Ottawa summers can catch people off guard. A beautiful July day turns sweltering by noon, and what started as a morning walk through the Glebe or along the canal becomes something your dog can’t handle the way you’d expect.
Heatstroke in dogs moves faster than most owners realize. The early signs are easy to miss or dismiss, just a hot dog on a hot day. By the time the serious signs appear, you’re already in emergency territory. Knowing the difference between the two is what buys you time.
Why do dogs overheat so easily
Dogs don’t sweat through their skin. They cool themselves almost entirely through panting, which pushes air over the moist surfaces of their mouth and airways to release heat. On a hot, humid Ottawa afternoon, that system becomes dramatically less effective. The air they’re breathing in is nearly as warm as the air they’re trying to push out.
A dog’s normal body temperature sits around 38°C to 39°C. Heatstroke starts around 40°C to 41°C. Above 41.5°C, organ damage can begin. And that escalation can happen in minutes, not hours. Especially in a parked car, on a sun-baked trail, or during exercise that goes on a bit too long.
The early signs of overheating in dogs
This is the window where you can actually intervene before things get serious. Watch for heavy, rapid panting that doesn’t settle when your dog rests. Excessive drooling more than usual, sometimes thick or stringy. A dog that’s restless and can’t seem to get comfortable, or one that suddenly just wants to lie flat in the shade. Gums that look a brighter red than normal.
At this point, getting them somewhere cool and offering water may be enough. But keep watching. This can shift quickly.
Don’t wait if you see these signs
Gums that have turned white, gray, or blue. Vomiting or diarrhea, especially if bloody. Legs that are trembling or giving out. A dog that’s staggering, stumbling, or has collapsed. Loss of consciousness. Seizures.
If you’re seeing any of these, you’re past the management-at-home stage. Get moving and apply cool water (not ice cold) to your dog’s body on the way to the clinic.
Some dogs are in more danger than others
Any dog can overheat. But French Bulldogs, Pugs, English Bulldogs, Boxers, and other flat-faced breeds are at significantly higher risk because their shortened airways make panting far less efficient. If you have a brachycephalic breed, your threshold for concern should be lower, and your precautions should be higher.
Heavy-coated breeds like Huskies, Bernese Mountain Dogs, and Saint Bernards are also more vulnerable than their winter-ready appearance might suggest. So are older dogs, overweight dogs, and any dog with an underlying heart or respiratory condition.
What to do in the moment
Move them to shade or air conditioning immediately. Offer cool water in small amounts, but don’t let them gulp a liter all at once. Apply cool (not ice-cold) water to the areas with the best blood flow: the neck, armpits, groin, and paw pads. A fan helps if you have one available.
Two things not to do: don’t wrap them in a wet towel and forget about it (it traps heat rather than dispersing it), and don’t use ice or ice water. Rapid cooling causes blood vessels near the skin to constrict, which actually slows the cooling of the core. Cool water, steady airflow, and get to a vet.
Even if your dog seems to recover with some cooling — come in anyway. Heatstroke causes internal damage that isn’t always visible, including kidney injury and clotting problems that can surface later.
Keeping it from happening in the first place
Walk in the early morning or near sunset when the pavement has had a chance to cool. Never leave a dog in a parked car! Even a few minutes with the windows cracked can push interior temperatures to dangerous levels. Always bring water on any outdoor outing and offer it frequently, not just when your dog asks for it. On particularly hot days, keep outdoor time short and keep an eye on how your dog is doing throughout.
The pavement test is a useful habit: if you can’t hold your bare hand flat on the asphalt for five seconds comfortably, it’s too hot for paw pads.
FAQ
What’s the difference between heat exhaustion and heatstroke?
Heat exhaustion is the earlier stage — your dog is struggling but hasn’t yet reached a dangerous internal temperature. Heatstroke is when that temperature is high enough to start causing real damage. Both need attention, but heatstroke is a genuine emergency where every minute matters.
Can a dog get heatstroke inside the house?
Yes. A home without air conditioning on a genuinely hot Ottawa day, a sunny room with no airflow, or a space like a sunroom or enclosed garage can reach dangerous temperatures. It doesn’t have to happen outside.
My dog cooled down and seems fine now. Do we still need to see a vet?
Yes. Internal damage from heatstroke, especially kidney injury and clotting issues, can occur even when a dog appears to have bounced back. A vet assessment after any heatstroke episode is important, not just for treatment but to understand if anything needs to be monitored going forward.
Is panting always a sign of overheating?
Not always. Dogs pant from excitement, after exercise, and when they’re anxious too. The context matters. Panting that’s laboured, doesn’t settle with rest, and comes with other symptoms like restlessness or red gums is the concern.
How hot is too hot to walk my dog in Ottawa?
Above 25°C with notable humidity, keep walks short and shaded. Above 30°C, shift to early morning or evening, and keep exercise minimal. When in doubt, do the pavement test first.
Worried your dog is overheating?
Don’t wait it out! Call Galaxy Vets Urgent Care & Walk-In : Ottawa. Open every day noon to midnight.