Canine Heatstroke: Signs, Symptoms And Treatment Of Heatstroke in Dogs

Heatstroke is a serious and potentially life-threatening situation. Dogs left untended in cars are the most likely victims.

We all know it is not safe to leave an animal in a closed car when the outside temperature is extremely warm.

However, even in temperatures as mild as 70-75°F, the temperature inside of a closed car can increase as much as 40° or more in one hour!

Canine Heatstroke: Signs, Symptoms And Treatment Of Heatstroke in Dogs

Besides the car scenario, there are other situations in which heatstroke becomes more likely for our dogs as well.

Conditions under which your dog can suffer from heatstroke include:

hot and/or humid days without the availability of adequate shade and/or water (outdoors or indoors)
heavy exercise on a hot and/or humid day
brachycephalic (short-nosed) breeds are more likely to develop hyperthermia (an elevated temperature). Their anatomy hampers the ability to pant and cool down effectively.
obesity affects the airways. This makes panting less effective.
other diseases that hamper the airway. These conditions can also alter the effectiveness of the panting mechanism
forced heat, such as a hairdryer

Symptoms and signs of heatstroke in dogs

Early symptoms seen with heatstroke include restlessness and excessive panting. The respiratory rate and heart rate will increase. Excessive drooling may also occur.

Vomiting and/or diarrhea may occur. Dehydration and depression will occur as the symptoms worsen.

As the situation progresses, the gums may turn brick red in color or even purple or blue as oxygen saturation declines.

Your dog may have difficulty breathing and may appear to be gasping. He will become weak and may stagger. Seizures may occur and the animal may become totally comatose. Petechial hemorrhages, small red areas that resemble bruising, may appear. As the dog nears death, the temperature may actually decrease to below normal.

A body temperature higher than 105°F is cause for alarm.

It is important to remember that elevated temperature can have many different causes. Heatstroke is only one of those.

However, you can draw clues in the environment or the recent history of the dog. Such information increases the probability of a diagnosis of heatstroke. For instance, a dog locked in a car that has symptoms consistent with heatstroke is likely suffering from heatstroke rather than another disease.

Treatment of heatstroke in dogs

Any dog suffering from heatstroke needs veterinary attention as soon as possible.

However, you can take measures to begin cooling the dog before transport. It is important not to lower the body temperature of the dog or cat too much or too quickly. You can place cool, wet towels around or over your dog. You can also place them between the dog’s legs–both front and rear. Placing cool water on the ears and paws may help cool the dog also.

Naturally, the dog should be removed from the environment which caused the heatstroke. If possible, direct a fan toward the dog or cat.

Do not use ice or extremely cold water to cool a dog or cat suffering from heatstroke. Doing so may actually make the condition worse.

Cooling the dog is part of treating for heatstroke, However, other intervention might be necessary to save the dog’s life. Rapid evaluation and treatment at a veterinary facility is usually necessary.

Effects of heatstroke

Heatstroke affects all body systems and causes thermal damage to numerous tissues.

The kidneys are damaged, leading to acute kidney failure.
The gastrointestinal tract is damaged and may lead to bacterial translocation from the intestinal tract into the bloodstream.
Damage to the liver and to the heart can occur due to thermal damage.
There may be swelling within the brain and infarctions that cause further brain damage.
Clotting deficits may occur, leading to bleeding abnormalities.

Treatment for heat stroke will vary depending on the condition of the animal, but intravenous fluid support is usually necessary.

Blood transfusions may be required. Oxygen therapy may be necessary for animals suffering from respiratory depression. Cerebral swelling (swelling within the brain) may require specialized medications, such as mannitol to reduce the swelling. Antibiotics may be necessary if there has been damage to the gastrointestinal tract to combat sepsis caused by bacterial translocation. Other therapies may be required.

Severely affected may not survive despite best attempts at resuscitation.

Preventing heatstroke in dogs

In most cases, heatstroke is preventable by taking some simple precautions.

Do not leave animals caged, tied or otherwise confined outside without adequate shade and water. At very high temperature, animals should be moved indoors rather than being kept outside for prolonged periods of time.
Do not leave animals in closed compartments exposed to the sun, such as a closed car.
Increased caution should be used with animals that are obese, have respiratory difficulties, are geriatric or are otherwise unhealthy.
Be aware that some animals will lie in a sunny window long enough to become subject to heatstroke. Restrict access to these areas if necessary by closing blinds or draperies.
Provide adequate water for animals that are performing strenuous exercises in warm temperatures.

Be aware that dogs performing arduous physical activities require more water–sometimes as much as twice the amount or more than a dog at rest.

Further reading:
Heatstroke in dogs
Heatstroke in dogs: Part 2