Anti-freeze poisoning in cats

Grey cat on scales

We have seen a few anti-freeze poisoning cases here at Farthings over the last few months. Here is some information about what to look out for and what to do if you think your cat may have been affected.

Anti-freeze contains ethylene glycol, an organic molecule with a sweet taste that is colourless and odourless. Cats are particularly partial to the taste of anti-freeze and will frequently ingest highly toxic amounts if allowed. They can also pick it up on their feet and swallow it while grooming.


Ethylene glycol causes acute kidney failure; symptoms include vomiting, wobbliness or a ‘drunken’ appearance, depression and anorexia.

What to do next

If your cat is displaying these symptoms it is important to get them into your vet as soon as possible because treatment needs to be started immediately to be most effective. We will take a blood sample to look for signs of acute kidney damage. The diagnosis is confirmed by finding specific crystals called calcium oxalate monohydrate in the urine.

If you have seen your cat ingest the anti-freeze it may be possible for us to make him sick before the toxic effects have time to start, but this is rare. More often we are presented with cats that have been poisoned some hours ago and are already in kidney failure.

Other treatments include the use of ethanol intravenously (vodka can be used!), as this inhibits the enzyme used to metabolise the anti-freeze into its toxic form.  The mainstay of treatment is aggressive intravenous fluid therapy to restore blood volume and for diuresis of the kidneys. Cats also need to be monitored for electrolyte disturbances which can cause heart arrhythmias, and also acidosis, which may need to be treated separately.

Act quickly

If you think your cat is displaying any of these signs, give us a call straight away and we will arrange for him to be seen as soon as possible. Remember we are available 24-hours on the normal phone number.