Heat Stroke in French Bulldogs
It’s the time of year again – the hot, lazy days of summer that we wait for all year.   But it’s also the time of year when higher outside temperatures can lead to a dangerous condition in some dogs:  heatstroke.   Heat stroke, also known as heat prostration or hyperthermia, is defined as an extreme elevation of core body temperature, usually above 40oC, caused by high ambient temperatures, or by other conditions that cause the body temperature to rise dramatically.  It is a potentially fatal condition in brachycephalic dogs such as French Bulldogs.
At this time of year, when daytime highs often reach the 30’s and the humidex approaches 40oC, heatstroke can develop rapidly in dogs that are outside.   The most common way this condition develops quickly is when a dog is left in a car without adequate ventilation on a summer day, something none of us would knowingly do.  But heat stroke could also develop in a dog left in a yard with inadequate shade or water, or even one out for a walk during one of our summer heat waves.
To prevent heat stroke:
•    ensure your dog always has access to cool drinking water and shade when outside
•     avoid exercising and walking your dog during the hotter parts of the day.  An early morning or late evening walk is best, especially on those hot, humid days in July and August
•    never leave your dog in a car during even warm days – the temperature inside a car even on a relatively cool (22oC) day can reach 45oC in less than an hour if your car is in the sun
In a recent study of dogs suffering from heat stroke and presented to a veterinary teaching hospital, a large percentage [25%] were brachycephalic breeds, including French Bulldogs, and in 50% of the cases the condition was fatal.   Careful monitoring of your Frenchie on warm days will alert you to signs that heat stroke may be developing.
Signs of heat stroke may include:
•    excessive panting, restlessness and anxiety
•    drooling from the mouth and/or nose
•    wobbliness/unsteady gait
•    bright red-purple/blue gums (due to lack of oxygen)
What can you do if you suspect your dog may be suffering from heat stroke?  Quick action at home and prompt transportation of your dog to your veterinarian will give your dog the best chance of making it through an episode of heat stroke with no dire consequences.
When possible do the following:
•    move your dog from the hot situation (e.g. car, yard) to a cooler area
•    direct a cooling fan onto him/her
•    if possible, take and record the rectal temperature
•    begin to cool the body by placing cool, wet towels over the neck, axillae (‘arm pits’), groin and ears.  DO NOT use cold water or ice for cooling (this may actually delay cooling of the core body temperature, as very cold water will shrink superficial blood vessels and reduce the loss of heat from the body)
•    bring your dog to your veterinarian or local emergency veterinary clinic as soon as possible
Although it is beneficial to have your dog drink cool water, do not try to force water into the mouth using a syringe or other method, especially if he/she is not fully alert.  And do not leave your dog unattended for any length of time.
Although heat stroke is a severe condition that can cause multiple organ failure and even death, it can be prevented.  And if necessary it can be treated successfully in many cases.  However, it is important to note that even dogs that survive are at greater risk for developing heat stroke in the future due to damage caused to the body’s thermoregulatory center.   So let’s do all we can to prevent heat stroke from ever developing in any of our dogs, and have a happy and safe summer with your Frenchie!

Dr. Chris Murfin, DVM
Kingsdale Animal Hospital