Heat stroke can kill a dog in a very short period of time, if the condition is not treated aggressively. The goals of treating heat stroke are to establish an open airway and provide oxygen to improve gas exchange and allow for additional dissipation of heat, cool the dog off, lower the dog’s body temperature to the normal range and identify and resolve the underlying cause of overheating. This may be as simple as removing the dog from the source of environmental heat. Unfortunately, this is not always easy to do.
There are some things that owners can do to increase a dog’s chances of surviving heat stroke. Emergency measures to cool the dog must begin immediately. The dog should be taken out of any enclosed or hot environment and moved to an air-conditioned setting if possible. The owner should take the dog’s rectal temperature every 15 minutes or so, once she recognizes the signs of heat stroke and has moved the dog to a cool place. If the dog’s temperature is greater than 104 degrees Fahrenheit, the owner should cool it before trying to get it to a veterinarian. She should still call the closest veterinary clinic to alert them to the situation and ask what steps to take before and while transporting the dog to the hospital. The owner can aid cooling by wetting the dog with cool water from a garden hose or spray bottle, or by immersing it in a tub of cool water for a minute or two. The dog should not be immersed in ice or ice-cold water. Cooling an overheated dog too quickly can cause its blood vessels to constrict (peripheral vasoconstriction), which will slow down heat dissipation. The damp dog can be placed in front of an electric fan, if one is available. Cold packs applied to the groin area and to the paw pads can accelerate the temperature drop; isopropyl (rubbing) alcohol can be applied to the foot pads, under the front armpits (axilla) and on the groin and flanks to enhance evaporative cooling.
Once the dog’s temperature has decreased to 103 degrees Fahrenheit or lower, the animal should be dried off, kept at normal room temperature and taken to a veterinarian. The medical team will take steps to normalize the dog’s core body temperature. Many animals will be hospitalized and receive intensive inpatient care for at least several days. Room temperature fluids and electrolytes may be administered intravenously at shock rates, depending upon the dog’s condition. Oxygen can be given either through a mask, in an oxygen cage or using a nasal catheter. In severe cases, where the dog is obtunded or comatose, the veterinarian may intubate it to ensure that it has an open airway and is receiving sufficient oxygen directly. The dog’s activity will be restricted, and normally it won’t be fed until its temperature and vital signs are stable.
A number of potentially dangerous medical conditions can occur after heat stroke, including heart abnormalities, kidney failure, liver failure, bone marrow problems, laryngeal edema, cerebral edema, disseminated intravascular coagulation (DIC), seizures and spontaneous bleeding, among others. These can happen from hours to days after the inciting event. There are no specific drugs to treat heat stroke. However, some medications can help manage the complications associated with the condition, which the dog’s owner can discuss with the veterinarian. Patients should be monitored around the clock during the first few days after the cooling-down process. Again, early recognition and aggressive treatment of heat stroke are critical to a successful outcome.
The prognosis for dogs with heat stroke is highly variable and ranges from good to grave, depending on how quickly the condition is caught and treated. Dogs that recover from heat stroke usually suffer no long-term side effects. However, once a dog develops neurological signs, such as seizures or coma, the prognosis is much more guarded.