Antifreeze Poisoning (Ethylene Glycol Toxicosis) in Cats

Antifreeze is a potent toxin, so interaction with any amount of antifreeze is an emergency. The lethal dose of ethylene glycol for average-sized cats is 1 to 2 teaspoons. Exposure to antifreeze occurs through ingestion and skin contact. **If interaction with any amount of antifreeze is observed or suspected, immediate medical treatment is necessary. It is not advised to wait and see if symptoms develop before seeking medical attention. Once symptoms arise, the condition is usually fatal. **

Most households regularly keep products which contain ethylene glycol, so nearly all pets can potentially be exposed. Antifreeze in particular is used commonly in areas where winter temperatures drop below freezing, so reports of this poisoning usually spike in the winter months.

Symptoms vary by dosage and time, presenting in three stages. Early symptoms extend from 30 minutes to 12 hours after exposure. After 12 hours, symptoms seem to improve temporarily before a rapid decline due to kidney failure.

Ethylene glycol toxicosis is caused by exposure to a toxic dose of ethylene glycol. Improper storage and disposal of antifreeze-containing household products are common, making accidental poisoning a substantial risk. Ethylene glycol may be found in unexpected places outside the garage like in HVAC systems, portable basketball hoop bases, ballpoint pens, paints, stamp pads, plastics and cosmetics.

If ethylene glycol ingestion has been observed, diagnosis is self-evident.

If ingestion is not directly observed, diagnosis is difficult.

Next steps include:

• Blood tests
• Urinalysis
• Physical examination

Ethanol is sometimes used as an antidote for ethylene glycol toxicosis and is more likely to be effective when given early. Other treatments include:

• Inducing vomiting
• Gastric lavage
• Administration of activated charcoal and sodium sulfate
• IV fluids and supportive care to minimize kidney damage

Note: Induction of vomiting and administration of activated charcoal should always be performed by a veterinary professional. There is no safe way to induce vomiting at home.

Ethylene glycol is absorbed quickly in the intestines, therefore intervention within 2 hours of ingestion is critical to positive outcomes. Once neurological symptoms develop, inducing vomiting is no longer safe and the prognosis is very poor.

Interactions between cats and ethylene glycol are avoidable. In cases where antifreeze must be used, restricting the cat’s access to where it is used or stored, or choosing a pet-safe alternative such as propylene glycol is advisable.

Ensuring all items containing ethylene glycol are properly maintained, securely stored away from pets, and disposed of properly lowers the risk of accidental poisoning. Discontinuing outdoor roaming or supervising pets when outdoors is also advisable to avoid risk of poisoning, as use and improper storage of ethylene glycol is common.

Ethylene glycol poisoning is a common form of poisoning in cats, particularly during the coldest months of the year when antifreeze usage is highest.

Treatment options include

• Ethanol
• Inducing vomiting
• Gastric lavage
• Administration of activated charcoal and sodium sulfate
• IV fluids and medications