The Dangers of Antifreeze

Many commercial Antifreeze mixes still contain Ethylene Glycol. This is one of the most dangerous household poisons and its ingestion is frequently fatal in both cats and dogs...

Ethylene Glycol is very sweet which means sadly that our pets are much more likely to have a fatal exposure; in fact, it has the highest fatality rate of all veterinary poisons.

The poisoning has a number of stages.

1) Soon after ingesting the poison Ethylene glycol starts to alter brain function. Its effects are similar to alcohol, causing an altered mental state often with initial excitement followed by depression, weakness, and stupor or a coma. There usually is wobbliness and difficulty in balancing, followed by a loss of reflexes. Nausea and vomiting follow with increased urination, resulting in dehydration. Pets may increase their drinking to try and compensate, but once they become comatose, obviously they cannot then maintain their fluid intake.

2) Most dogs will apparently recover from this “drunkenness”, and often seem virtually normal by about 12 hours after ingestion.  Cats, on the other hand, stay sleepy, depressed or even unconscious, and usually, do not show this “recovery”.

3) Late toxicity - kidney failure: The real concerns with ethylene glycol is that it is broken down in the body into glycolaldehyde, which is extremely toxic to kidney tissues. Initially, the amount of urine production increases, but then starts to decrease sharply. This decreased urination (“oliguria”) is often the first sign that serious, and usually permanent, kidney damage has actually occurred. In dogs, it usually starts about 36-72 hours after ingestion. Cats are more rapidly affected, with kidney symptoms starting at about 12-24 hours after poisoning.  Symptoms of Kidney damage are: Nausea and vomiting; Dehydration; A strange, metallic smell on the breath; collapse, seizures, coma and ultimately death. As the kidneys fail, they are unable to remove waste products and toxins from the bloodstream, resulting in a toxic, “uraemic syndrome”. The less urine the patient is able to make, the worse the prognosis for the case. Cats and puppies usually suffer worse than adult dogs, but any animal that becomes anuric, with no urine production, is very unlikely to recover, even with treatment.

Unlike most poisons, it isn’t usually possible to get dogs and cats to vomit up the antifreeze, even if you’ve seen them drinking it and rushed them to the Vet straight away. This is because the toxin is very rapidly absorbed through the stomach wall.

The main aim of treatment, therefore, is to then slow down the conversion of ethylene glycol into the more toxic glycolaldehyde. There are drugs available to achieve this, but both require intensive Veterinary care and hospitalisation for several days and treatment must be started as soon as possible.  

Sadly, once kidney failure starts the majority of affected dogs and virtually all affected cats will die. In animals that do survive the kidney failure stage, most will then have on-going, lifelong kidney problems.

Please do keep all Antifreeze products well out of reach of your pets and mop up carefully after any spillages.  Also be aware that some "path salt" products may also contain Antifreeze.

If you think your pet may have ingested anything containing antifreeze contact the practice for assistance immediately.