What is heatstroke in dogs
This article is part of our seasonal calendar of dog health, which shows you the dangers your dog faces over the year.
Heatstroke is a dangerous overheating of the body. While a healthy dog has a body temperature of about 38 to 39 degrees, in heatstroke it rises above 40 degrees. From this point the body can no longer release the heat, proteins and cells are damaged, and without quick help organ failure and death are possible.
The reason lies in cooling. Unlike humans, dogs hardly sweat; they release heat almost only through panting and a little through the paw pads. If the surroundings are too hot, airflow is lacking or exertion is added, this mechanism is no longer enough. That is exactly why a dog is so much more sensitive to heat than many people think.
The distinction from exhaustion is important. Short, strong panting after play is normal. But if your dog does not calm down despite rest and shade, staggers or vomits, this is no longer a simple case of tiring out but a medical emergency. How serious is shown by a large British analysis by the Royal Veterinary College: of the recorded dogs with heatstroke, around one in seven died, which corresponds to about 14 percent. The earlier you act, the better the chances.
How heatstroke develops, the typical risk situations
Most heatstrokes happen in a few, well-known situations. A large analysis by the Royal Veterinary College even shows that the majority of cases do not arise in the car but through movement and exertion in the heat, around 74 percent. Knowing the typical situations means you can avoid them.
- Movement and exertion in the heat are the most common trigger. Extended fetching, jogging or running alongside the bike push even fit dogs to their limit, sometimes even on moderately warm days.
- The walk in the midday heat quickly overtaxes the dog, especially on open areas without shade.
- The parked car is the most insidious danger. Even at 20 degrees outside temperature, the interior climbs above 40 degrees within a few minutes, even in the shade and with a slightly open window. A dog never belongs alone in a car.
- Hot asphalt additionally radiates heat and burns the paws on top of that.
- The garden or balcony without shade and without fresh water becomes a trap on hot days, especially when the dog is alone for hours.
In all these cases heat from outside and exertion from inside come together, and it is exactly this combination that tips the body temperature over.
Focus on the cuddles, we'll focus on the costs.
These dogs are especially at risk
In principle any dog can suffer heatstroke, but some much more easily than others. Especially at risk are short-nosed breeds such as the Pug, French and English Bulldog or Boxer, because their narrowed airways make panting, and therefore cooling, harder.
Older dogs, puppies and overweight dogs also regulate their temperature less well. Added to this are dogs with dense or dark fur, animals with heart or respiratory conditions and dogs that are not used to heat. If your dog belongs to one of these groups, you should plan especially carefully on hot days and consistently avoid exertion.
Heatstroke in dogs, recognising the symptoms
Heatstroke develops in stages. The earlier you step in, the better the chances. You should know these signs:
| Stage | Signs | What to do |
|---|---|---|
| Early warning signs | heavy, fast panting, restlessness, increased drooling, bright red tongue and gums | immediately out of the heat, shade, offer water, start cooling |
| Progressing | staggering, weakness, vomiting, diarrhoea, fast heartbeat, stringy saliva | cool actively and head for the vet without delay |
| Life-threatening | dark red or bluish gums, collapse, cramps, unconsciousness | emergency, straight to the clinic and keep cooling on the way |
Diarrhoea in the heat can also be an accompanying sign, as can sudden apathy. When in doubt, the rule is: better react once too early than too late.
What to do in a heatstroke, first-aid measures step by step
If you suspect heatstroke, every minute counts. Proceed in this order:
- Get your dog out of the heat immediately, to a shady, cool and airy place.
- Offer it lukewarm water to drink. Never force it in, a dazed dog can choke.
- Cool it quickly with cool, not ice-cold water, ideally over a large area down to the skin and starting at the paws, legs, belly and the inner thighs. Provide airflow, for example with a fan or in the driving wind, this boosts cooling through evaporation.
- If you have a thermometer, measure the temperature rectally. From around 40 degrees the situation is critical. Stop active cooling as soon as your dog becomes calmer and noticeably cooler, so that it does not become too cold.
- Drive to the vet immediately, even if your dog already seems better. It is best to call ahead so the practice is prepared.
Just as important is what you should not do:
- No ice water, no ice and no ice-cold dousing. The sudden strong cold constricts the blood vessels and thus hampers heat release from the body core. Ice on the skin also triggers cold shivering, which generates additional heat.
- Do not wrap your dog in wet towels. They trap the heat instead of releasing it.
- Do not force it to keep walking and do not let it rest in the heat.
How to act calmly and correctly in an emergency is also shown in our guide on first aid for dogs.
From what temperature it becomes dangerous for dogs
There is no fixed limit, because it depends on breed, age, fitness and humidity. As a guide: from about 25 degrees you should move walks to the cool edges of the day in the early morning and late evening and avoid exertion. In muggy weather it becomes critical even earlier, because the humid air makes panting less effective. Important: with heavy exertion, heatstroke looms even on only moderately warm days; in the Royal Veterinary College data many cases occurred already at moderate outside temperatures.
For the ground, the simple seven-second test helps. Hold the back of your hand on the asphalt for seven seconds. If it is too hot for you, it is too hot for the paws, and then you stay on shady paths or meadows. And in the car the rule applies without exception: even at a mild 20 degrees the interior temperature rises to life-threatening levels within minutes, so your dog is never left behind there.
Focus on the cuddles, we'll focus on the costs.
Possible late effects and why the vet is still necessary
Heatstroke sometimes has after-effects over hours, even when the dog already appears fit again on the outside. The severe overheating can damage the kidneys, liver and the gastrointestinal tract, disturb blood clotting and, in severe cases, affect the brain. Some of these effects only show up with a delay.
That is why every dog with suspected heatstroke belongs in veterinary care, even if the first-aid measures have worked. Only then can internal damage be recognised and treated early. Many owners wonder what late effects heatstroke can have, and the answer is clear: get it checked, do not wait.
How to prevent heatstroke
The good news is that almost every heatstroke can be prevented. With a few habits you get safely through the summer:
- Never leave your dog alone in the car, not even briefly and not in the shade.
- Move walks to the early morning and the late evening.
- Always provide shade and fresh water, indoors and out.
- Avoid extended romping and sport in the heat.
- Help with cooling down using a cooling mat, a damp cloth to lie on or a quiet, cool room.
- Plan especially carefully for at-risk groups such as short-nosed breeds, seniors and overweight dogs.
That way your dog stays relaxed even on hot days, and you never even get into an emergency in the first place.
What a heatstroke emergency costs and how Dalma protects you
Heatstroke is often an emergency outside regular consultation hours, so in the evening, at the weekend or on holidays. Then emergency-service surcharges apply, and depending on the severity, examinations, infusions and inpatient monitoring are added. The care of your dog should be in the foreground, not the invoice.
With Dalma's pet health insurance the treatment is reimbursed within your tariff up to 4 times the GOT rate, and we cover emergency-service surcharges against proof. You choose a reimbursement of 80 or 100 percent and an annual benefit limit from 1,500 euros to unlimited. If you are unsure whether the situation is acute, FirstVet's telemedicine helps for an initial assessment, but in an emergency it does not replace the trip to the practice.
