Too hot to trot: heatstroke in pets explained

Is your pet panting heavily, wobbly on their feet, or not quite themselves right now? Don't wait to finish this article. Get them into shade or air conditioning, pop some cool (not icy) water on their body, and call your vet or nearest emergency vet straight away. Heatstroke moves fast, and every minute counts. Come back to this once your pet is safe and settled.

What actually is heatstroke?

Heatstroke is what happens when a dog or cat's body gets too hot, too fast, and can't cool itself back down. It's genuinely dangerous if it’s left untreated, it can damage organs, trigger seizures, and become fatal within as little as fifteen to thirty minutes.

Here's the tricky part: our pets aren't built to handle heat the way we are. We sweat all over to cool off. Dogs mostly rely on panting. Cats rely on panting too, plus grooming and finding somewhere cool to lie down. When it's hot, humid, or they're stuck somewhere stuffy, that system can fail surprisingly quickly and their temperature just keeps climbing.

If you're reading this because your pup or kitty is acting off on a warm day, trust that gut feeling. It's always better to check and be wrong than to wait and be right.

How do I know if it's heatstroke and not just "being hot"?

In dogs, the early signs can look a lot like normal warm-weather behaviour, which is part of what makes heatstroke so sneaky. Keep an eye out for:

• Panting that's heavy, fast, and doesn't ease off
• Bright red or purple-tinged gums and tongue
• Drooling more than usual
• Wobbliness, weakness, or collapsing
• Vomiting or diarrhoea
• A racing heartbeat
• Seeming dazed, confused, or "not with it"
• Seizures or losing consciousness in severe cases

Flat-faced breeds like french bulldogs, pugs, boxers, and similar, really struggle here, because panting is a lot less effective for them. It’s the same for older dogs, overweight dogs, thick-coated breeds, and dogs with heart or breathing conditions, as they also run a higher risk, even on a day that doesn't feel all that extreme.

Can cats get heatstroke too?

They can, though it's rarer since cats are pretty good at finding shade or a cool tile floor on their own. Watch out for:

• Panting (it can be unusual for cats but it’s always worth taking seriously)
• Lethargy
• Drooling
• Vomiting
• Red gums
• Unsteadiness on their feet

The cats most at risk are usually indoor cats stuck in a stuffy, unventilated room on a hot day, or any cat accidentally shut in a car, garage, or sunroom. If your cat is panting like a dog, don't shrug it off — treat it as urgent.

What should I actually do if I think my pet has heatstroke?

• Get them out of the heat straight away and in shade, air conditioning, a cool room, whatever's closest.
• Cool them down gradually with cool (not freezing) water over their neck, armpits, and groin. Skip the ice, cooling too fast can send them into shock.
• Offer small sips of water if they're able to drink on their own. Don't force it.
• Use a fan to help them cool down

Call your vet or an emergency vet immediately, even if they seem to be perking up. The damage from heatstroke can keep going on the inside even once your pet looks calmer on the outside.

If you're not sure whether what you're seeing is a real emergency or just a hot, tired pet, that's exactly the kind of question worth asking a vet. petinsurance.com.au policyholders can chat with an Australian vet any time of day or night through Live Vet in their Pet Portal, it's a good way to work out whether you need to head straight to the emergency vet or just keep a close eye at home.

Why does this happen more often than people expect?

Because heatstroke doesn't need a heatwave to strike. It can creep up during a normal afternoon walk, a game of fetch, or a few minutes in a parked car. According to PetSure claims data 2025, the highest single heatstroke claim came in at $11,382.95 — a scary reminder that what starts as "my dog seemed a bit off after his walk" can turn into a genuine emergency, fast.

None of this is meant to scare you. It's just a reminder that heatstroke is more common, and can be more serious, than most pet parents realise.

Who's most at risk?

• Flat-faced (brachycephalic) breeds
• Overweight or obese pets
• Very young pets and senior pets
• Thick or double-coated breeds
• Pets with heart, lung, or airway conditions
• Anyone left in a parked car, even briefly, even with the windows cracked
• Pets exercised in the middle of a hot day
• Pets without easy access to shade or water

How do I stop this happening in the first place?

• Walk dogs early morning or evening in hot months and skip the midday sun
• Keep fresh, cool water topped up, at home and out and about
• Never, ever leave a pet in a parked car, even for "just a minute" — the temperature inside can climb dangerously fast, even on a mild day
• Make sure there's shaded, well-ventilated space both indoors and out
• Cooling mats, damp towels, or a paddling pool work wonders for water-loving dogs
• Keep a closer eye on brachycephalic breeds, seniors, and overweight pets
• If the pavement's too hot for your bare hand, it's too hot for their paws

FAQs

Is heatstroke covered by pet insurance?

Heatstroke is generally treated as an accidental injury under most pet insurance policies, since it's a thermal-related condition, and eligible vet costs are usually covered subject to your policy's terms, waiting periods, and exclusions. Some insurers may treat clearly preventable situations — like a pet left unattended in a hot car — differently, so it's worth reading your PDS or checking with your insurer directly if you're unsure.

How hot does it need to be for a dog to get heatstroke?

Dogs can develop heatstroke in temperatures as low as 20–25°C if humidity is high, they've been exercising, or they're stuck somewhere with poor airflow, like a car. It's less about the number on the thermometer and more about heat combined with exertion, humidity, or a lack of shade and air.

How long does it take for a dog to overheat in a hot car?

It can take as little as ten minutes for a car's interior to reach dangerous temperatures — even with a window cracked, even on a day that doesn't feel extreme outside. There's really no safe amount of time to leave a pet in a parked car.

What's the difference between heat stress and heatstroke?

Heat stress (or heat exhaustion) is the earlier, milder stage — heavy panting, tiredness, seeking out shade or water on their own. Heatstroke is the medical emergency stage, where their body can no longer regulate its own temperature and organ damage can begin. If you're not sure which one you're looking at, treat it as heatstroke and get veterinary advice straight away.

Can heatstroke in pets be fatal?

Yes — it's a genuine medical emergency and can be fatal within minutes to hours without treatment. Quick cooling and prompt veterinary care make a real difference to the outcome.