Heat Stroke in Dogs

Heat Stroke in Dogs

June 24, 2022

With the summer heat waves upon us in the northern hemisphere, we should revisit the subject of heat stroke in dogs, as many dog owners do not realise how dangerous this avoidable condition can be, or how quickly it can develop.

Here is an excerpt from my book From Wolf to Supermutt and Everything in Between, to remind us all to be extra careful, and not to  leave our dogs in parked cars, or hot unshaded back yards, or go jogging with them in the middle of the day when temperatures soar.

Thousands of dogs that die annually from heatstroke. Even relatively mild outside temperatures can generate extreme heat in locked cars within minutes. For example, mild outside temperatures of 24°C become 40°C in a closed vehicle within twenty minutes and close to 50°C in thirty minutes. Similarly, while outdoor summer temperatures often reach 30°C and over, they can generate internal vehicle temperatures of 40°C within ten minutes and close to 50°C in twenty minutes. Excessive heat gradually increases a dog’s core temperature, as they only sweat through the pads of their feet and cannot lose heat quickly enough from panting. The average body temperature for dogs is 38.3–39.2°C, increasing to over 40°C within fifteen minutes. Once their core body temperature reaches over 41.5°C, and cells start to break down. As the gut leaks toxins into the body, cells begin to die, and a devastating inflammatory response takes place, causing blood clots that obstruct blood vessels throughout the body. This damage is rapidly followed by multi-organ failure and death.

Naturally, we understand the importance of a daily walk, but not at the expense of their health. Walking dogs in high temperatures is just as dangerous as leaving them unattended in cars and can result in severe and irreversible damage and death. In hot weather, pavements radiate intense heat, especially for dogs low to the ground. A foolproof way to test the temperature of the pavement is to place the back of your hand on the hot surface, and if you cannot hold it there for seven seconds, it is too hot for your dog. Additional good advice is to avoid walking during the canicula of the summer months and remember that the optimum temperature for walking and exercising dogs is around 19°C. Even though most dogs will tolerate temperatures up to 25°C, dogs with underlying health issues, including obesity, are already at risk. Walking dogs in temperatures over 25°C endangers puppies, obese, flat- faced and especially large dogs.

Throughout the summer heat, I’m constantly appalled by the number of people I see walking or jogging with their dog during the hottest part of the day when temperatures are well over 25°C. Exercise triggers ten times as many heat-related incidents as hot cars, and vets warn that it is best to avoid walking our dogs on scorching days.

How can we tell if our dogs are too hot?

The most obvious sign of heat exhaustion is relatively easy to spot and includes rapid excessive panting and drooling. On the other hand, dehydration is more challenging to determine, and we should watch out for a dry nose and lethargy; therefore, we must ensure that we keep our dogs well hydrated, especially on outings.

In the UK, the 2016 research data shows that vets treated almost 400 dogs for heat-related issues, of which 14% died. Circulatory failure, oxygen deficiency, and long-term damage to brains and organs are the typical consequences of owners unaware they are endangering their dogs’ lives. Not only are dogs left in overheating cars, exercised in extreme heat, but owners often leave them outside, suffering for days in yards that lack shade, in unrelenting temperatures and humidity. From an earlier chapter, you may recall Franky, our dachshund, who refused to walk in temperatures over 25°C. Unfortunately, not all dogs are as intuitive as Franky, so as pet parents, it is up to us to be responsible and protect our dogs from the summer heat. Heatstroke in dogs is avoidable.