Antifreeze (ethylene glycol) poisoning


  • EMERGENCY: Antifreeze (ethylene glycol) is highly toxic – contact your vet immediately if you think your pet has been exposed to it.
  • Antifreeze contains ethylene glycol, a very toxic chemical that causes severe damage to internal organs (even in very small amounts).
  • Sadly, antifreeze poisoning is often fatal unless it's treated extremely quickly.
  • It's important to take sensible precautions to prevent your pet coming into contact with antifreeze, especially throughout the colder months.

Why is antifreeze poisonous?

Antifreeze (ethylene glycol) is found in products such as car screen wash, brake and radiator fluid. If it’s is swallowed (even in small amounts), it’s extremely toxic and causes fatal damage to the kidneys and nervous system. Unfortunately, ethylene glycol is naturally sweet which, is why our pets are often tempted to drink it from leaky car radiators or driveway spillages.

Photo of screen wash being filled up in a car

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


Once swallowed, antifreeze quickly starts to take affect and cause the following symptoms

  • 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 immediately if you think your pet has been exposed to antifreeze. Never wait for symptoms to develop, the quicker they are treated, the better their chance of survival.

You know your pet best. If they don’t have the symptoms listed above but you think they may have been exposed, it’s always best to contact your vet.


It’s likely that your pet will need to stay in the veterinary hospital for several days, and treatment often includes:

  • Stomach emptying (only helps if caught very quickly)
  • Specific medicine to try to stop the effects of antifreeze
  • A fluid drip to flush out any toxins in the blood stream and try to prevent kidney failure
  • Washing any antifreeze off their skin and coat


Unfortunately, antifreeze poisoning is often fatal unless it’s treated very quickly, and it’s important to be aware that some pets improve initially but deteriorate again a few days after treatment finishes. If your pet is lucky enough to survive, it will take time for them to recover fully, and they may be at risk of kidney disease later in life.


  • Only ever buy antifreeze that contains a bittering agent to discourage pets from drinking it.
  • Be very careful not to spill or leave antifreeze products uncovered.
  • Keep an eye out for antifreeze spillages (especially around parked cars), and clear up any you find.
  • Avoid letting your dog roam near parked cars and exercise them away from any areas you think there could be spills.


Treating antifreeze poisoning can be very expensive because it often requires intensive treatment over a period of a few days. It’s important to speak openly to your vet about your finances, the cost of treatment, as well as what you think is right for your pet. There might be more than one treatment option, so if one doesn’t work for you and your pet, your vet may be able to offer another.

Consider insuring your pet as soon as you get them, before any signs of illness start. This will ensure you have all the support you need to care for them.

Published: August 2020

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