Sweet Pet Poison: Your Guide to Cat & Dog Antifreeze Poisoning

You’ll find antifreeze in surprising places, not just in the garage. For instance, the liquid in snow globes can poison pets when the toy breaks. Recently, social media shared many stories of antifreeze poisoning cats from the liquid in broken snow globes. The liquid tastes sweet, so it’s very appealing for sweet-loving dogs to drink or lick up spills on the garage floor. Puppies are the worst, eating anything that doesn’t move faster than they do. Cats also are at risk when they walk through puddles and lick and groom the liquid off their body. Other places you find antifreeze include:

• Paints and solvents
• Brake fluid
• Windshield-washer fluids
• De-icers
• Fire extinguishers
• Detergents
• Printer cartridges
• Ballpoint pens

People also use antifreeze to winterizing outdoor pools, the toilets in winter campsites, or fountains to prevent freezing.

Composed of ethylene glycol, the odorless, colorless fluid is used to protect cars from freezing temperatures. It’s also used to remove rust and found in some color film processing solutions used in home darkrooms. If you catch your pet drinking antifreeze, call your emergency vet.

Antifreeze is deadly. It takes very little to make the dog or cat mortally sick. About one-half teaspoon per pound of pet is lethal. That means a ten-pound cat could ingest as little as five teaspoons and be affected, while an average-size dog weighing 45 pounds would need to drink less than three ounces. All dogs and cats are at risk, but those younger than three years old are affected most often, probably because of the curious nature of youth. Most poisonings take place during the fall, winter, and early spring when we use more antifreeze.

Your pet’s survival depends on quick treatment. The pet’s body rapidly absorbs the toxin. Peak blood concentrations happen within one to three hours after ingestion. You’ll notice the first symptoms one hour after poisoning. Pets can die from kidney failure in as little as four to eight hours.

One of the earliest signs is an increased thirst. That results in urine output of approximately six times the norm, within three hours of ingestion. The pet may develop sudden potty accidents when that happens. Once absorbed into the bloodstream, the poison enters the brain and spinal fluid, causing neurologic signs. You can see:

• Staggering as though drunk
• Weakness
• Depression
• loss of appetite
• panting
• excessive drooling
• rapid heart rate

Convulsions, though rare, can also be a sign of poisoning. Although the substance is not particularly irritating to the gastrointestinal tract, sometimes pets vomit. The more antifreeze the pet passes in the urine early on, the better, because the substance is at first relatively harmless.

But within only a couple of hours, the body changes ethylene glycol into oxalic acid. This extremely toxic substance used as a bleaching and cleaning agent destroys the urinary tract and severely damages the kidneys. It’s not the antifreeze itself, but the oxalic acid that kills pets. Oxalic acid can combine with calcium to form crystals which block the flow of urine.

Don’t be fooled when your pet acts recovered in about 12 to 18 hours. Although symptoms fade, kidney damage continues, sometimes over a week’s time. The pet eventually stops peeing, and renal failure causes coma and death.

If you see your pet drink antifreeze, or if you can’t get to the vet within two hours, make him vomit out the poison immediately. Then get him to the vet. Beyond this two-hour window, the poisoning will already be in his system and vomiting won’t help. Don’t induce vomiting if your cat or dog acts depressed, is not fully conscious, or acts drunk.

To induce vomiting, give 3% hydrogen peroxide to your pet in a dose of one teaspoon per five pounds of body weight. For big dogs, give no more than three teaspoons at once. If the pet doesn’t vomit, you can repeat the same dose up to three times, given 10 minutes apart until the dog vomits. Then get him to the veterinarian.

Administering activated charcoal, available from your drugstore, also improves your pet’s chance of survival. After you’ve induced vomiting, or if you’re unable to get him to vomit, give him the crushed tablets mixed with water. Charcoal binds the poison to prevent its absorption in the intestinal tract. Follow up any first aid by a veterinarian’s evaluation as soon as possible. Treatment begun after 24 hours following poisoning offers only a slim chance of recovery. Refer to more pet first aid information here.

Your vet offers the best options for how to cure antifreeze poisoning. Dogs need to receive treatment within five to eight hours, but cats are more susceptible to toxins and need treatment within three hours. Treatment prevents further absorption or metabolism of the poison, and increases urination to get rid of it. Up to three hours following ingestion, the veterinarian will flush the dog’s stomach with a saline/charcoal solution. Intravenous fluid therapy helps head off dehydration and also encourages your dog to urinate as much antifreeze as possible before it’s changed into its more lethal form.

For a while, veterinarians used an effective antidote called fomepizole aka Antizol. Because of problems getting the ingredients, it’s no longer available. That makes prevention of poisoning, and early supportive treatment even more important for your pet.

Perhaps you’ve heard about and wondered, can you treat antifreeze poisoning with alcohol? Yes! Treatment comprises hospitalizing the pet to administer 100 proof ethanol alcohol intravenously over several days. This forces the liver to deal with the alcohol instead of metabolizing the antifreeze into oxalic acid. That also gives the pet more time to urinate out the unchanged antifreeze. The treatment, though, poses additional risks to pets, so prevention remains the best policy.

What if your dog suffers kidney failure? People suffering from kidney failure benefit from dialysis machines, but this luxury is rarely available for our pets. Major veterinary schools may have the specialized equipment.

But peritoneal dialysis offers an effective, low-tech alternative your vet may perform. THe doctor pumps fluid into the pet’s abdominal cavity where it absorbs waste the damaged kidneys can’t process. Then the veterinarian draws the waste-filled fluid back out. Peritoneal dialysis gives the kidneys more time to heal, so that normal function can return. It takes three to four weeks for kidneys to return to normal or near normal function. That can require aggressive therapy, including hospitalization.

Severe kidney damage won’t respond to treatment. Kidney transplants work extremely well in cats, with the procedure offered at some specialty vet clinics. But dogs aren’t great candidates for transplant. A dog’s body rejects a donated kidney that doesn’t closely match their own tissue. Littermates are the best chance of a match. Take steps now to prevent poisoning by antifreeze and save your pets and you the expense and heartbreak of treating antifreeze poisoning.

Prevent the possibility of poisoning by keeping antifreeze out of your pet’s reach. Make garages and storage areas off limits to your pets. Dispose of drained radiator fluid in a sealed container and be sure to clean spills immediately. Cover the liquid with cat litter, sand, or baking soda to absorb the mess, and make it less appealing to curious pets.

Today, many manufacturers throughout the United States add a bitter flavoring agent called denatonium benzoate to antifreeze. That makes them less attractive to pets and kids. Look for alternative antifreeze products that use less-toxic chemicals such as propylene glycol. You’ll still need to remain vigilant, of course. Here are a few veterinarian-recommended brands that are safer for use around pets and wildlife, and ask your veterinarian for a recommendation.:

• Star Brite Bio-Safe
• Star Brite Star-Cool
• Sierra 

Keep a good first aid reference on hand for peace of mind, like The First Aid Companion for Dogs & Cats. But always make your vet the first call, for the sake of your pet.

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Amy Shojai, CABC is a certified cat & dog behavior consultant, a consultant to the pet industry, and the award-winning author of 35+ pet-centric books and Thrillers with Bite! Oh, and she loves bling!