Heatstroke in Dogs: Warning Signs and Emergency Response

On a hot day, a dog can overheat far faster than most owners realise. Dogs do not sweat the way people do — they rely mainly on panting and the small amount of heat lost through their paw pads. When the air is hot and humid, or a dog is exercising hard, panting may not be enough, and body temperature can climb dangerously high. Heatstroke is a genuine emergency, and knowing the warning signs — and what to do in the first few minutes — can make a real difference.

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Heatstroke happens when a dog's body temperature rises above the normal range, roughly 38 to 39 degrees Celsius, and keeps climbing. Once it passes about 41 degrees, organs can start to be damaged. This is why fast, calm action matters, and why prevention is always better than treatment.

What Causes Heatstroke in Dogs?

The most common cause is exercise in hot weather. A long run, a game of fetch at midday, or a walk on hot pavement can push a dog over the edge, especially if the dog is unfit, overweight, or not used to the heat. Dogs left in parked cars are at extreme risk: a car heats up in minutes, even with the windows cracked open, and it is never safe to leave a dog in one on a warm day.

Other risks include being left in a sunny garden without shade or fresh water, a heavy coat with no way to cool down, and excitement or stress, which raises body temperature further. Brachycephalic breeds — those with flat faces and short noses, such as Bulldogs, Pugs, and Shih Tzus — are especially vulnerable because their airways make panting less efficient.

Warning Signs to Watch For

Early signs are easy to miss if you are not looking for them. Watch for heavy, rapid panting that does not settle, drooling that is thicker than usual, and a dog that seems restless, confused, or unsteady on its feet. Bright red gums or tongue, vomiting or diarrhoea, and a dog that lies down and refuses to move are all serious warning signs.

As heatstroke progresses, a dog may become weak, collapse, or even have a seizure. These are late, life-threatening signs. Do not wait for them: act at the first signs of overheating, and call your veterinarian straight away for advice, even while you start cooling your dog.

Dogs Most at Risk

Some dogs need extra care in hot weather. Puppies and senior dogs cope less well with heat, as do overweight dogs and dogs with heart or breathing problems. Thick-coated and double-coated breeds trap heat, and dark-coated dogs absorb more sun. Flat-faced breeds, as mentioned, are at the highest risk of all.

If your dog falls into any of these groups, keep exercise short and gentle in summer, walk early in the morning or late in the evening, and always carry water. A dog that has had heatstroke before is also more likely to suffer it again, so take extra care the following summer.

What to Do Immediately

Stay calm, move fast, and get your dog out of the heat. Move them into shade or indoors, ideally into an air-conditioned room, and offer small amounts of cool — not ice-cold — water to drink. Let them drink freely but in small sips; forcing large amounts of water can cause vomiting.

Cool your dog gradually. Wet their body with cool water, focusing on the belly, groin, armpits, and paw pads, where blood vessels are closer to the surface. Place a cool, damp towel over them and use a fan if you have one. Evaporation is what cools a dog, so a breeze helps a lot.

Keep checking how your dog responds. If panting eases, they become more alert, and they can stand and move, cooling is working — but they still need a veterinarian. Heatstroke can cause damage that is not obvious at first, including kidney and clotting problems that appear hours later, so a vet check is essential even if your dog seems to recover.

What NOT to Do

Do not use ice water or ice baths. Very cold water causes blood vessels to constrict, trapping heat inside the body, and can send a dog into shock. Do not cover your dog with a soaking wet towel and leave it in place, either — as the towel warms up it traps heat, so re-wet it regularly or use a fan.

Do not try to force water down a dog that is collapsed, vomiting, or struggling to swallow, as it can go into the lungs. And do not wait to see if your dog gets better on its own before calling the vet. Heatstroke worsens quickly, and early veterinary treatment gives the best chance of a full recovery.

After the Emergency: Vet Care and Recovery

At the clinic, the vet will check your dog's temperature, hydration, and bloodwork, and may give intravenous fluids, oxygen, or medication to support the organs. Your dog may need to stay for monitoring, even if they look much better. Follow the vet's instructions carefully at home: rest, plenty of water, and no exercise until the vet says it is safe.

Watch your dog closely for the next day or two. Reduced appetite, lethargy, vomiting, or dark urine after a heatstroke episode should be reported to your vet immediately, as these can signal delayed complications.

Preventing Heatstroke

Prevention is simple and saves lives. Walk in the cool parts of the day, keep walks short on hot days, and never exercise a dog hard in heat or humidity. Always provide shade and fresh, cool water outdoors, and bring water on every walk. Never leave a dog in a parked car, even for a few minutes, and never leave a dog in a hot conservatory or unventilated room.

For thick-coated dogs, regular grooming helps air circulate through the coat, and a paddling pool in the shade gives a safe way to cool off. Know your dog's limits: if they are panting hard, slowing down, or seeking shade, that is their way of telling you to stop.

Heatstroke is frightening, but it is also largely preventable. Learn the early signs, act quickly and calmly if you see them, and always get veterinary help. A few minutes of awareness on a hot day can protect the dog who trusts you most.

By PawProper. This article is general information only, not veterinary advice. If your pet is unwell, see a veterinarian promptly.

If your pet shows these warning signs, seek veterinary care immediately — do not wait.