Ethylene Glycol Poisoning in Dogs

What is ethylene glycol?

Ethylene glycol, a sweet-tasting, odorless liquid, is the active ingredient in most automotive antifreeze products. Ethylene glycol can also be found, in lower, less harmful, concentrations, in some windshield de-icing agents, hydraulic brake fluid, motor oils, solvents, paints, film processing solutions, wood stains, inks, printer cartridges, etc.


How do dogs get ethylene glycol poisoning?

Dogs may be attracted to ethylene glycol by its sweet taste. Many animals will voluntarily drink ethylene glycol if antifreeze is spilled or leaks onto garage floors or driveways. Ethylene glycol has a very narrow margin of safety – which means only a tiny amount can result in severe poisoning. As little as half a teaspoon per pound of a dog’s body weight can result in fatality.

What are the signs of ethylene glycol poisoning?

Ethylene glycol poisoning is divided into three stages.

Stage 1: (within 30 minutes of ingestion): The signs include lethargy, vomiting, incoordination, excessive urination, excessive thirst, hypothermia (low body temperature), seizures, and coma.

Stage 2 – 12 to 24 hours after ingestion: Some of the signs seem to dramatically improve, luring pet owners into a false sense of security. However, during this stage, dogs become dehydrated, and develop an elevated breathing and heart rate.

Stage 3 – (36-72 hours after ingestion): At this stage, signs of severe kidney dysfunction, which is characterized by swollen, painful kidneys and the production of minimal to no urine, may occur. Progressive depression, lethargy, lack of appetite, vomiting, seizures, coma, and death may be seen.

It is critical that you bring your dog to a veterinary clinic if you know or even suspect that he has consumed ethylene glycol, or if he is exhibiting any of the early symptoms. Do not wait; time is of the essence and immediate treatment is essential! Dogs must be treated within 8-12 hours of ingesting antifreeze, as the antidote only has a narrow time period to work. Left untreated, the animal may die.

How do veterinarians confirm ethylene glycol poisoning?

The best way to confirm ethylene glycol poisoning is by measuring the blood concentration of ethylene glycol. A test to determine the blood levels can be done at some veterinary diagnostic laboratories or human hospitals. This testing method is very accurate, but not always available in the middle of the night. In addition, a test kit that can be used in the veterinary clinic is available to detect the amount of ethylene glycol present in the bloodstream. However, these types of tests may not be as accurate, and false positives can be seen (for instance, false positives may occur from products with similar chemical structures such as propylene glycol, glycerol, mannitol, isopropyl alcohol, sorbitol, etc.). Also, if this test kit is run too late, it may test falsely negative; in other words, since peak levels of ethylene glycol are detected in the first 1- 6 hours after ingestion of the toxin, it is important that this test kit be used early in the course of suspected poisonings. By as early as 24 hours after ingestion, insufficient ethylene glycol remains to allow detection on this blood test; however, the damage to your pet’s body from ethylene glycol has already occurred.

Are there other tests that can indicate ethylene glycol poisoning?

Ethylene glycol is converted by the liver into toxic byproducts that are damaging to the kidneys. This damage can be identified in a serum biochemistry profile by increases in the levels of creatinine and BUN (blood urea nitrogen) that are normally removed from the blood by the kidneys. However, these tests are not specific for ethylene glycol toxicity, and by the time these blood tests show evidence of kidney failure, the prognosis is grave to poor (since it is too late to treat with the antidote). Acidosis (acidic blood) can also be detected through the biochemistry profile. A urinalysis may also confirm ethylene glycol poisoning and underlying kidney damage by the presence of dilute urine containing blood, protein, cellular casts (plugs of cells which have taken the shape of dying tubules in the kidneys), and calcium oxalate crystals (which are seen with ethylene glycol poisoning). Lastly, a special black-light lamp (Wood’s lamp) can sometimes be used to examine the urine, muzzle, and paws of the patient to look for the presence of the warning dye which is added to automotive antifreeze.

When in doubt, if you suspect your dog has ingested ethylene glycol, immediate veterinary attention is imperative as the prognosis is very poor once clinical signs have developed. Again, because the antidote (fomepizole) is only effective if given within 8-12 hours in dogs, it is imperative that you see a veterinarian immediately. When in doubt, you or your veterinarian can contact Pet Poison Helpline (800-213-6680) 24/7 for life-saving assistance in managing a poisoned patient.
*Pet Poison Helpline, is an animal poison control service available 24 hours, seven days a week for pet owners and veterinary professionals who require assistance treating a potentially poisoned pet. Pet Poison Helpline is available in North America by calling 800-213-6680. Additional information can be found online at www.petpoisonhelpline.com. Pet Poison Helpline is not directly affiliated with LifeLearn.