Virginia Simpson and Chance

Heat Stroke

by Elizabeth Gigis, DVM, West Chester Veterinary Center

The summer is definitely upon us! This means vacations, trips to the pool, and other fun summer activities for most of us. It can, however, be a dangerous time for your pet if precautions are not taken. One major cause of health issues for pets during the summer is heat related injuries. Heat stroke is a condition where a dog’s body temperature rises above 105. A normal body temperature for a dog is less than 102.5. Heat stroke can occur in indoor dogs not acclimated to extreme heat when outside for only 10-15 minutes. The humidity is also a complicating factor. A type of dog that is over-represented is the brachycephalic or “short-faced” dog, such as pugs and bulldogs. These dogs have a smaller diameter airway, so much more work is required for a short faced dog to pass the same amount of air to get cool. As a result, these dogs get anxious, and the airways become inflamed or swollen. This leads to a vicious cycle of increased anxiety and more swelling.

Dogs that are “outdoor dogs” during the summer should always have access to shade. A children’s wading pool is a good idea also, and can be purchased at most major retailers for less than twenty dollars. Remember to change the water regularly. It is important to note that a dog left in a car (even if the windows are cracked) can develop heatstroke, often in only five minutes.

It is very important for you to be aware of how your dog has been outside, and always monitor him for early signs of heat injury during these summer months. Let’s review some of the common signs of heatstroke. Dogs pass air quickly over the tongue through panting. Saliva is evaporated from the tongue as air passes across, and this cools the blood circulating through the tongue. This blood is circulated to the rest of the body. If this mechanism is not sufficient for cooling, the body temperature will rise and you will begin to see the beginnings of a heat stroke. First, the dog will increase his panting, and then begin to salivate. He may lie down and refuse to get up. His mucous membranes or gums will begin to look “muddy” or bluish purple, instead of pink. The pet may also vomit or have diarrhea. In severe cases, dogs can lose consciousness and have seizures as the brain overheats. It is important to note that heatstroke can cause severe damage to all major internal organs, including the liver, kidneys, heart, lungs and brain. Heat stroke also causes problems with the clotting factors inside the dog’s blood stream, a severe and life-threatening condition called “DIC”. Even if your dog recovers from the initial heat injury, he can be left with a lifelong condition that may require treatment.

If you suspect your dog may have heatstroke, it’s important to institute some basic first aid procedures, and then take him to a veterinarian immediately. Bring your dog inside and immediately begin to spray him off with cool water. Also apply rubbing alcohol to his paw pads. Do not apply ice packs to the skin or hair, as this can cause blood vessels in the skin to constrict, moving the blood away from the skin, and prevents cooling. At your veterinarian’s office, your dog will likely be treated with IV fluids, oxygen therapy and other medications as needed depending on the severity of the heat injury. A heat stroke can have a mortality rate of up to fifty percent even if treated appropriately. Early treatment is critical to success and has a direct impact on your dogs outcome. Of course, prevention is the best cure!