The “Dog Days of Summer” Aren’t Always So Canine Friendly!
Now that the thermometer is regularly topping out over 90 degrees (even here in the frozen tundra of Michigan!) it is a good time to review the prevention of heat stroke in our dogs and cats. Remember that dogs and cats do not sweat from their skin–they only have sweat glands on their paw pads and the tips of their noses. So panting when they are warm is the only really effective method they have of cooling their body. When the body temperature rises, the blood supply to the mouth and tongue increases…the panting cools the body by passing air over the blood filled tissue. Plus, a lot of evaporation occurs from the mouth further
aiding in the cooling process.
Heat stress and heat stroke occur when the body’s ability to cool the blood is not sufficient to keep the body temperature within safe limits. This can lead to multi-system organ failure at temperatures greater than 106 degrees. Dogs and cats have higher normal body temperatures than humans (101-102.5 degrees is typically normal). Body temperatures greater than 109 degrees are extremely
critical. When the ambient temperatures are high enough, any pet is at risk. But things like dehydration, illnesses, older pets and certain breed conformations (the Brachycephalic or “Smooshed Faced Pets”) dramatically increase the risk of over heating and heat stroke.
One of the easiest ways for a pet to overheat is by being left alone in a parked car (even for a perceived short period of time). Overheating can occur quite rapidly. The temperature inside a parked car (even with the windows cracked) can climb to over 100 degrees within a matter of minutes!! (If the ambient temperature is over 90 degrees–in as little as 5-10 minutes and if the ambient temperature is “only” 70-80 degrees–as little as 20 minutes can lead to heat stress). Temperatures as high as 120 degrees have been reported inside closed cars! Your pet’s panting increases the humidity inside of the car, further worsening the situation. To drive home this point (if you are not already convinced)…try sitting in your parked car some time this summer and see how long you last (even with the windows cracked)!!!
The next most common scenario leading to a heat stroke emergency is an afternoon of fun and sun out at the local park (or beach/backyard/etc). Many dogs love to play so much that they will walk, jog or chase a frisbee much longer than they should just for the sheer joy of being with you, their owner. It is our responsibility to monitor their activity, take breaks and offer plenty of fresh, cool water to keep the summer enjoyment from turning tragic.
Initial signs of heat stroke are: excessive panting, drooling, restlessness and confusion. This can progress rapidly to delirious behavior and loss of consciousness or seizures and death. Microscopically what is happening is a combination of four things: Thermal Damage (or Heat Damage); Cellular Necrosis (Cell Death); Hypoxemia (Lack of Oxygen) and Breakdown of Proteins in the Body.
How does this look to our Vital Organ Systems? The Nervous System will experience nerve cell damage as well as cerebral edema (brain swelling). The Cardiovascular System will go into hypovolemic shock and the heart can begin to beat irregularly (arrhythmias) and experience muscle damage. The Gastrointestinal Tract can develop ulcerations leading to GI bleeding and absorption of bacteria and toxins into the blood stream. The Liver will experience cellular damage. The Kidneys can go into Acute Renal Failure. The
Circulatory (Blood) System can see a dramatic loss of Platelets or a Clotting Disorder known as Disseminated Intravascular Coagulopathy. Finally the Musculoskeletal System will experience muscle cell damage.
Once signs of Heat Stroke develop it is essential to begin to bring your pet’s body temperature down and seek immediate Veterinary Care. Wetting your pet down with cool (NOT cold) water and then wrapping them in towels soaked in cool water should be the extent of your home emergency care….you should be on your way to your Veterinarian’s Office (or the local Veterinary Emergency Clinic) ASAP. If your pet is able to drink small amounts of cool water you may offer that on the car ride to the hospital. The cool water will help to begin the cooling processes that your Veterinarian will continue at the hospital….cold water will cause vasoconstriction at the surface of the skin which will actually work to trap the heat within the body. Once at the hospital, the Veterinary Health Care Team will begin Emergency Stabilization procedures which will likely include: further cooling of the body, IV fluids and monitoring of all of the vital organ systems.
If caught early enough many cases of heat stroke are treatable without any lasting effects, but unfortunately we see way too many Heat Stroke Deaths during the summer months….especially when they can be prevented with a little planning and a little extra caution with our furry friends. Just imagine how you would react to the weather if you were outdoors in July or August wearing your winter parka and it may help to put you in the mindset of taking some of the extra needed precautions to keep your pets safe and sound.