Antifreeze Poisoning in Cats

Symptoms and Treatments of Antifreeze Toxins in Cats

Antifreeze poisoning is one of the most common forms of poisoning in small animals because it is commonly found in households. Antifreeze poisoning typically happens when antifreeze drips from a car’s radiator, where it is then picked off the ground and ingested by an animal. Ethylene glycol is also found in engine coolant and hydraulic brake fluids.

Your cat may also come into contact with antifreeze that has been added to a toilet bowl.

This occurs in homes where the residents will use antifreeze during the cold months to "winterize" their pipes. Even if you do not take this action in your own home, it is something to be aware of when visiting other homes, or when vacationing at a winter residence.

How Ethylene Glycol Is Lethal

It is the toxin, ethylene glycol, that makes antifreeze lethal. Ethylene glycol has a sweet taste to it, causing animals to consume the liquid in quantity before the aftertaste becomes apparent and causes it to stop. By then, it is too late, as it does not take a significant amount of ethylene glycol to cause fatal damage to the system. Less than three ounces (88 ml) of antifreeze is sufficient to poison an animal, affecting the brain, liver and kidneys.

Symptoms of Antifreeze Poisoning in Cats

  • Rapid heart beat
  • Depression
  • Weakness
  • Seizures/convulsions/shaking tremors
  • Fainting, coma

Diagnosis and Treatment

If you witnessed your cat ingesting antifreeze, or suspect it based on symptoms and access to the substance, immediately encourage your pet to vomit.

For immediate first aid, if you are positive that your pet has ingested this toxic substance, try to induce vomiting with a simple hydrogen peroxide solution of one teaspoon per five pounds of body weight, with no more than three teaspoons given at once.

This method should only be used if the toxin has been ingested in the previous two hours and should only be given three times, spaced apart at ten-minute intervals. If your pet has not vomited after the third dose, do not use it or anything further to try to induce vomiting.

Call Your Veterinarian

You may want to call your veterinarian before trying to induce vomiting since it can be dangerous to do so with some toxins. Some poisons will do more harm coming back through the esophagus than they did going down. Do not use anything stronger than hydrogen peroxide without your veterinarian's consent and do not induce vomiting unless you are absolutely sure of what your cat has ingested. If your cat has already vomited, do not try to force more vomiting.

About Your Cat Post Antifreeze Consumption

Do not induce vomiting if your cat is unconscious, is having trouble breathing or is exhibiting signs of serious distress or shock. Whether your cat vomits or not, after the initial care, you must rush it to a veterinary facility immediately. Your veterinarian will be able to safely administer antidotes to the poison, such as activated charcoal, to prevent further absorption of the toxin and is able to treat antifreeze poisoning with 4-methylpyrazole if given shortly after consumption.

Your cat may need to be held in intensive care for a short time to observe for and prevent kidney failure.

Cats that have consumed antifreeze in very small quantities may survive but will develop kidney failure within days of ingestion. Death due to kidney damage is common among animals that have been poisoned by antifreeze.

Prevention of Antifreeze Poisoning

  1. Keep antifreeze containers tightly closed and stored out of the reach of pets.
  2. Take care not to spill antifreeze. If it does spill, ensure that it is immediately and thoroughly cleaned up.
  3. Dispose of used antifreeze containers properly.
  4. Check the radiator of your car regularly and repair leaks immediately.
  5. Do not allow your cat to wander unattended where there is access to antifreeze, such as around roads, gutters, garages and driveways.
  6. Use new antifreeze products available, such as those that use the safer propylene glycol as an agent, which the American Food and Drug Administration has labeled as non-toxic. Antifreeze with this ingredient helps prevent accidental poisonings with pets.