Check out our handy factsheet!
The most common cause of heat stroke or hyperthermia is leaving a dog in a car with inadequate ventilation. The dog’s body temperature in this situation can elevate very rapidly, often within minutes.
“Their primary way of regulating body temperature is by panting.”
It is important to remember that dogs cannot control their body temperature by sweating as humans do since they only have a relatively small number of sweat glands located in their footpads. Their primary way of regulating body temperature is by panting.
Other common causes of heat stroke include being left in a yard without access to shade or water on a hot day, being exposed to a hair dryer for an extended period of time, and excessive or vigorous exercise during hot temperatures. Excited or excessively exercised dogs are sometimes at risk even if the environmental temperature and humidity does not seem high. This is particularly true if dogs are kept in a poorly ventilated environment or a dog house.
Dogs with a restricted airway such as brachycephalic breeds (flat-faced dogs such as pugs, boxers, and bulldogs) are at greater risk. In these breeds, clinical signs of heat stroke can occur when the outside temperature and humidity are only moderately elevated.
Dogs that are muzzled for any reason can be at greater risk since their ability to pant is restricted by the muzzle.
Any infection causing fever (pyrexia) can lead to hyperthermia. Seizures or severe muscle spasms can also elevate the body temperature due to the increase in muscular activity.