High-risk situations
- Midday or afternoon walks, especially on tarmac
- Left in a car, on a balcony or in a room without air-conditioning
- Flat-faced breeds: French bulldogs, pugs, bulldogs, shih tzus
- Overweight, elderly, heart-disease or thick-coated dogs
- Hard exercise without water
Signs
- Heavy panting that does not settle
- Thick, ropey drool
- Bright red gums and tongue, turning purple or pale later
- Wobbling, unable to stand, collapse
- Vomiting or diarrhoea, possibly with blood
- Body temperature above 40°C (normal 38 to 39°C)
- Seizures, coma
First aid (while getting ready to leave)
- Move to shade with moving air; air-conditioning or a fan.
- Wet the whole body with tepid or room-temperature water, especially the belly, armpits and paws. No ice water: it constricts blood vessels and traps heat.
- Offer small amounts of water; do not force it.
- If you have a thermometer, stop cooling at 39.5°C to avoid overshooting.
- Go to the hospital immediately, even if the dog seems better. Kidney failure, brain swelling and clotting problems appear hours later.
At the hospital
- Controlled cooling, intravenous fluids, oxygen
- Blood tests to monitor kidneys, clotting and electrolytes
- 24 to 48 hours of hospital observation to manage complications
Most dogs treated early recover fully; delay raises the death rate sharply.
Prevention
- Walk early morning or after dark; test the pavement with the back of your hand, and if you cannot hold it for five seconds, do not walk
- Carry water and a folding bowl; offer it every 15 minutes
- Never leave a dog in a car, even with windows open
- Keep flat-faced breeds in air-conditioning in summer and shorten walks
- Weight loss is the most effective prevention for an overweight dog