What is heat stroke? Heat stroke is a form of hyperthermia (high body temp) that occurs when a dog’s heat-dissipating mechanisms of their body cannot accommodate extreme temperatures. These mechanisms to dissipate heat include panting and sweating…heat is removed from the body by the evaporation of sweat. Dogs do not sweat the way horses or people do so they rely mainly on panting and dilation of the peripheral blood vessels to remove excess heat. Body temperatures in the dog that exceed 106 degrees F without evidence of an infection suggest hyperthermia (a normal dog temperature can vary from 100 to 102.6 degrees F…a fever is when their temp is greater than 103 degrees F). The critical temperature for our dogs when they are hyperthermic is 109 degrees F. This is the temperature that is associated with heat stroke!
When a dog reaches the 109 degrees F mark, thermal damage occurs causing cellular death leading to multiple organ (liver, brain, kidney, gastrointestinal, muscle) failure…and ultimately death results!
Signs to look for while in the field include excessive panting, high rectal body temperature, excessive salivation, brick-red gums, higher than normal heart rates (it’s a good idea to know what your dog’s normal body temp and heart rate is), difficulty breathing, bloody diarrhea or bloody vomitus, dizziness, disorientation, muscle tremors or weakness, changes in behavior…to name a few.
Factors that can influence the severity of heat stroke include age, obesity, long hair coat, poor acclimation, poor conditioning, underlying heart or lung disease, dehydration, and most importantly a previous history of heat-related disease. Dogs that have had a previous heat related injury are much more prone to having a 2nd episode because their heat regulatory center in the brain is most likely already damaged.
What can you do to immediately begin treatment in the field while on the way to the nearest hospital? Great question! Spray your dog with water or immerse their entire body prior to traveling to the nearest hospital. Use a cooling fan if at all possible. You can soak the dog’s feet and groin/armpit area with rubbing (isopropyl) alcohol to aid in convection or removal of heat. Monitor the dog’s temperature constantly…once they hit 103 degrees F, stop all cooling procedures because they can become hypothermic very suddenly. DO NOT use ice on these dogs because it causes the blood vessels to constrict with will impede heat removal. Be very careful in giving them both food and water once they’re in heat stroke as it may cause severe gastrointestinal distress. Move your dog ASAP to the nearest hospital for further treatments!
Some things I do with with my own dogs is condition early in the morning when the sun is not directly over head. I work them in an area with lots of available ground water for dunking and drinking. Make sure you force breaks or periods of rest on your dogs! Make them rest and rehydrate them often! Condition, condition, and condition them!