Antifreeze is the most dangerous everyday substance in a Calgary garage. It tastes sweet, animals drink it willingly, and a very small amount causes fatal kidney failure. A cat can be poisoned by a few licks. If you suspect any exposure at all, this is an immediate emergency, not a wait and see.
Why this becomes a risk in September
Calgary usually sees its first frost in the second half of September, and the city responds accordingly. Antifreeze gets topped up, cooling systems get flushed, jugs come out of the back of the garage, and vehicles that have been fine all summer start leaking as seals contract in the cold.
That combination puts the substance into circulation in exactly the places pets spend time: garage floors, driveways, back lanes and the strip of gravel beside where the car is parked. A slow radiator leak leaves a small puddle overnight, and by morning it has been found.
The other autumn factor is that outdoor water sources start freezing. A cat or a dog that would normally drink from a puddle or a bowl finds those frozen and goes looking. A puddle of antifreeze does not freeze at the same temperature, so it can be the only liquid water available in a cold garage.
Why it is so dangerous
Two things make antifreeze different from most household hazards.
The first is that it tastes sweet. Almost every other toxic substance in a home tastes unpleasant enough that animals stop after a taste. Antifreeze is the opposite, and animals will drink it deliberately and finish what is there.
The second is the amount required. For a cat, a volume equivalent to a few licks, less than a teaspoon, can be enough. For a medium-sized dog, a few tablespoons. These are quantities that leave no visible trace on a garage floor.
Once swallowed, it is broken down by the body into compounds that form crystals in the kidneys. Those crystals cause kidney failure, and once that is established it is frequently irreversible. Everything about the outcome depends on how quickly the animal is seen, which is why we are being blunt in this article.
The three stages, and the trap in the middle
Antifreeze poisoning follows a recognisable pattern, and the middle stage is what costs animals their lives.
- First, roughly thirty minutes to twelve hours. The animal appears drunk. Wobbly, uncoordinated, disoriented, possibly vomiting, drinking and urinating more than usual. Some appear mildly euphoric or unusually vocal.
- Then, roughly twelve to twenty four hours. The animal appears to recover. This is the trap. They seem brighter, steadier, more themselves. Owners quite reasonably conclude that whatever it was has passed. Internally, the damage is progressing.
- Then, from around twenty four to seventy two hours. Kidney failure becomes apparent. Vomiting, complete loss of appetite, lethargy, mouth ulcers, and producing little or no urine. By this point the options have narrowed considerably.
The window in which intervention works best is measured in hours, and it is largely within that first stage. In cats it is shorter still. This is the clearest example in veterinary work of a situation where phoning at hour two rather than hour twenty changes everything.
What to do if you suspect exposure
- Phone us immediately. Do not wait for signs, do not wait for morning, and do not wait to be sure. Go to our urgent and emergency care and call on the way.
- Say the word antifreeze on the phone. It changes the triage immediately.
- Bring the container if there is one, or photograph the label and the spill.
- Note the time as precisely as you can, and the largest amount that could plausibly have been drunk.
- Do not try to make your pet vomit at home. An animal that is already unsteady is at real risk of inhaling stomach contents.
- Do not give anything by mouth, including water, milk or anything from your own cabinet.
Suspicion is enough. You do not need to have seen your pet drink it. A cat found unsteady in or near a garage in October is worth a phone call on that basis alone.
What happens at the clinic
Time is the whole conversation, so triage is immediate. There is a specific approach that works against antifreeze, and its effectiveness depends almost entirely on how soon after ingestion it begins. That is a veterinary decision made on the timing and the animal in front of us, so please phone rather than researching it.
Alongside that, our pet diagnostics assess kidney function, blood chemistry and urine, and those tests are repeated over the following days because the picture changes. Fluid support and close monitoring are usually part of it, and most animals need to stay with us rather than go home the same day.
For a broader look at how to respond in the first minutes of any suspected poisoning, our guide to first aid for pet poisoning covers the general principles. Antifreeze sits at the most urgent end of everything described there.
Preventing it around the house
- Check under your vehicle regularly. A fresh puddle on the garage floor or driveway needs identifying, not ignoring. Bright green, orange, pink or blue are all common colours.
- Clean spills immediately and thoroughly. Absorb with cat litter or sand, sweep it up, bag it, then wash the area down with plenty of water. Do not leave it to evaporate.
- Store containers sealed and high up, or in a locked cupboard. A cardboard box on a garage floor is not storage.
- Never pour it down a drain or onto the ground, including a back lane. Take it to a proper disposal facility.
- Look for products based on propylene glycol, which are considerably less dangerous than the traditional ethylene glycol ones. Less dangerous is not the same as safe, so store them properly too.
- Keep pets out of the garage while any vehicle work is happening, and check the floor before letting them back in.
- Watch the back lanes on walks, particularly in the weeks after the first hard frost.
- Provide unfrozen water outdoors if your pets spend time outside, so they have no reason to look elsewhere.
A word about neighbours and community cats
Outdoor and community cats in Bowness are especially exposed, because they shelter under and beside parked vehicles and they find garage puddles. If you have a leak, it may not be your own cat that finds it. Fixing a leak promptly is a genuinely neighbourly act at this time of year.
Frequently asked questions
How much antifreeze is dangerous for a cat?
Far less than most people expect. A quantity smaller than a teaspoon can be enough for a cat, and a few tablespoons can be enough for a medium-sized dog. Do not use the size of the puddle to decide whether to call, because a lethal amount for a cat leaves almost no visible trace.
My dog walked through a puddle but I do not think he drank any. Should I call?
Yes, please call. Dogs and cats groom their paws, so walking through it and licking afterward is a genuine route of ingestion rather than a theoretical one. Wash the paws with soap and water and phone us to talk it through.
My cat seemed drunk last night but is completely normal this morning. Is that reassuring?
No, and this is the most important question on this page. Apparent recovery after twelve hours or so is a recognised stage of antifreeze poisoning, not a sign that the danger has passed. Please bring your cat in today rather than waiting to see how the day goes.
Is pet-safe antifreeze actually safe?
Products based on propylene glycol are substantially less toxic than the traditional kind, and switching is worthwhile. They are not harmless, and an animal that drinks a quantity of any automotive fluid should still be assessed. Store and clean up after them with the same care.
Are there other sources besides car radiators?
Yes, and they get overlooked. Windshield washer fluid, brake fluid, some paints and solvents, and the liquid inside snow globes and some portable toilets can all contain related compounds. Check what is stored at floor level in your garage and basement, not just what is in the car.
Can antifreeze poisoning be survived?
Animals seen very early, before kidney damage is established, can do well. Once kidney failure has developed the outlook becomes much poorer, particularly in cats. That difference is entirely about timing, which is why we would rather take ten unnecessary calls than one that came a day late.
Speak to the team at Bowness Animal Hospital
If you suspect any antifreeze exposure at all, phone us immediately. Do not wait for signs.
Published by the team at Bowness Animal Hospital.
This article is for general educational purposes only and is not a substitute for an in-person veterinary examination or advice about your individual pet. If you have an urgent concern about your pet, contact Bowness Animal Hospital or your nearest emergency veterinary hospital right away.
Bowness Animal Hospital
Unit 52, 7930 Bowness Road NW, Calgary, AB T3B 0H3
Phone: (587) 391-3911
Hours: Monday to Friday 9:00 AM to 7:00 PM; Saturday 9:00 AM to 5:00 PM; Sunday and statutory holidays closed