A reader asked me to warn everyone of the dangers of antifreeze left out where animals can reach it. Because of this request, I will repeat an article originally published in January 1981.
Ethylene glycol and di-ethylene glycol are the chemical names for permanent antifreeze, a common product used in the radiators of cars in winter to prevent freeze-up, and often retained in the machine during summer to help prevent rust build-up and protect the air conditioner.
For whatever good reasons it is used, antifreeze is toxic to pets and children, and should be stored out of reach and disposed of in such a way that neither animals nor toddlers get a chance to taste it.
Dogs and cats are attracted to ethylene glycol by its aroma and having once tasted the sweet liquid, animals seem to acquire a taste for it and will return for more.
Toddlers also find a fascination for this semi-thick, pourable compound, and, like all youngsters of that age group, will explore by sticking their fingers into the puddle (or container) and then putting their fingers in their mouths.
The toxic or poisonous compound, ethylene or di-ethylene glycol, upon ingestion, is absorbed into the bloodstream. Part of the compound may be eliminated from the body through the urine and the breath, but the majority is metabolically converted into oxalic acid, a substance unusable by the body and, in quantity, also toxic. The oxalic acid combines with calcium (coming from food or from calcium stores in the body) to form insoluble calcium oxalate crystals. The crystals collect in the kidney tubules and cause inflammation and the condition called renal tubular obstruction. Once the crystals have formed and the obstruction has taken place, little can be done to save the animal. Fortunately, few toddlers have had the opportunities to ingest sufficient anti-freeze to cause permanent damage.
To understand how deadly the substance can be, the lethal dose for a cat is 1.1 milliliter or less than ¼ teaspoon per pound. For a dog, the fatal dose is 3.3 milliliter or ¾ teaspoon per pound.
Treatment should begin before any symptoms appear. If your animal is seen tasting or drinking anti-freeze, induce vomiting with small amounts of hydrogen peroxide or warm salt water.
Call the veterinarian immediately so he or she can be prepared to flush your pet’s stomach when you arrive and start intravenous feedings. Certain compounds given through the vein for about three days will inhibit the oxidation of the ethylene glycol and may save your pet.
If you do not witness the actual consumption of anti-freeze, but there is some that your animal has access to, you may notice trembling, convulsions, vomiting, ataxia (lack of coordination) or depression.
If not treated at once, acute bleeding in the gastrointestinal tract, coma and death will be the outcome. Therefore, it is essential to store antifreeze out of reach and dispose of used antifreeze completely, not leaving it in puddles, or in the gutter or in open containers.
For your information, a non-toxic compound, propylene glycol, is available that takes the place of ethylene glycol. Also, some brands have a bittering agent added to them so pets will leave it alone.