Winter Pet Hazards: Antifreeze

The arrival of a cold snap in Minnesota is a good time to remind ourselves of the dangers of antifreeze. Most antifreeze products contain an ingredient called ethylene glycol. When ingested, ethylene glycol is converted by the body into several other substances (primarily glycoaldehyde, glycolic acid, glyoxylic acid, and oxalic acid) that have numerous toxic effects in the body.  These substances can cause depression in the central nervous system, cardiopulmonary (heart and lung) failure, and renal (kidney) failure.

Ethylene glycol is toxic in very small amounts and very quickly. As little as one teaspoon is enough to cause death in a 10# cat, and as little as two tablespoons is enough to cause death in a 10# dog. Because antifreeze has a very sweet, attractive taste some manufacturers have tried mixing bitter-tasting additives into their antifreeze products with mixed success; as many pet owners know, dogs especially will still eat things that seem like they should taste bad. There are some antifreeze products that contain an alternative ingredient called propylene glycol which is much less dangerous than ethylene glycol; however, it can still be toxic in large quantities

There are usually three stages of ethylene glycol toxicity. The first occurs between ½ hour to 12 hours after ingestion and often starts with drinking large amounts of water and urinating large amounts of dilute urine (called polydipsia and polyuria) and neurologic signs such as depression, confusion, disorientation, uncoordinated movement (ataxia), and  in severe cases coma or seizures. The second stage occurs between 12-24 hours after ingestion and signs may include panting or difficulty breathing and a rapid heart rate. The third stage usually occurs between 24-72 hours after ingestion and signs include severe lethargy, depression, vomiting, loss of appetite, and lack of urine production. At this stage, the toxins cause crystals to form within the kidneys, severely damaging them and leading to kidney failure.

In order for treatment of ethylene glycol ingestion to be successful, it is essential for a pet to receive medical attention as quickly as possible. Treatment consists of giving fluids and medication to block the body from converting the ethylene glycol into the toxic substances so it can be eliminated from the body without doing any damage, but this must be done as soon as possible; after eight hours, the prognosis for recovery becomes very poor and once changes on bloodwork are seen the prognosis is very grave.

Part of what makes ethylene glycol toxicity so dangerous is that unless we see them or find a spilled or chewed bottle, we might not even know our pets got into it until it is too late to treat successfully. Therefore, prevention plays a crucial role in keeping our pets safe from antifreeze. Pet owners should start by using the less toxic propylene glycol antifreeze products. Clean up any antifreeze spills immediately, check your car for leaks on a regular basis, store antifreeze in its original packaging or in clearly labeled containers, and if you drain your radiator or change your antifreeze at home make sure your pets do not have access to the area where you do so. In addition, remember that wildlife or neighborhood pets may be attracted to antifreeze, so keep garage doors closed to prevent access. Consider limiting outdoor cats’ time outdoors during winter weather, and talk to your neighbors if your pets have access to their garages.

If you have any additional questions, please feel free to call or email the clinic.