Heat Strokes in Dogs: What They Are, How to Identify Heat Exhaustion, and How to Respond

by Tasha Phillips, M.S.

July is upon us, and the summer heat has officially arrived! With temperatures reaching well above 90 degrees Fahrenheit, it’s important to remember the proper care for your pet in extreme heat.

Some areas, such as Texas, are experiencing heat up to 101°F. Summer is an awesome time to go out with your pet and enjoy these long days, so let's make sure we are doing it safely.

Heat strokes, by nature, are a severe overheating in the body. As core temperatures rise, the body’s cooling systems begin to break down. The body is unable to cool itself through panting or sweating, which leads to a range of downstream effects.

As a dog’s body temperature begins to rise above 101.5°F, it is called hyperthermia. As their temperature rises to 105°F, the dog may be suffering from heat stroke.

Dogs typically cool themselves down through blood vessel dilation and panting. Panting allows the dog to move air across membranes of the tongue, nasal passages, and lungs. As air moves across these tissues, it carries heat away from the body.

They can also cool themselves through vasodilation, or expansion of blood vessels in the body. Blood vessels bring blood closer to the surface of the skin to cool down – especially in areas like the ears and face.

What Happens During a Canine Heat Stroke?

1. Cooling Systems Fail: A dog’s body cannot keep up with extreme temperature demands and is unable to cool itself quickly enough. Because dogs are unable to sweat through their skin like us, higher temperatures can quickly overtake them.

2. Vasodilation: To cool off, blood is directed away from the core of the body to extremities like the ears, face, and feet. Dilation of vessels assists to carry blood there faster as the heart rate increases.

3. Organ Failure: Blood carries oxygen and important nutrients that vital organs such as the brain, liver, kidneys, and intestines require. Lack of blood flow leads to slow failure of these organs as well as muscle death.

4. Brain Damage: As blood is directed away, the brain is not receiving enough oxygen or glucose to sustain itself, which can lead to permanent brain damage. Dogs can experience seizures, and this ultimately leads to death.

5. Muscle Breakdown: Rhabdomyolysis is the rapid breakdown of muscle cells, releasing electrolytes and large proteins into the bloodstream. This can cause irregular heart rhythm and seizures.

   Another downstream effect from this protein release is kidney damage. Kidneys are the filter of the body and remove things from the blood through urine. These large proteins clog up the kidneys leading to damage and failure.

What Are the Early Signs of Overheating in Dogs?

Panting

While panting is normal, be sure to notice if your dog is straining to catch their breath, breathing with a wide-open mouth, and the color of their mucous membranes and tongue.

A bright red and swollen tongue may be a sign that your dog is overheating. If your dog begins to pant with their tongue very outstretched and to the side this is an early sign of overheating. Start taking action to cool your pet down.

Fast and Irregular Heartbeat

As the dog’s body temperature rises, their heart is attempting to increase the rate that blood moves throughout the body. Dehydration also makes the blood thicker, making the heart work harder to move it to the surface of the body to cool off.

Excessive Drooling

A rise in body temperature increases saliva production from the surface of the mouth and tongue.

Collapse and Fainting

As blood is quickly moved to extremities to cool off, vital organs are being neglected.

What to Do If You Believe Your Dog Is Overheating

1. Carry or walk your dog to a shaded area or air-conditioned environment.

2. Pour water across the dog’s feet and abdomen. Avoid wetting their coat, as water droplets can get trapped between the skin and fur and retain heat.

3. Offer cool water, but do not force your dog to drink. If your dog in unconscious, wet their tongue with cool water. Do not use ice cubes, as this can lead to a too sudden drop in temperate. It is important to cool them slowly.

4. Begin transport to an emergency veterinary center for care. Time is critical here. The sooner treatment is initiated both by you and medical staff, the better the outcome for your pet.

Tips to Safely Have Fun in the Summer Sun

Now that we’ve covered what heat strokes are and how to treat them, let’s cover the most important part. Avoid them all together!

1. The number one cause of heat stroke in dogs is being left in hot cars. Under no circumstances should you leave any pet (or person, for that matter) in a closed car, even if it’s only for a few minutes and the windows are down.

   On hot days, inside temperatures can reach 102°F in as little as 5 minutes. After 30 minutes, temperatures can reach 120°F. This is fatal for pets and children.

2. Always be aware of temperatures when taking your dog out. Ideally, you should limit their outdoor time to early mornings and late evenings to avoid the midday sun.

3. Walk dogs in grass and avoid pavement or sand.

4. Get that summer hair cut for long hair dogs!

5. Provide shady areas with cooling aids. A kiddie pool with cool water is a go to for many pet parents. You can also provide a sprinkler or misting hose to keep the water moving. You can also give frozen treats like ice cubes, frozen fruits, or frozen dog treats.

6. Go for adventures near water. Temperatures tend to be a little cooler near rivers where water is moving. This allows your dog to take a dip and a drink when out in the sun.

At the end of the day, your dog’s number one concern is having as much fun as possible. They will often run and play until collapse, so it is your job to enforce play breaks and regular hydration.

Have fun and stay safe!

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Tasha Nelson Phillips is a veterinary assistant and researcher. She began her work in veterinary medicine in 2014 at a small practice in East Tennessee. She has a B.S. in Biology as well as a Master’s degree in Microbiology from East Tennessee State University. Her undergraduate and graduate research focused on Lavengel®, exploring its efficacy and mechanism of action against common bacterial species.

Tasha’s interests focus on natural antimicrobial options and exploring novel compounds to combat antibiotic resistance. She continues to work in small animal emergency and critical care medicine. She spends her free time with her husband and three furry babies in their East Tennessee home.