Heat Exhaustion or Heat stroke is a serious condition for dogs. This can occur in cats as well, but usually only on rare occasions when a cat is caught in a dryer and dried with clothes. We’ll focus on dogs for this particular problem.

Heat stroke can occur if a dog’s body temperature is consistently elevated above 103 degrees for an extended period of time. Normal body temperature for dogs is between 99.5 degrees to 103 degrees. If they are exposed to sustained heat that they are not acclimated to or on an extremely hot day in the summer, they are at risk for heat stroke. It is mainly a seasonal problem, occurring in the summer months. Dogs that have an increased chance of getting it are obese, have brachycephalic heads (short, squished faces), or have longer, and/or darker hair.

There are several risk factors to be aware of. Exposure to high environmental temperatures can result from being in a confined space. Examples are being left or trapped in a car in the middle of summer or being caught in the clothes dryer when it is running (Cats!). Vigorous exercise on a very hot day can also lead to heat stroke. Dogs with respiratory problems such as laryngeal paralysis, collapsing trachea, or brachycephalic breeds (due to an abnormal upper respiratory system) are at risk as well. Lastly, dogs with heart disease are more likely to develop this problem.

There are many recognizable signs that this can be occurring. The first one is usually excessive panting after heat exposure. Extreme lethargy or collapse may happen soon after. Any mental change can be a sign, for example, not coming when being called, or being less responsive in general. Excessive drooling, glazed eyes, and lack of coordination can be seen as well.

The results of heat stroke can range from mild to devastating, depending on the case. It can potentially affect many of the body’s systemic organs. Effects on the lungs, heart, blood, kidneys and neurological tissue are possible. If a dog is obtunded (extremely unaware of its surroundings) or in a coma, it is less likely to survive. The mild cases may have signs such as lethargy and dark urine due to the breakdown of muscle tissue. When severe cases occur, the dog is less responsive or comatose, very lethargic, panting excessively, or maybe making unusual respiratory sounds. In all of these situations, treatment is needed as soon as possible. In extreme cases, even with treatment, dogs can pass away or be euthanized due to the damage done to the body.

Prevention is simple. Having your dog not be too exposed to heat for an extended length of time or avoiding prolonged physical activity in warm ambient temperatures are the ways to avoid this problem. Breeds such as Bulldogs (English and French), “Bully” types, Pugs, Boxers, and Shih Tzus are more at risk. This is due to the inefficient upper respiratory systems they are born with, making it harder for their bodies to cool down when panting. Limiting their activity in the heat is strongly recommended.

If you recognize signs of heat stroke in your dog, I recommend as follows:

1. Move your dog to a cooler area, indoors in air conditioning or to shade if still outside.

2. Find a thermometer to determine the rectal temperature of the dog. Again, the normal temperature can range from 99.5 to 103 degrees. Anything above 103 degrees can be a concern, especially temperatures of 104 to 106 degrees.

3. Call a veterinarian: Our office, or an emergency veterinary center. This way we can advise you on the next steps to take (likely to bring in the dog immediately) so the staff will be able to prepare for the treatment of the animal when it arrives.

4. Cooling down the dog may be necessary prior to traveling to the vet. If it can drink water, give it cool, fresh water. If it is not able to drink, wetting the tongue may help. Also, placing cool wet towels on the body may help. Overcooling the body can be a problem, however. Bringing the temperature down too low or cooling too fast can make the dog could go into shock, leading to additional complications.

In conclusion: The key to avoiding heat stroke is prevention! Having Rover get some exercise in the summer is fine but be careful on extremely hot days by limiting the activity. Also, be careful to not leave a dog in an automobile because temperatures in a hot car during the summer can get up to 120 degrees. The aforementioned breeds and dogs with respiratory problems are not recommended to have any rigorous play in the summer heat. Their bodies can heat up very quickly due to the lack of an effective cooling system, it is better if they are rested during the warmer months. Recognizing the signs of this problem can be the difference in the treatment outcome for your dog. If you suspect any signs of heat stroke, please give us a call immediately, and we will advise you on what to do next.

Dr. Jaime Kozelka
St. Francis Hospital for Animals