a big risk to our pets.

When to contact your vet

Contact your vet straight away if you think your pet has come into contact with antifreeze.

You know your pet best. If they don’t have the symptoms listed above but you are still concerned it’s always best to contact your vet.


Antifreeze poisoning is very dangerous, the sooner your pet gets treatment the better their chance of surviving.

Your pet will need to be admitted to the veterinary hospital and treatment may include:

  • Stomach emptying (only helps in the very early stages of poisoning)
  • Specific medicine to stop the effects of antifreeze
  • A drip – to give lifesaving fluids.


Unfortunately, antifreeze poisoning is often fatal. Your pet may need to spend several days in the veterinary hospital. If they are lucky enough to survive, your vet will send them home once they’re over the worst of the poisoning. Sadly, some pets will improve and then deteriorate again after a few days. It will take time for your pet to fully recover and they may be at risk of developing chronic kidney disease later in life.


It’s impossible to stop free-roaming cats finding antifreeze spills when they are out and about but you can make sure to clean up any anti-freeze spillages in your own area immediately. Avoid letting your dog roam near parked cars and exercise them away from any areas you think there could be spills.

Fortunately, more modern, antifreeze products tend to be safer and don’t contain ethylene glycol. Some companies have started adding a bitter taste to their antifreeze to discourage pets from drinking it.

Published: December 2018

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Written by vets and vet nurses. This advice is for UK pets only.

Illustrations by Samantha Elmhurst