Heat Stroke – Hyperthermia

Categories: Dog Health, Dog Safety

By Laura Yurchak

One thing that gets my adrenalin going is seeing a dog in a car during the warm weather months or someone jogging with their dog in 90° weather. People don’t realize how quickly heat stroke can occur.

Heat Stroke (Hyperthermia) can kill your dog within 10 minutes under the right conditions. Heat stroke in dogs occurs when the dog’s body is absorbing more heat than it can release.

Dogs release heat primarily by panting and through their foot pads and noses. A dog’s normal temperature is between 100 – 102 degrees. Once a dog’s temperature elevates over 106 degrees, the dog’s body is unable to regulate normal functions. When this happens, damage to the dog’s muscles, organs, and metabolic processes can occur.

Heat stroke in dogs is a potentially life threatening condition that requires immediate medical treatment. Once you see signs of heat stroke, you have very little time before serious damage or even death can occur.

Cars act like ovens when the sun is shining on them. The Weather Channel states that leaving a gap open in the windows has little effect because the heat buildup occurs mainly from radiant energy from the hot metal of the car. The interior color of the car, dark being most troublesome, influences the heat buildup. Even a dog’s body heat (expired air in the dog’s breath is 102 degrees and has 100% humidity!) will act like a heater inside an enclosed space. Leaving windows open slightly at the top surely helps IF there is a good amount of breeze coming through. Even in the shade, and especially in humid conditions, dogs need to inhale air cooler than their normal body temperature. In fact, even 80 degree air temperatures can be dangerous. Some dogs can recover fully from heat stroke if it is caught early enough. Others suffer permanent organ damage and require lifelong treatment. Some die.

Signs of Heat Stroke

Physical symptoms include:
  • Increased rectal temperature
    • Over 104° requires action
    • Over 106° is a dire emergency
  • Vigorous/ uncontrollable panting
  • Labored breathing
  • Dark red gums
  • Tacky or dry mucus membranes (specifically the gums)
  • Salivating, thick saliva or foaming at the mouth
  • Vomiting
  • Bloody diarrhea
  • Dehydration
  • Lying down and unwilling (or unable) to get up
  • Trembling, dizziness, disorientation
  • Wide-eyed
  •  Shock
Extreme symptoms:
  • Collapse
  • Loss of consciousness, coma
  • Seizures
  • Death

Preventing Heat Stroke

  • Leave your dog at home on warm days.
  • Avoid vigorous exercise.
  • Keep is shaded and well ventilated area when outside.
  • Keep fresh cool water available at all times.
  • Dogs more sensitive to heat stroke are:
    • Obese dogs
    • Older dogs
    • Very young dogs
    • Dogs with heart conditions
    • Brachycephalic (short-nosed) dogs
    • Those that moved from cooler, less humid climate

What to do if You Suspect Heat Stroke

  • Move your dog out of the heat, away from the sun
  • Check the rectal temperature
    • Over over 104° requires action
    • Over 106° is a dire emergency)
  • Submerse in luke warm (NOT COLD) water
  • Wet belly, head, neck and legs
  • Can apply wet rags to head, neck and body
  • Run Cool water over tongue & mouth
  • Apply rubbing alcohol to paw pads
  • STOP COOLING when body temp reaches 103°
  • Contact your veterinarian immediately
DO NOT use ice or very cold water! Extreme cold can cause the blood vessels to constrict, preventing the body from cooling and actually causing the internal temperature to rise. Overcooling can cause hypothermia, causing new problems.
Outside Temp Time in Car Inside Car Temp
90 degrees 10 mins 113 degrees
90 degrees 20 mins 120 degrees
90 degrees 30 mins 133 degrees