Heatstroke in dogs: spot it early and cool them correctly

In a Greek summer, heatstroke is one of the most common — and most preventable — pet emergencies. Dogs cool themselves mainly by panting, which doesn't work well in heat and humidity. Once a dog's body temperature passes about 40 °C, its organs start to suffer.

It's not just hot cars

Nearly three-quarters of canine heatstroke cases happen during walks, play or exercise. A long walk at midday, a game of fetch on the beach or a run beside a bike can be enough — and exertional heatstroke can happen even on days that don't feel very hot.

Dogs at higher risk:

• Flat-faced breeds — French Bulldogs, Pugs, Bulldogs, Shih Tzus
• Overweight dogs
• Giant breeds and thick-coated breeds
• Puppies and older dogs

Warning signs

Heatstroke gets worse fast. Signs usually progress from:

1. Heavy panting, restlessness, tiredness
2. Drooling, vomiting, diarrhoea, very red or pale gums, stumbling
3. Confusion, seizures, collapse, bloody vomit or diarrhoea, unconsciousness

If you see any of these after heat or exercise, start cooling immediately and call the nearest emergency vet.

How to cool a dog — the current advice

Veterinary first-aid guidelines published in 2026 recommend cooling on the spot before travelling, because every minute at high temperature matters:

• Move the dog into shade or a cool room.
• Pour or run cool tap water over the body, especially the belly and inner thighs where the coat is thin. Soak right down to the skin. Running water from a hose or shower works better than a single bucket.
• Keep water away from the face — never pour it over the head of a panting or collapsed dog.
• Use a fan or air conditioning if you have one.
• Offer small amounts of cool water to drink, but don't force it.

Don't drape wet towels over the dog and leave them there — they trap heat. Don't use ice-cold water or ice baths.

When to stop cooling

If you have a thermometer, stop active cooling once the rectal temperature reaches 39.7–40 °C, dry the dog and go to the vet — cooling further can make the temperature drop too low. Without a thermometer, cool for 15 minutes and then drive to the vet, keeping the windows open or air conditioning on.

Why a vet visit is still essential

Even a dog that seems to recover can develop kidney damage, clotting problems or brain swelling over the next 24–48 hours. Always get it checked.

Prevention in a Mediterranean summer

• Walk early in the morning and late in the evening. Test the pavement: if it's too hot for the back of your hand, it's too hot for paws.
• Always carry water and a bowl.
• Never leave a dog in a car, even with windows open, even "for a minute".
• Skip strenuous exercise on hot days, especially with flat-faced breeds.