Early signs your dog may be too hot

Most owners imagine heatstroke as a dog collapsing. In reality, heat-related illness often begins earlier and more quietly: panting that suddenly sounds different, a dog who drops behind, or the enthusiastic walker who lies down and will not continue.

Recognising that change matters. UK veterinary research found altered breathing and lethargy were the most commonly recorded signs in dogs presenting with heat-related illness. Exercise is also a major trigger — a dog can become dangerously hot on a walk even when they were never left in a car.

Know your dog’s normal pant

Panting after activity is normal, but context and recovery matter. A comfortable dog should begin to settle when exercise stops and they reach a cool place. Be concerned when panting:

• becomes much faster, louder or more forceful than usual
• continues to intensify during rest
• is accompanied by difficulty drawing breath
• comes with a very wide or elongated tongue
• appears while the dog is resting before activity

Flat-faced dogs can deteriorate quickly because their shortened airways are less efficient at moving air. Any change in breathing effort deserves an earlier stop and a lower threshold for veterinary advice.

Early behaviour changes are easy to miss

Watch for:

• slowing down or lagging behind
• repeatedly seeking shade or water
• lying down and refusing to move
• restlessness or inability to settle
• reduced response to familiar cues
• excessive drooling or foaming
• bright red or unusually pale gums

These signs are not a reason to “finish the last five minutes”. Stop exercise immediately.

Moderate and severe signs need urgent action

Weakness, shaking, vomiting, diarrhoea, collapse, confusion, poor coordination, seizures, unconsciousness or blood in vomit or diarrhoea suggest more serious heat-related illness. The condition can continue to damage organs even if a dog seems to perk up during initial cooling. Do not wait for every symptom and do not rely on a home temperature reading to rule heatstroke out.

What to do: cool first, call the vet

1. 1Stop all activity and move the dog into shade or a cool, well-ventilated area.
2. 2Begin cooling immediately with cold tap water. Pour it over the body, avoiding the nose and mouth. Start steadily so a conscious dog does not panic.
3. 3Create airflow with a fan, breeze or air conditioning.
4. 4Offer a small amount of cool water if the dog is conscious and able to drink — but never force it.
5. 5Call a vet immediately and follow their instructions. If travelling, keep cooling on the way where it is safe to do so.

Current UK veterinary guidance supports cold-water cooling. For a young, healthy, conscious dog comfortable in water, cold-water immersion with the head kept above water can be effective. For older dogs, flat-faced dogs, dogs with underlying disease, unconscious dogs or dogs who may panic, pour water over the body while protecting the airway. Use whatever clean water is available if it is cooler than the dog — do not delay searching for the “perfect” temperature.

What not to do

• Do not cover or wrap the dog in wet towels — they can trap heat and reduce airflow.
• Do not force water into the mouth.
• Do not put water over the nose or mouth.
• Do not give human medicines.
• Do not wait to see whether a cooling mat, vest or drink fixes the problem.
• Do not transport without cooling first if cooling can begin safely where you are.

Dogs who need extra caution

Any dog can overheat. Risk is higher in:

• flat-faced breeds
• overweight dogs
• very large, elderly or very young dogs
• thick-coated dogs
• dogs with heart, airway or lung conditions
• dogs exercising intensely or becoming highly excited

Prevention begins with permission to stop

Check temperature, humidity, sunlight, surface and route before leaving. Walk earlier, shorten the route, carry water and plan shade. Most importantly, let your dog’s behaviour overrule the itinerary. If in doubt, do not go out. A missed walk can be replaced with enrichment. A medical emergency cannot be undone by good intentions.