Canine hyperthermia and overexertion

Most of us are familiar with the term hypothermia, and understand that it means a dangerously low body temperature that can ultimately prove fatal if it is not correctly quickly and carefully. However, fewer people tend to be familiar with the term hyperthermia, which is the exact opposite of hypothermia, and means a dangerously high body temperature, which can pose just as much risk to dogs but in a very different way.

Hyperthermia in the dog means a dangerously high body temperature, and in the vast majority of cases, hyperthermia occurs as a result of a combination of hot weather and overexertion, such as if your dog is playing or exercising vigorously in the midday heat in the summer. Some dogs are more sensitive to high temperatures than others, and are less able to control their own body temperature and cool themselves down, which can be a risk to most brachycephalic breeds of dog like the Cavalier King Charles spaniel and the Affenpinscher.

In this article, we will look at hyperthermia and its relationship to overexertion in the form of exercise-induced hyperthermia in more detail, including how it occurs, the risks that accompany it, and how you can protect your dog. Read on to learn more.

What causes exercise-induced hyperthermia?

Exercise and exertion naturally raise the heart rate, causing more blood to be pumped around the body at a higher speed, which raises the dog’s body temperature. On hot days, this, in combination with the high ambient temperature, combines to pose the risk of dangerous overheating, and so hyperthermia is most commonly associated with hot weather, vigorous play, and not taking the time to cool down and drink water.

Various factors can contribute to making certain dogs more sensitive to heat and more apt to developing hyperthermia than others, and some of the core risks and other factors to bear in mind include:

• Different dogs have different levels of resistance to heat and exercise; for some dogs, they are at risk of developing hyperthermia after just ten minutes or less of very vigorous activity in hot weather, while other dogs may take hours to become dangerously hot.
• Dogs sweat through their paws, and at a much lower rate than humans sweat. Sweat is one of the body’s methods of cooling itself down, and if your dog is too hot and their sweating cannot keep up with their cooling needs, they will be at risk of hyperthermia.
• The higher the temperature is, the greater the risk of hyperthermia.
• The thickness and length of your dog’s coat also plays a part.
• Older dogs are more sensitive to temperature than younger ones, but younger dogs are more likely to be boisterous and active in hot weather.
• Your dog’s weight, general health and fitness levels all play a part too.

The symptoms of canine hyperthermia

You should monitor your dog carefully when they are exercising hard and/or the weather is hot, and avoid a lot of exertion during hot weather. Make sure that your dog takes a break, has some water and cools down regularly too, regardless of the weather.

Some of the symptoms of canine hyperthermia include:

• Drooling and bright pink, sticky gums.
• Very heavy or laboured panting or fast breathing.
• Drinking an excessive amount of water.
• A high body temperature (over 39.3 degrees Celsius).
• Collapse.
• Sudden weakness and unresponsiveness.
• A fixed gaze or apparent inability to focus.
• Seizures in advanced cases.

It is important to remember that overheating and hyperthermia are not the same thing-dogs often overheat or approach the overheating threshold when working hard, but their temperature will return to normal within fifteen minutes of ceasing exercising and making attempts to cool down. Hyperthermia is harder to correct, and will remain elevated for a long time-potentially several hours- after ceasing activity.

Correcting hyperthermia in the dog

Hyperthermia is a potentially dangerous condition, as it can lead to a range of systemic problems including damage to the nervous system if your dog’s temperature is dangerously high for a prolonged periods of time.

In order to prevent further problems and potential damage, you will need to cool your dog down and get their body temperature back within the healthy normal range as soon as possible, but this does not mean dunking your dog in an ice bath! Cooling a hyperthermic dog back down again needs to be done carefully, and if possible, under the direction of your vet.

Don’t use ice or freezing water to cool your dog down, but instead, give them a cool or lukewarm bath or use wet towels to cool them down across as much of the body as you can. Keep monitoring your dog’s temperature, and if it is not on its way down within an hour of attempts to correct it, call your vet.