Heatstroke in dogs: signs, first aid and how to prevent it in Colombia’s hot lowlands

What is heatstroke in a dog?

It is what happens when a dog’s body heats up faster than it can cool down and its temperature rises until it damages the organs. It can appear during or after exercise, or simply from being in a hot environment. The Royal Veterinary College (RVC) in London describes it as a potentially fatal condition.

Dogs hardly sweat: they cool down mainly by panting. When the surroundings are very hot, or when the dog cannot pant properly, that mechanism falls short.

How serious it gets depends heavily on how soon you act. In the RVC’s data, 97% of dogs treated for a mild case survived, and only 43% of those that arrived with severe heatstroke. The longer the dog spends with a high temperature, the more damage is done.

What are the signs of heatstroke?

The warning signs are excessive panting, labored or noisy breathing, refusing to keep walking and collapsing. The RVC asks owners to seek veterinary help immediately for any of them. More discreet signs usually come first, and recognizing them in time is what lets you stop the episode while it is still mild.

The RSPCA lists the ones to watch for:

• Heavy panting that does not ease when the dog stops.
• More drool than usual, thick and sticky.
• Noisy breathing or breathing faster than normal, especially in flat-faced dogs.
• Very red gums.
• A racing pulse.
• Trembling or cramps despite the heat.
• Lethargy, clumsy walking or difficulty getting up.
• Diarrhea; if there is blood in it, the case is already severe.

What do I do if my dog has heatstroke?

Cool it right away and then take it to the veterinarian, in that sequence. This is the guidance the Royal Veterinary College promotes with the phrase “cool first, transport second”: putting a hot dog into a car without cooling it first delays the one thing that stops the damage.

Step by step:

1. Stop the exercise and move the dog into the shade or to a cool place.
2. Wet it with water. If the dog is young, healthy and conscious, the most effective thing is to put it in cold water: a pool, a tub, a calm stream, always with its head out.
3. If the dog is old, ill or unresponsive, do not immerse it: pour water all over its body and give it air with a fan, air conditioning or the breeze.
4. Call the veterinarian while you cool the dog and say you are on your way.
5. Transport it once it is cool, with the car cooled down before the dog gets in and with air conditioning or open windows during the trip.

Whatever water is closest will do, on one condition: it has to be cooler than the dog. The hose, a bottle or the mop bucket all work.

Even if the dog seems to have recovered, a veterinarian has to see it: the RVC asks owners to seek veterinary advice as soon as possible in every case, and the veterinarian is the one who decides which tests and which treatment are needed. Always consult your veterinarian, including when the case looks mild.

Do ice, tepid water or a wet towel help?

What helps is water and speed. The RVC calls the old advice to cool slowly and only with tepid water a myth: in its studies, cold-water immersion was the most effective method and produced no harmful effects. Do not lose minutes looking for ice or waiting for the water to “take the chill off”.

Towels need a caveat. More than half of the dogs whose owners had tried to cool them arrived at the veterinarian wrapped in wet towels. It is better than doing nothing, says the RVC, but it cools far less than immersion or than wetting the dog and giving it air. A towel laid over the dog ends up acting as a blanket.

The same study leaves a figure that explains why it matters to spread the word: only 22% of the dogs treated for heatstroke had been cooled before setting off for the clinic.

Which dogs are most at risk?

Any dog can suffer it, but not all equally. An RVC study of more than 900,000 dogs found that flat-faced dogs had twice the risk of the rest, and that weighing more than normal for the breed raised it almost one and a half times.

Risk for each breed compared with the Labrador, according to that study:

One of the breeds on this site appears: the Cavalier King Charles Spaniel. It is not a dog for long midday walks in a hot climate.

The study did not measure coat type, but the list includes breeds with very dense coats. A mountain dog such as the Bernese Mountain Dog has a hard time below a certain altitude; we explain it in the guide on the Bernese in hot climates. Age plays a part too: dogs over two years old were at greater risk than young ones.

How hot does a closed car get?

Very hot, very fast. A Stanford University study measured an average rise of 40 degrees Fahrenheit, about 22 °C, in one hour inside a car parked in the sun, whatever the outside temperature. Of that rise, 80% happened in the first half hour.

The two usual tricks do not work. Leaving the window cracked open had an insignificant effect, both on how fast the car heated up and on the final temperature. Cooling the car beforehand with the air conditioning only delayed the rise by about five minutes.

The RSPCA puts it in figures that are easy to remember: at 22 °C (72 °F) outside, the interior can reach 47 °C (117 °F) within an hour. Twenty-two degrees Celsius is a mild day; in the hot lowlands you start from much higher. There is no such thing as “just five minutes” in the supermarket parking lot.

This also goes for the bed of a pickup truck in the sun and for a crate with no shade. If you are going to be traveling with your dog in Colombia, plan the stops so that the dog is never left alone in the vehicle.

How do you prevent it in the hot lowlands?

By organizing the day around the heat. One of the authors of the RVC study sums it up as changing the times and the intensity of outdoor activity for the dogs most at risk. On the Caribbean coast, in the Llanos and in the hot valleys, that means getting up early or waiting for the sun to go down.

• Walks and play first thing in the morning or at dusk.
• Fresh water and shade always within reach, including in the yard and on the farm.
• No intense exercise in the hottest hours, however much the dog insists with the ball.
• Weight under control: being overweight is a proven risk factor.
• Attention to the first sign: if the dog pants more than usual or falls behind, stop, find shade and wet it.
• Never alone in the car, not even with the window open.

And before all of that comes the choice. Some breeds cope well with heat and others do not, and no amount of care fully makes up for a poor match. If you are still deciding, the guide on which dog suits your city’s climate goes climate zone (piso térmico) by climate zone.