If you think your cat drank antifreeze, you'll want to act fast.
cat laying under a car; what to do if your cat drinks antifreeze
Credit: Tevarak / Getty

Antifreeze poisoning in cats is a serious issue, and it can happen easier than you think. 

You accidentally lock Kitty in the garage, and she doesn't have access to her water bowl. The spilled antifreeze from a poorly placed bottle or a broken radiator is the only liquid around for the parched cat to drink. Or perhaps spilled antifreeze simply invites the curiosity of a cat, who takes a taste of the sweet-smelling stuff. In this case, Ahna Brutlag, a veterinarian who works with the Pet Poison Helpline to answer questions about toxic substances, says that curiosity can quite literally kill the cat.

How Dangerous is Antifreeze to Pets?

Antifreeze, made up of ethylene glycol, is incredibly dangerous if your cat (or dog, or children) ingest it. In fact, it only takes as little as one eighth of a teaspoon of antifreeze per pound of body weight in a cat to result in fatality.

Brutlag says that while inquiries from vets and pet owners about antifreeze poisoning is not quite at the top of their list of questions, she does receive a fair number of them. "Certainly cat owners call right away if they see a spilled container of antifreeze around their cat," she says. "Other times they see the signs [of] antifreeze poisoning and they're checking."

But it's better to be safe than sorry, since antifreeze poisoning is a dire situation, since the primary ingredient will start harming your cat's kidneys in the first few hours after ingestion.

Why Do Cats Drink Antifreeze?

"It's kind of conventional wisdom that it's appetizing to cats [because it's sweet]," Brutlag says. "But cats don't have sweet taste receptors."

In one study, cats seemed neither attracted to nor grossed out by sweetness. Cats who drink antifreeze may be curious, may be desperately thirsty, or may find something they like about the color, smell, or taste of the substance.

"Antifreeze is dangerous to humans and dogs, but cats are more sensitive than many other species," Brutlag says. 

The issue in automotive antifreeze, whether it's in radiator coolant or deicing windshield wiper fluid, is ethylene glycol. Pet Poison Helpline receives more calls from cat owners about windshield wiper fluid, which also contains a high concentration of ethylene glycol. 

Signs to Watch For in Antifreeze Poisoning in Cats

Cats go through three stages of antifreeze poisoning, according to Brutlag.

The first stage occurs in the first 12 hours and can include vomiting, drooling, seizures, excessive thirst, or excess urination. "The cat can look 'drunk,' similar to what happens to people drinking alcohol," Brutlag says. 

The second stage occurs within 12 to 24 hours. While the early signs may disappear,  the antifreeze may be permanently damaging your cats' internal organs, especially the kidneys.

In the third stage that happens during the first 24 hours after exposure, cats may start showing a lack of appetite, lethargy, drooling, vomiting, seizures, and coma. Without treatment, death is likely. 

For a good prognosis and recovery, Brutlag says veterinarians "want to get to these cats and start treatment within a few hours." Prognosis is poor for cats who don't begin treatment after the first three or four hours after their exposure to the substance.

If you think your cat drank antifreeze, Brutlag says you'll want to act fast. "If you see your cat ingesting antifreeze, run to the veterinary clinic," she says. "Don't wait and see what's going to happen."

Treatment for Antifreeze Poisoning in Cats

When veterinarians suspect, or if pet owners can confirm, that a cat has consumed antifreeze, it's possible your veterinary clinic will induce vomiting. They then may administer medication through an IV tube that blocks your cat's kidneys from further metabolizing the poison.

Because cats often receive a different alcohol as part of their treatment to help counter the ethylene glycol, they can become extremely "drunk" and will need to be hospitalized for observation at the clinic during treatment.

However, Brutlag says the damage done by antifreeze is different from other kinds of chronic kidney disease. "If it's too late and the cat has already metabolized the antifreeze, we can sometimes get the kidneys healthy again, but there may be irreversible damage," Brutlag says.

"Cats can live with kidney damage, depending on how severe and the cause," Brutlag says. "Antifreeze poisoning is pretty dire, unlike with some chronic renal failure where cats can live for years."

How to Prevent Antifreeze Poisoning on Cats

The advice is simple: Keep antifreeze with ethylene glycol out of reach of curious cats and in places where bottles can't accidentally tip over onto a counter surface or the floor. If you spill antifreeze, clean it up right away. If you live in a cold-weather climate, think twice about using products with ethylene glycol in water gardens or other outdoor places accessible to your cat. 

If you want to steer clear of ethylene glycol, there are so-called "pet-safe" antifreeze products. These use propylene glycol instead, which must be consumed in larger amounts to be toxic to cats. Propylene glycol absorbs water and is "generally recognized as safe" by the U.S. Food and Drug Administration. It shows up in food colors, flavors and drugs as well as products with antifreeze, but is not allowed in cat foods. 

Accidents happen. Pets eat, drink, and are exposed to toxic and unhealthy chemicals. Your cat (and her precious kidneys!) will appreciate your efforts to keep her curious mouth away from antifreeze. But if exposure to the chemical does occur, a trip to a vet who can help should happen ASAP.