All Pets Veterinary Clinic


While people are smart enough to know the risks of hot temperatures and take the
necessary precautions to avoid becoming overheated, we sometimes forget to consider our
animals needs. Heat stroke can be a life threatening condition for anyone--animals
included. This article will focus on the risk factors for heat stoke as well as the
signs, treatment, and prevention of heat stroke in animals.

Animal risk factors. Animals are at an increased risk for heat stroke if they
are very old or very young, overweight, not used to being outside for long periods of
time, not conditioned for prolonged exercise, or if they have heart, respiratory, or
certain neurological diseases. Animals that have had problems with heat stroke
previously are at risk for recurrence. In addition, animals on certain types of
medications, including diuretics like Lasix, are at an increased risk for heat stroke.

Environmental risk factors. Certain environmental conditions also increase the
odds of heat stroke happening. Obviously, the higher the temperature the greater the risk.
Relative humidity also plays a critical role. With a higher relative humidity lower
temperatures can predispose to heat stroke. For example, if it were 85 degrees outside,
there would be a much higher risk for heat stroke if the humidity were 75% versus if the
humidity were only 20%. Lack of shade, lack of water, and poor ventilation are other
environmental factors that can increase the risk for heat stroke.

Signs. Animals with heat stroke will generally have a high body temperature.
Normal body temperature for many of the common domestic species is about 100-102 degrees.
In heat stroke, animals can experience body temperatures as great as 109 degrees.
Temperatures at this level are life threatening. Brain damage can occur at temperatures
above 106 degrees. Increased panting, bright red mucus membranes, such as the gums,
weakness, increased heart rate, lethargy, stupor, seizures, coma, vomiting, and diarrhea
can occur. Liver, kidney, and heart problems can all result as well.

Treatment. Since heat stroke can be fatal, quick medical attention is critical.
The main goal of treatment for heat stroke is to reduce the body temperature to a more
appropriate level while avoiding over cooling. Body temperature can be decreased by
placing towels that have been soaked in cold water on the animal, moving the animal to a
cooler environment, using fans to help cool the animal, etc. IV fluids and other
medications may be necessary to help stabilize the animal as well. Frequent temperature
checks are necessary to assure that the body temperature does not fall below normal.

Prevention. As with many things, prevention is your best defense against heat
stroke. When it is hot out or when there is a high relative humidity, allow animals that
are not used to hot temperatures to remain outside for short periods of time only. If
an animal must be outside for long periods of time, assure that there is adequate shade
and water available. Avoid intense exercise during the hottest part of the day. And
most importantly, monitor animals frequently if they are outside for long periods of
time, especially if they have any of the risk factors for heat stroke.

The information provided is for educational purposes only and is not
intended to take the place of your regular veterinarian. Please do not hesitate
to contact your regular veterinarian if you have questions regarding your pet.

Karen Blakeley, DVM, MPH
14 December 2002