Dog Owners Educational League, Inc.

Antifreeze poisoning ranks as one of the top ten toxicologic problems in dogs and cats. The major toxic component of antifreeze is ethylene glycol. Ethylene glycol comprises 95 percent or more of the permanent antifreeze preparations or mixtures used for liquid cooled automobile and other gasoline engines. In addition it may be found as a component of brake fluids, hydraulic fluids, and rust inhibitor solutions. For pet animals the major source of poisoning is from ethylene glycol used in antifreeze for automobile engines.

The incidence of antifreeze poisoning increases significantly in the fall of the year, when radiators are being drained and new antifreeze is being incorporated into automobile and other machinery cooling systems. Exposure occurs when solutions containing ethylene glycol are left sitting in open containers or allowed to carelessly drain on to floors. Pets allowed access to or kept in garages or shops are prone to consume antifreeze. Apparently the semisweet taste is palatable to most small animals. Animals are also known to lick the inside of containers used in pouring or mixing antifreeze solutions. The possibility of heavy exposure is even greater if the animal does not have an adequate supply of drinking water therefore using the antifreeze solution as a source of supply for its fluid needs.

As little as 1 ounce may be fatal to a 15 pound dog and as little as 1/3 ounce may be fatal for a 10 pound cat. Ethylene glycol is rapidly absorbed and metabolized once consumed by the animal. Signs of toxicity may appear as early as 6 hours after consumption of ethylene glycol. After absorption and metabolism starts toxic intermediaries develop rapidly which results in serious central nervous system damage and kidney damage and may cause death within 12 to 36 hours after ingestion.

Diagnosis is difficult and often depends on the animals owner's observations of the animal consuming the material or giving a careful history of the animals environment. Typical symptoms which may occur within 1 - 6 hours after consumption may include incoordination, vomiting, rapid heart rate and respiratory rate progressing to coma and death. If the animal survives this initial set of symptoms and lives 24 - 48 hours beyond the initial stages kidney failure results and the animal usually dies as a result of uremia and acidosis.

Successful treatment of antifreeze poisoning requires immediate and vigorous therapeutic procedures. Favorable results are dependent on rapid recognition, diagnosis, and application of therapeutic measures. The amount of ethylene glycol the animal has consumed is also important in that most animals are incapable of responding favorable to any therapy when receiving more than the previously mentioned amounts (1 ounce fatal to 15 pound dog, 1/3 ounce fatal to 10 pound cat).

Remember that prevention of exposure to ethylene glycol is the best measure of protection you can provide to your pet!