Overview 

Heatstroke is a life-threatening condition that occurs when the body’s temperature rises too high and cannot be cooled effectively. This can cause severe damage to body organs and can result in death.  

Short-muzzle breeds (also known as brachycephalic breeds), as well as older or overweight dogs are at a higher risk for heat stroke. Signs of heatstroke include heavy panting, drooling, vomiting, diarrhea, weakness, collapse and more.  

Treatment involves safely and immediately cooling the pet and seeking intensive care at a veterinary hospital. The most effective strategy to prevent heatstroke is avoiding situations where dogs are at risk of overheating.  

Causes 

Heatstroke occurs from exposure to hot or humid environments, or from overly strenuous exercise. Unlike humans, dogs only have sweat glands on their paws and must rely on panting to cool down.  

The normal body temperature for a dog is between 100.5 and 102.5 degrees Fahrenheit. Heatstroke results when the dog cannot regulate their body temperature, and it rises to 105 degrees Fahrenheit or higher.  

Dogs are most at risk for heatstroke during the summer months if exercising in hot and humid weather, if left outside without adequate shade and water, and if they are left alone in a car — where the temperature can increase rapidly. 

Clinical signs 

• Heavy panting 

• Drooling 

• Bloody diarrhea  

• Vomiting 

• Weakness  

• Confusion 

• Seizures 

• Collapse 

If elevated body temperatures are prolonged, they will cause damage to every organ in the body. Heat stroke commonly leads to acute kidney injury, blood clotting issues and shock.  

Diagnosis 

Heatstroke is diagnosed based on a history of heat exposure and presenting clinical signs. Your veterinarian will perform a physical exam and blood work to check for organ damage.  

Additional testing and monitoring may include blood pressure exams, ECG (electrocardiogram), blood clotting times, sugar and electrolyte levels, and more.  

Treatment 

Heatstroke is a medical emergency and requires intensive critical care. If possible, owners should start cooling their dog immediately — by wetting the dog with cool water and by placing them directly in front of the car’s air conditioning while on the way to your veterinary hospital.  

Once at the hospital, your veterinarian may start the following treatments: 

• Active cooling 

• IV fluids  

• Oxygen 

• Electrolytes and glucose  

• Blood products (e.g. fresh frozen plasma)  

• Antibiotics and medications to protect the gut 

• Pain medications  

• Anti-seizure medications  

Additional medications may be needed based on the individual and their underlying conditions. 

Outcome 

Heatstroke can cause widespread organ damage; and unfortunately, many do not survive. The prognosis depends on how high the body temperature gets and how long it remains elevated.   

Underlying conditions that already affect the dog can increase the risk of permanent damage or death.  

Chances of survival improve with early recognition of heatstroke, intensive treatment and supportive care. However, patients that survive are at a greater risk of heatstroke again in the future.  

Prevention 

• Never leave your dog in a car unattended.   

• Avoid strenuous exercise in hot and humid weather.  

• Provide access to the shade while outside. 

• Offer frequent opportunities to drink water. 

• Avoid walks during the hottest time of the day. 

• Remain indoors during periods of extreme heat and humidity. 

Check out more of our summer safety tips for keeping your dog safe from heat-related illnesses.