Heat Exhaustion in Dogs

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.1 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.