by Ashley Bentley, DVM
Heat stroke can have rapid onset and is a life-threatening issue for the canine patient. Any dog left in a closed-windowed car on a hot day can develop life-threatening hyperthermia in a matter of minutes.
Additionally, dogs that are exposed to hot outdoor temperatures without access to rest, cool/shaded areas, and water can quickly show signs of heat stroke.
No dog is immune to risk of heat stroke, but certain dogs are at increased risk. Bulldogs and other brachycephalic (short-nosed) breeds, obese patients, or those with laryngeal paralysis or other respiratory conditions may not be able to ventilate and cool themselves as effectively as other dogs.
Signs of heat stroke that you as the owner may recognize in your dog include excessive panting, collapse, trouble breathing, rapid heart rate, disorientation/dull mentation (thinking), or GI upset. If any of these signs are noted or heat stroke is suspected, you need to seek immediate veterinary attention. Active cooling measures should be started en route to the veterinary hospital:
- Move the dog out of the sunny, warm area into a shaded or air-conditioned environment.
- Obtain a rectal temperature on your dog if you can. Heat stroked dogs can commonly present to the emergency room with temperatures as
high as 106-108 F. Such severe elevation in body temperature can cause subsequent bleeding disorders, multi-organ failure, and sepsis.
- Place a cool, damp towel over the dog's back and place him in front of a fan or air conditioning vent in the car. You can also offer (but don't force) fresh, cool water.
- Do NOT dump ice water all over the dog. This will just cause constriction of blood vessels and complication getting the body temperature down to a safer range.
- Active cooling measures should be stopped once the dog's temperature is 103.0 F.
Once at the veterinary hospital, an intravenous catheter may be placed to provide IV fluids to further assist with cooling. Diagnostics such as bloodwork to assess organ function, clotting function, and perfusion (blood flow to tissue and organs) will also likely be checked. Heat stroke patients are often hospitalized for a few days to continue fluids therapy and other medications to prevent and/or address complications of the hyperthermia.
Prompt recognition of heat stroke can lead to faster stabilization and better outcomes for the dog. When in doubt, have the dog evaluated on an emergency basis.