Heatstroke in Dogs

Key takeaways

Heatstroke is a type of heat related illness, and is always a life-threatening emergency. The normal body temperature range for dogs is 101.5°F(38.6°C). Heat stroke in dogs occurs when body temperatures reach 105-110°F(40.5-43.3°C).

  • Extremely high body temperature can lead to organ shut down and internal system failure
  • Heat-related illnesses occur in sequence; signs of heat exhaustion occur prior to heatstroke
  • Common symptoms are severe vomiting and diarrhea (often bloody), collapse, seizures, and loss of consciousness, and pale or blue gums
  • Heatstroke is most likely to occur in extreme temperatures, and is more likely in cases of overexertion, sudden temperature shifts, certain medical conditions, surrounding environment, and other predisposing factors
  • Diagnosis depends on a physical exam, medical history, and the results of several tests to determine the extent and location of organ and internal system damage
  • Treatment can include transfusions, antibiotics, and other medications
  • Prognosis depends on the response to treatment
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A closer look: Heatstroke in Dogs

It is the direct result of thermal injury to the organs and systems within a dog’s body. Taking steps to avoid heatstroke is a priority for every pet parent.

In cases where organ failure has occurred, symptoms differ depending on what system has been damaged.

Animals left in extreme heat are at risk of life threatening heatstroke. Left untreated, heatstroke can lead to coma and death.

Risk factors

Heatstroke occurs most commonly in warm environmental conditions, and can be prevented when pet parents are aware of the danger and respond to early warning signs. Heatstroke is life-threatening, and warrants immediate medical attention.

Many factors contribute to heatstroke, but concern for it grows when:

  • Ambient temperatures exceed 65°F (18°C)
  • Ambient relative humidity is high (above 65%)
  • Access to shade and ventilation are limited
  • During increased activity or exercise
  • If there is an underlying predisposing condition

Certain underlying conditions put a dog at higher risk for heatstroke. Pets should be monitored more closely during exercise, especially in hot and humid conditions.

Dogs who are unacclimated to the heat are also at increased risk, as are dogs who engage in physical activity beyond their fitness level. Golden retrievers and Labrador retrievers have been shown to be predisposed to heatstroke, although the cause is unknown.

Possible causes

Heatstroke is caused anytime a dog’s ability to get rid of body heat is outpaced by the environmental conditions. This can occur passively in hot environments, especially when the humidity is high (non-exertional heatstroke), or actively when the dog exercises (exertional heatstroke). Exertional heatstroke is more common during the summer, but can occur in cooler temperatures. Many occurrences of heatstroke result when dogs are left without adequate ventilation in hot vehicles.

Testing and diagnosis

Diagnosis begins with determining medical history and performing a physical examination, which includes a measurement of body temperature.

Possible tests include, but are not limited to:

  • Hemogram or complete blood count(CBC)
  • Blood serum chemistry profile
  • Coagulation testing
  • Chest X-rays
  • Electrocardiogram

Steps to Recovery

Treatment is determined case by case based on the symptoms displayed. General treatment begins with first aid efforts by pet parents to wet down and cool the pet on the way to veterinary care. These are short term actions a pet owner should take while on the way to professional care:

  • Remove pet from hot environment
  • Make water available to drink, but don't force them
  • Wet down the pet, targeting heat exchange areas; groin, armpits, back of neck, ear flaps, and paws
  • Speed up cooling with a fan, open car windows, or turn on air conditioning

Depending on the results of the diagnostic tests, other treatments may be added to the cooling efforts including:

  • IV fluids
  • Oxygen therapy
  • Ventilatory support
  • Antibiotics
  • Plasma transfusions
  • Gastroprotectants (medication to protect the stomach and intestinal lining)
  • Blood pressure medications

Severe symptoms that don’t improve with cooling efforts and treatment for shock indicate a very poor prognosis.

Recovery is based on the severity of heat stroke, how the patient responds to treatment, and if there are secondary conditions or complications.


Heat stroke is not contagious. It is prevented by monitoring a pet for signs of heat exhaustion and taking corrective action before symptoms develop into a life threatening condition. Ensuring that dogs are always in well ventilated areas with access to shade and water can help prevent heat stroke.

Is Heatstroke in Dogs common?

Heat stroke is common, but can be prevented if pet owners are aware of how dangerous it can be and what steps can be taken to stop it.

Typical Treatment

  • Cooling
  • IV fluids
  • Oxygen therapy
  • Gastroprotectants