Is your best walking/running companion your dog?  If so, there are some safety precautions to consider concerning your canine exercise partner before the two of you head out into the heat this summer.  First, it is important to realize that your dog cannot cool its body as efficiently as can you.  Its fur interferes with heat conduction to the environment.  Your dog also cannot rely on sweating as a means by which to remove heat because it has a limited number of sweat glands (located on the pads of its paws).  Your dog removes body heat through panting.  As your dog fatigues from the exercise, this mechanism of regulating its body temperature becomes more difficult, putting it at risk for developing heat exhaustion.

     According to Dr. Douglas Brooks of Gasow Veterinary Hospital in Birmingham, Michigan, there are certain breeds of dogs who are most susceptible to developing heat exhaustion.  Short-muzzled breeds such as boxers, bull dogs, and pugs will have the greatest trouble dissipating heat as will canines with heavy coats.  Dogs that are overweight, de-conditioned, or old may have difficulty as well. 

     To reduce your dog's risk for developing heat exhaustion, Dr. Brooks recommends taking your dog for walks/runs in the early morning or evening hours when temperatures are cooler (this will also reduce your risk for developing a heat illness).  Make sure to bring water with you for both you and your dog.  Allowing your dog to take frequent water/rest breaks, preferably in the shade, will also lower its risk of overheating.  

     Dr. Brooks suggests that you take your dog for fewer and shorter walks when the temperature is above 80 degrees Fahrenheit (following this recommendation for your dog will benefit and protect you from the heat as well).  To protect your dog, you should also have an understanding that there is a heat gradient between the ground and the air.  The average sized dog falls right in middle of this gradient, about 18 inches above the ground.  This gradient is a result of surfaces, such as asphalt, retaining heat from the sun.  Therefore, air temperature for the dog is hotter than it is for you, putting it at a greater risk for overheating.

     While exercising with your dog, you will want to pay close attention to how it is acting.  Dr. Brooks states that if your dog starts to pant heavily, appears lethargic, or is having difficulty standing up, these could be an indication that it is developing heat exhaustion.  Other signs to look for in your dog include excessive salivating followed by a dry mouth, pale/gray gums, rapid heartbeat, vomiting, diarrhea, and/or seizures.  If you suspect heat exhaustion, Dr. Brooks recommends placing your dog in a tub of water to facilitate lowering its core body temperature.  In severe cases, a trip to your vet may be warranted.

     Another concern to be aware of is the temperature of the surface on which you and your dog will be walking or running.  Your shoes protect your feet from the heat of the cement; but, your dog's paw pads will have direct contact with the hot pavement, putting them at risk for getting burned.  Feel the pavement before you start your run.  If it is too hot, consider running on the grass or wait until temperatures have cooled.

     A run in the sun with your favorite canine companion this summer should be enjoyable.  Make sure it doesn't lead to a heat illness in either one of you by following the tips above.  For more information on how to protect yourself while exercising in the summer heat, refer to my earlier posts "Keeping Water on Board: An Exerciser's Guide to Staying Hydrated During the Summer Months" and "Tips to Prevent Your Child from Overheating at Summer Camp."

Note: Before beginning an exercise program or increasing the intensity level of a current routine, a physician's approval should be obtained, especially for older adults and those at risk for or who currently have chronic health conditions.

Resources:

June 23, 2009 Phone Interview: Dr. Douglas Brooks of the Gasow Veterinary Hosptial (www.gasowvet.com).

ACSM Fit Society Page Summer 2005, "Dog Safety During Hot Summer Runs," p.4. Angle, C.

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