Pet Factsheets

Antifreeze (ethylene glycol) poisoning in your cat

Antifreeze is one of a number of products containing ethylene glycol which is very toxic to cats. If you suspect your cat has had access to anything containing ethylene glycol you must seek immediate veterinary attention. Some cats treated within 3 hours of drinking the poison will survive but if treatment is delayed almost all cats will die.

How might my cat access the poison?

Ethylene glycol (also known as ethanediol) is used in many products to stop them freezing. It is most commonly used in cars, especially in window washer fluid and radiators. Cats most commonly come across antifreeze where it has leaked into a puddle, been spilled when topping up fluid levels in a car or drained into a container in a garage.

Unfortunately the product is very palatable to cats and they will happily lap the fluid. This palatability gives rise to the other way that cats are exposed to ethylene glycol which is through malicious poisoning. Sadly there are some people who choose this method to rid themselves of what they perceive to be nuisance cats.

Most poisonings occur in the winter when antifreeze is widely used or in the spring when radiators are drained. However, antifreeze containing ethylene glycol may be lying around in sheds and garages all year round.

How much antifreeze does it take to make a cat ill?

Cats are very sensitive to the effects of ethylene glycol and even a small quantity is hazardous. Cats may even be poisoned by drinking rain water that collects in a vessel that previously contained antifreeze. So if you know your cat has had access to any such product you should take them to your vet immediately for treatment.

How would I know if my cat had been poisoned?

Within hours of ingestion of the poison cats may be depressed, and may drool saliva. They may then appear to recover but a day later become unwilling to eat. The main toxic effects of ethylene glycol occur in the kidneys but the signs of illness shown by affected cats are quite varied and vague. Once the effects of poisoning take hold cats will be depressed and vomit. As the condition progresses depression and breathing difficulties may worsen until a cat develops seizures and may fall into a coma.

How would my vet know if my cat has been poisoned?

Some antifreeze products contain a marker dye that is excreted in the urine. Your vet may be able to do a test on urine soon after your cat has drunk the poison to confirm that it was exposed. If you are concerned that your cat may have had access to antifreeze you should take them immediately to your vet and seek further advice.

Blood and urine tests will quickly start to show signs of kidney damage in poisoned cats and urgent treatment is needed. Ultrasound may show damage to the kidneys in later stages of disease.

Will my cat get better?

If your cat receives very early treatment from your vet there is a reasonable chance that they will survive. Those cats in which treatment is delayed beyond a few hours after poisoning are unlikely to survive. Unfortunately once typical signs of poisoning are present it may be too late for treatment to help.

Recovery, in those cats that do survive, occurs over 3-5 days.