Heat Exhaustion in Dogs: Causes, Treatment, and Prevention


  • What Is Heat Exhaustion?
  • Symptoms
  • Causes
  • Diagnosing
  • Treatment
  • Prognosis
  • Prevention

Heat exhaustion is a term used for moderate overheating, and it is very important to be aware of the signs to know when to seek help and to prevent more serious problems. Just like people, dogs can suffer many health effects from overheating and these can range from mild to life threatening. By knowing what to look for, you can intervene quickly and help your pup by getting treatment right away.

What Is Heat Exhaustion?

Heat exhaustion is the term used to describe moderate effects of overheating. In general, there are three categories used to describe the signs of overheating starting with the mildest form known as heat stress, which may then progress to heat exhaustion and eventually, the most severe state known as heat stroke.

There are a number of factors that can lead a dog to overheat and most are a combination of a hot environment coupled with intense exercise and/or physical problems that interfere with a dog’s ability to cool off properly. Many signs may clue you in that your dog is overheating, and it can look different in each dog. The best thing to do is play it safe and avoid letting your pup get too hot in the first place, preventing serious health problems.

Symptoms of Heat Exhaustion in Dogs

The signs of heat exhaustion can be subtle at first, so watch your dog closely and take action right away if your dog seems to be overheating at all.


  • Panting heavily
  • Restlessness
  • Stopping and laying down repeatedly during a walk or run
  • Trying to drink water frequently
  • Difficulty breathing
  • Drooling excessively
  • Vomiting
  • Diarrhea
  • Collapse


The initial signs include panting heavily even after moving to a cooler location. Some dogs may seem restless if they are out in the heat, or they will stop and lay down frequently during a walk or run if they are getting too hot. They may also stop frequently to try to drink water even if it means disregarding your cues or calls.

This can progress to difficulty breathing, drooling, vomiting, diarrhea, and/or collapse if they continue to overheat. If they do not get cooled off and treated appropriately, they can develop heat stroke, which includes the most severe signs like disorientation, seizures, coma, kidney and liver dysfunction, damage to their digestive tract, blood clotting disorders, and even death.

What Causes Heat Exhaustion in Dogs?

Heat exhaustion and all forms of overheating are often caused by a combination of high temperatures outside, strenuous exercise, and/or underlying health problems that make it more difficult for your pup to cool off. Unlike humans, dogs cannot sweat effectively, so they can only cool off by panting. On hot days, they will have a harder time keeping cool, especially if they are in direct sun without access to shade or if it very humid.

Intense Exercise

Intense exercise can also lead to overheating, even if the outside temperatures are cooler. This is more common in working dogs that may have very long, intense exercise sessions, or in cases of “weekend warrior” syndrome where a dog that is usually sedentary suddenly goes for their first long run and is out of shape. Certain breeds also have a tendency to push themselves too hard with intense exercise including Labs, golden retrievers, springer spaniels, and pit bulls.

Age and/or Medical Problems

A dog’s ability to cool off can also be affected by age and/or underlying health conditions. Very young puppies and older dogs have more trouble regulating their body temperature and can overheat more easily than other dogs. Obesity also impedes a dog’s ability to pant and cool off. Finally, any problems with a dog’s breathing or airways will also make them less effective at panting and more at risk for overheating. This is frequently the case for dogs with smushed faces, known as brachycephalic breeds, like French bulldogs, pugs, English bulldogs and Pekingese.

High Environmental Temperatures

Finally, there are also those cases where dogs overheat because they are trapped in a very hot environment. The most common example of this occurs when dogs are left in a sealed car and the temperature inside the car rises quickly. It has also occurred when dogs are left outside without access to shade on very hot days, or when dogs are transported in the cargo hold of airplanes that lack climate control. Any situation where a dog may experience very high temperatures without relief can become dangerous very quickly.

How Do Vets Diagnose Heat Exhaustion In Dogs?

Diagnosis is usually made based on a combination of the history of events, such as being outside on a hot day, strenuous exercise, or being trapped in a hot car, as well as the dog’s body temperature and other signs of heat exhaustion. A normal body temperature for a dog is between 100-102.5 degrees Fahrenheit. Usually signs of heat exhaustion occur if a dog’s temperature is elevated well above that point, but there is not a clear temperature cut-off for when signs will occur or when they will advance from heat exhaustion to heat stroke as this can be somewhat different for each individual dog.

General guidelines suggest that at temperatures over 105 degrees Fahrenheit, dogs will have signs of heat exhaustion. The most severe signs of heat stroke are always present in dogs with a temperature of 109F or greater, but can occur at lower temperatures as well. Depending on the severity of the signs a dog is experiencing, blood tests and imaging like ultrasound or X-rays may also be helpful to diagnose the extent of problems such as liver damage, kidney failure, and/or bleeding disorders.

How To Treat Heat Exhaustion

Dogs that are overheated can get very sick very suddenly, so act quickly and get your dog to a vet right away if you think they are overheated. This is especially important if they don’t seem to cool off and recover as soon as they are moved to a cooler spot. The most important part of early treatment is to cool the dog off without creating new problems by overcooling.

Even if you are heading straight to the vet, try to wet your dog down with cool water on the way there. Don’t use cold water or ice water since that can actually make things worse. You can pour cool water over your dog or rub your pup down with a wet cloth, just don’t leave the wet cloth on your dog as this can act like a blanket and actually warm them up. You can speed up the cooling process by pointing a high-powered fan right at your damp dog or leaving the windows open while driving to the vet. If your dog is completely alert, offer a bowl of cool water to drink. If your dog is not fully aware or seems uninterested in drinking, do not force any water into their mouth.

For dogs experiencing more serious signs of heat exhaustion or those that just don’t seem to be totally fine after cooling, seek professional help from a vet. Medical treatment will include additional cooling, rehydration measures, and supportive care including IV fluids, oxygen support, as well as protective measures for the kidneys, liver, brain, and/or digestive tract.

Prognosis for Dogs with Heat Exhaustion

Prognosis depends on many factors, including how high the dog’s temperature gets, how quickly they cool down, and what, if any, additional symptoms they have from the heat exposure. Dogs who have higher temperatures for longer periods of time tend to experience more serious effects. If early signs of heat exhaustion are noticed quickly and a dog is cooled down right away before their temperature gets too elevated, they can have an excellent prognosis for a full recovery.

However, some dogs with more mild signs of heat exhaustion may develop severe diarrhea with blood in it, so seek treatment and follow your vet’s recommendations. The dogs that overheat enough to develop heat stroke and have more severe signs including seizures, coma, and/or blood clotting dysfunction have a worse prognosis for recovery and many unfortunately do not survive.

How to Prevent Heat Exhaustion

The best way to avoid heat exhaustion in your pup is with good planning and prevention. Keep your dog as cool as possible on hot days. Avoid exercise or long walks during the hottest times of day and try to take your dog out early in the morning or after sunset when the day is cooler. Always bring water on your walks and try to find walking routes in the shade.

For dogs who are very young, older, overweight, or who have breathing problems, they should be kept indoors with a fan and/or air conditioner on at all times on hot days. These dogs should only be taken out for very brief bathroom breaks when the temperature soars outside, and they should always have water available to them.

While it may be common knowledge for most dog owners, it is worth repeating that you should never leave your pet enclosed in a car even if it doesn’t seem to be that hot outside. Estimates vary, but most sources say that the temperature inside a car can be up to 30-40 degrees hotter than the outside temperature. A dog can easily overheat inside a car even on a day that doesn’t seem so hot to us. Don’t plan to fly with your dog in a cargo hold that lacks climate control, especially if you expect hot weather during the flight or you have a pup with underlying health conditions that makes it hard for them to pant effectively.

In most cases, heat exhaustion can be avoided if you keep a close eye on your pup’s body language and take precautions to keep them cool. And if you do notice signs that your pup looks very hot, remember that quick and early intervention can make a huge difference in getting your pup recovered and back to their favorite activities.

The Spruce Pets uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

  1. Hall, Emily, et al. Proposing the VetCompass Clinical Grading Tool for Heat-Related Illness in Dogs. Scientific Reports, vol. 11, no. 6828, 2021, doi:10.1038/s41598-021-86235-w
  2. Beers, Hannah. Warmer Weather Warning: Go Slow to Prevent Heat Stroke. March 24, 2019. University of Illinois College of Veterinary Medicine.
  3. Bruchim, Yaron, et al. Pathophysiology of Heat Stroke in Dogs- Revisited. Temperature, vol. 4, no. 4, 2017, pp. 356-370., doi:10.1080/23328940.2017.1367457
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