October 31, 2025
Ethylene Glycol (Antifreeze) – The Silent Winter Poison That Can Harm Dogs and Other Animals
Winter has arrived, Christmas markets are just around the corner, and we all love that magical holiday feeling. But right now, in this most beautiful time of the year, there hides one of the most dangerous poisons for dogs: ethylene glycol, the main ingredient in antifreeze.
This is the time of year when antifreeze is used the most. People are topping up their car cooling systems and preparing their vehicles for freezing temperatures because antifreeze is essential for protecting the engine from freezing.Without it, the water inside the engine would freeze, expand, and could cause serious damage such as cracked pipes, radiators, or even the engine block itself.
Although most people associate antifreeze with winter, it is actually used all year round because it has another important role: it prevents engines from overheating in summer. Thanks to its chemical composition, antifreeze raises the boiling point of the coolant, helping the engine stay stable even during very hot weather. That is why every car, regardless of the season, always contains this liquid.
In other words, antifreeze is the invisible guardian of your car’s engine, but also a silent danger for our dogs because it contains ethylene glycol, a substance that is extremely toxic and dangerous even in the smallest amounts.
What is Ethylene Glycol and Why Is It So Dangerous?
Ethylene glycol is the main chemical compound found in most types of antifreeze. It is a colorless, thick liquid with a sweet taste, and that sweet taste is exactly what makes it so dangerous for dogs, cats, and other animals.
They cannot recognize it as poison. On the contrary, the sweet smell and taste attract them, so just a few licks from the floor, a puddle under a car, or a punctured antifreeze bottle can be enough to cause fatal poisoning.
How It Affects the Body
Once swallowed, ethylene glycol is quickly absorbed into the bloodstream and metabolized into highly toxic compounds.
In the liver, it turns into glycolic acid and oxalic acid, which attack the kidneys, nervous system, and heart.
These toxic byproducts damage kidney tissue, disrupt electrolytes, and cause kidney failure, which is often fatal if not treated immediately.
What makes this poison especially dangerous is that the first symptoms seem harmless. The dog may just appear a bit sleepy, disoriented, or “drunk,” while serious internal damage is already occurring.
How Much Is Enough to Kill?
Only 4–5 ml of ethylene glycol per kilogram of body weight can be lethal.
(That means just one or two teaspoons can kill a medium-sized dog.)
For cats, it is even worse. Just a few drops can be fatal.
That is why veterinarians warn pet owners every winter to be extremely careful. Poisoning often happens by accident: a dog licks a few drops from the pavement, from a puddle under a car, or even from its paws after walking through a contaminated area.
Why It Is Especially Dangerous in Winter
During cold months, when antifreeze is used more frequently, the number of poisonings rises.
Near parking lots, garages, and even driveways, tiny spills or drops of antifreeze can mix with snow or water, becoming invisible but still deadly.
That is why during winter it is important to:
• Never let your dog lick snow or puddles near vehicles.
• Always wipe their paws after walks.
• If you spill antifreeze, wipe it up immediately and rinse with plenty of water, even if it is just a small amount.
Modern Antifreeze – Safer, But Still Dangerous
In recent years, manufacturers have started creating alternatives to traditional ethylene glycol-based antifreeze because of its extreme toxicity.
The most common substances used in “safer” formulations today include:
• Propylene glycol – Often used as a less toxic alternative to ethylene glycol. Many labels promote it as “pet-safe” or “eco-friendly.” However, it is still not meant for ingestion. Large amounts can cause vomiting, dehydration, and other systemic issues, and cats are particularly sensitive to it.
• Glycerin (glycerol) – Another less harmful substance used in some decorative liquids and antifreeze products. While it has a lower toxicity, large amounts can still cause vomiting, diarrhea, and other issues.
• Ethanol or short-chain alcohols – Sometimes present in small concentrations. While less toxic than ethylene glycol, alcohol is also poisonous in sufficient doses.
Why There Is Still a Risk
• Even though propylene glycol and glycerin are less toxic, they are not harmless. Large doses can still cause dehydration, electrolyte imbalance, and organ issues.
• Cats are often more sensitive to these substances than dogs.
• A label that says “pet-safe” usually means the risk of acute toxicity is lower, but it does not mean it is safe if consumed.
• Color and label claims can be misleading. Always check the ingredients. Some antifreeze blends contain a mix of compounds.
Other Products That May Contain the Same Dangerous Ingredient
It is important to know that antifreeze is not the only product that can contain ethylene glycol or other similar toxic compounds.
Many products used in winter to melt or unfreeze surfaces can be just as dangerous.
These include:
• De-icing sprays and windshield washer fluids used for car windows and mirrors.
• Lock de-icers and frost removers.
• Coolants and heating fluids for vehicles, garages, or machinery.
• Even some household cleaning products and paints.
All of these may contain ethylene glycol or propylene glycol, which means they should be treated with the same level of caution.
Always keep such products in tightly closed containers, stored high and out of reach of pets and children.
Even small spills or drops can be enough to cause serious harm if licked by an animal.
What to Do If You Suspect Your Dog Licked Antifreeze
If you even suspect that your dog came into contact with antifreeze, act immediately. When it comes to this poison, time can mean the difference between life and death.Even small amounts can be fatal, so do not wait to “see what happens.”
How to Recognize Antifreeze Poisoning
• The dog appears sleepy or “drunk” (unsteady walk, loss of balance)
• Vomiting, excessive drinking, frequent urination
• Later: lethargy, refusal to eat, no urination
If you notice any of these signs, go to the vet immediately.
1. Call Your Veterinarian Right Away
Tell them exactly:
“My dog may have licked antifreeze (ethylene glycol).”
The vet will instruct you to come in immediately.
If you know which product was involved, bring the bottle or take a photo of the label, as it helps determine the right treatment.
2. Do Not Try Home Remedies
Do not give milk, oil, or anything without calling the vet first.
Do not induce vomiting unless your vet specifically tells you to.
These can make things worse and delay proper care.
3. If Antifreeze Got on Fur or Paws
Rinse the affected area with lukewarm water and mild shampoo, dry thoroughly, and do not let your dog lick it.
Wear gloves when cleaning, as ethylene glycol can irritate human skin too.
4. At the Clinic – Every Minute Counts
The sooner your dog reaches the vet, the higher the chance of survival.
The vet may administer an antidote such as fomepizole or ethanol, give IV fluids, and monitor kidney and liver function.
The best survival chances are when treatment starts within 2–4 hours after ingestion.
After 12 hours, survival chances drop drastically.
5. While You Wait for Help
If your vet is far away, call the nearest clinic and let them know you are coming with a suspected ethylene glycol poisoning so they can prepare.
While on your way, do not withhold water.
If your dog wants to drink, let them. Drinking water may slightly slow absorption and help keep them hydrated until professional help is available.
Of course, do not force them to drink if they do not want to.
When in doubt, it is always better to visit a vet unnecessarily than to arrive too late.This poison acts fast and silently. Symptoms can look mild while serious kidney damage is already happening. Quick action saves lives.
Thankfully, I am not writing this from personal experience. I learned about the dangers of antifreeze early on from my veterinarian, who explained how even the smallest amount can be deadly for dogs.
Later, I read more on the topic and was shocked to discover that even some decorative snow globes can contain ethylene glycol or similar substances. If such a globe breaks and your pet licks just a few drops, it could be enough to cause fatal poisoning.
That is why I decided to write about this topic and raise awareness among pet owners. Sometimes the most innocent-looking situations, such as a small spill near the car or a broken decoration, can have tragic consequences.
I am sure the same applies to children, but they are easier to keep away from danger. Dogs, on the other hand, are naturally curious and tend to sniff and lick everything around them.
My sincere advice is: If possible, do not keep antifreeze at home. Let that always be your mechanic’s job, or if you fill it yourself, do it in a place where your pets cannot reach. And always dispose of empty bottles immediately, because my own dogs sometimes like to play with plastic bottles, and that could be extremely dangerous if they once contained antifreeze.
I truly hope this article helps someone. If even one dog is protected because you read this, it will have been worth writing.
If you have an idea for a topic you would like me to cover next, please share it in the comments. I would love to hear your suggestions.
