Poisoning by antifreeze that contains ethylene glycol is one of the most common small animal toxicities. Antifreeze has a sweet taste that appeals to dogs. Exposure typically occurs when antifreeze drips from the car radiator and is lapped up by the pet. Dogs may also drink from the toilet bowl in vacation homes that have been winterized by pouring antifreeze into the bowl. Less than 3 ounces (88 ml) is enough to poison a medium-size dog. The poison primarily affects the brain and the kidneys. Signs of toxicity are dose- related, and occur within 30 minutes to 12 hours after ingestion. They include depression, vomiting, an uncoordinated “drunken” gait, and seizures. Coma and death can occur in a matter of hours. Dogs who recover from acute intoxication frequently develop kidney failure one to three days later. Death is common.
Treatment: If you see or suspect that your pet has ingested even a small amount of antifreeze, immediately induce vomiting and take your dog to the veterinarian. If treatment will be delayed, administer activated charcoal to prevent further absorption of ethylene glycol. A specific antidote (4-methylpyrazole) is available to treat poisoning. It is most effective when given shortly after ingestion and early in the course of treatment. Intensive care in an animal hospital may prevent kidney failure.
Prevention: This common cause of pet and child poisoning can be prevented by keeping all antifreeze containers tightly closed and properly stored, preventing spills, and properly disposing of used antifreeze. A new generation of antifreeze products contain propylene glycol rather than ethylene glycol. The U.S. Food and Drug Administration has labeled propylene glycol as “generally recognized as safe,” which means it can be added to foods. However, that is in small amounts. Ingesting propylene glycol antifreeze can cause lack of coordination and, possibly, seizures, but is unlikely to be fatal.