Heat stroke, or hyperthermia, is a potentially deadly condition in dogs and is defined by a body temperature of greater than 104 degrees F. This condition is rarely seen in cats. The danger zone with heat stroke is when the body temperature is elevated between 106-109 degrees F for a prolonged amount of time. It can ultimately lead to central nervous system dysfunction and multi-organ failure if left untreated. Heat stroke is life threatening, but it can be prevented!
What causes heat stroke?
Heat stroke is either exertional and non-exertional. Common causes of exertional heat stroke include strenuous exercise in a hot and humid climate. Non-exertional causes are related to being left outside with lack of water and no shade. A very common cause of heat stroke in dogs is being left in the car with limited ventilation. Body temperature can rise to the danger zone within minutes. It is also important to remember that dogs and cats are unable to get rid of heat or lower body temperature with sweating like humans can. Their primary means of heat dissipation is panting.
Risk factors include a warm and humid environment with limited access to water and/or increased muscle activity. Obesity, thick hair coat, brachycephalic breeds like bulldogs, boxers, pugs, etc.), and lack of acclimatization also play a direct role. It is important to always leave plenty of fresh water and a shade structure if leaving your pets outside for prolonged amounts of time. In the summer months taking your dog on their daily walk or run in the early mornings or evenings when it is cooler outside is crucial. Houston summers are much too hot to have “outdoor” pets or to pursue play time or long walk while the sun is shining.
The symptoms vary in severity, but most commonly heat stroke victims show excess panting, drooling, weakness, muscle tremors/spasms, vomiting, and diarrhea. Alterations in mentation, seizure activity, and multi-organ failure can also be seen.
If you suspect heat stroke in your pet, remove them from the hot environment. Initially, access to water, a fan, and rapid cooling with room temperature water are recommended. If possible, determine rectal temperature and record it. Transport your pet to the closest veterinary facility. Frequent monitoring of the temperature is vital. It is important to stop cooling mechanisms once the body temperature has been lowered to 103-104 degrees F. Your veterinarian can further assess and determine appropriate treatment. Often, intravenous fluid therapy, oxygen support, and ongoing medical management are required.
Severe hyperthermia is a disease that affects nearly every system in the body. The prognosis for heat stroke is complex and directly related to the degree of hyperthermia and the duration of time the body temperature stays elevated. Heat stroke is a medical emergency that needs to be addressed immediately. Thankfully, it can be prevented!