FRIDAY, Oct. 29 (HealthDay News) -- It's a fatal attraction: puddles of sweet-tasting antifreeze on driveways and garage floors are hard for thirsty pets to resist.

Just one teaspoon of ethylene glycol -- the toxic ingredient found in antifreeze -- is deadly to a 10-pound cat, and about five tablespoons will kill a Labrador retriever if the antidote isn't given in time, say veterinary toxicologists.

"The most important thing to know about antifreeze is you have a really narrow window for treatment," said veterinarian Dr. Justine Lee, associate director of Pet Poison Helpline, a call center staffed by animal health care professionals who provide treatment advice to owners nationwide.

The antidote must be given to dogs within eight hours after ingestion and cats within three hours, she said. Otherwise, the pet's chances of survival are slim.

The most common source of ethylene glycol is automotive engine antifreeze or coolant. The toxic substance is also found in some air conditioners, imported snow globes, paints, solvents, and color film processing solutions.

Cabin owners in colder regions of the country frequently put antifreeze in toilets to prevent the pipes from freezing while the vacation home is unoccupied. "We see a lot of toxicities here in Minnesota from dogs running into cabins and drinking out of the toilet," Lee said.

Initially, animals appear drunk after imbibing antifreeze. Warning signs include staggering, lethargy, increased thirst, vomiting and possible seizures, explained Dr. Camille DeClementi, a veterinarian and board-certified veterinary toxicologist who serves as a senior director for the American Society for the Prevention of Cruelty to Animals' Animal Poison Control Center.

However, that drunken state is short-lived, she noted, and it may appear as though the pet is recovering when he or she is actually in grave danger: Internal damage is worsening as abnormal crystals form in the kidney, ultimately causing the organ to shut down.

"Once an animal has already gone into kidney failure, there is almost nothing you can do," Lee explained.

If caught in time, she said, the prognosis for recovery is excellent. A blood test confirms if an animal has antifreeze poisoning and whether treatment is needed. Owners should expect a 72-hour hospital stay for poisoned pets, along with a high veterinary bill. Treatment for a medium-sized dog, for example, runs between $2,000 and $2,500.

A better alternative is to protect your pet from accidental exposure in the first place by immediately washing antifreeze spills off driveways and keeping automotive products high on shelves out of reach.

More than a dozen states -- including Arizona, California and New Jersey -- now require manufacturers to add a bittering agent to antifreeze to deter children and pets from drinking it.

However, the ASPCA says there's no published data demonstrating that adding a bittering agent to antifreeze effectively works in repelling dogs, and such products may give pet owners a false sense of security.

A safer alternative is antifreeze containing propylene glycol, which veterinary toxicologists say is still poisonous to pets if large enough quantities are ingested, but it is less likely to kill them.

More information

There's more on poisoning threats to your pets at the ASPCA.