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Veterinary Teaching Hospital

Antifreeze poisoning in dogs and cats

Siamese cat drinking from a puddle on a driveway.

Antifreeze is extremely toxic to animals and can cause fatal kidney failure. Unfortunately, dogs and cats find the liquid quite tasty and will eagerly drink it up when given the chance.

What should I do if my pet ingests antifreeze?

Contact a veterinarian immediately if you see your pet drinking antifreeze or suspect it had access to antifreeze. Very small amounts of antifreeze can be fatal.

For example, a cat can ingest a fatal amount of antifreeze by simply licking its paws after walking through a puddle of the chemical. Five tablespoons are enough to kill a medium-sized dog.

If you suspect your animal has ingested antifreeze, staff at the WSU Veterinary Teaching Hospital are available for emergencies 24/7 and can be reached at 509-335-0711.

What are the signs of antifreeze poisoning in dogs and cats?

Signs of antifreeze poisoning depend upon the time after ingestion. In the first hours after ingestion, the pet may be depressed, stagger when moving, and have seizures. They may drink lots of water, urinate large amounts, and vomit.

The pet may appear to feel better only to get much worse a day or two later as its kidneys fail. Signs of kidney failure include depression and vomiting. The amount of urine they pass will often decrease to a very small amount.

How is antifreeze poisoning in pets diagnosed?

The diagnosis of antifreeze poisoning is made by blood and urine tests, although some of these tests will show negatives by the time kidney failure develops. Antifreeze poisoning should be considered in any free-roaming dog or cat with consistent signs.

How is antifreeze poisoning in pets treated?

Treatment for antifreeze poisoning needs to be started as soon after ingestion as possible to be effective. The earlier treatment is started, the greater the chance of survival. Once kidney failure develops, most animals will die.

If the pet is seen within a few hours of ingesting antifreeze, vomiting is induced to remove any antifreeze still in the stomach, and charcoal is placed in the stomach to bind antifreeze in the intestine. Antifreeze itself is not very toxic but it is broken down by the liver to other components that cause the damage. If the pet is presented to a veterinarian soon after drinking antifreeze, a drug is given that impairs the liver from converting antifreeze to these toxic products, allowing the unconverted antifreeze to pass in the urine. These drugs are useful only when given early and are not effective after the pet is showing signs of kidney damage.

Animals that present to a veterinarian in kidney failure due to antifreeze poisoning can occasionally be saved with aggressive treatment. Some specialty veterinary practices offer dialysis that can be used to eliminate waste products not being removed by the diseased kidneys to keep the pet alive and give the kidneys a chance to repair. Whether the kidneys will repair themselves or not depends on how severely they are injured. Unfortunately, kidney damage caused by antifreeze is usually severe and irreversible. Kidney transplantation has been performed in dogs and cats.

How can I prevent antifreeze poisoning?

There are several steps you can take to protect your pets from being poisoned by antifreeze.

  • Keep new and used antifreeze in a sealed, leak-proof container
  • Take used antifreeze to a service station for disposal – don’t pour it on the ground
  • Check driveways for puddles of antifreeze that may have leaked from the car
  • Consider the use of alternative antifreeze products that are less toxic to pets
  • If antifreeze is placed in toilets make sure the lid is down and the door to the room is closed

This information is not meant to be a substitute for veterinary care. Always follow the instructions provided by your veterinarian. Washington State University assumes no liability for injury to you or your pet incurred by following these descriptions or proc