Animal Hospital
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Hours of Operation:

Monday: 8:30 a.m.-7 p.m.
Tuesday: 8:30 a.m.-7 p.m.
Wednesday: 8:30 a.m.-5 p.m.
Thursday: 8:30 a.m.-7 p.m.
Friday: 8:30 a.m.-7 p.m.
Saturday: 8:30 a.m.-2 p.m.
Sunday: Closed

Heat stroke: keeping our pets cool this summer

The months of July and August are here and our pets feel the heat just like we do. Heat stroke, or malignant hyperthermia, refers to an acute (very sudden) rise in body temperature unrelated to infection. The hypothalamus is a portion of the brain responsible for setting the body's set point, or thermostat. This set point will increase in response to infection, or inflammation to increase the body temperature. This is called a fever.

A hyperthermic episode refers to a rise in body temperature without a change in the set point. Dogs and cats do not have the ability to sweat but mild hyperthermia can be compensated for by panting. However, if the body temperature rises too quickly and cannot compensate quickly enough, the results can be devastating, even fatal.

Dogs and cats normally have a higher body temperature than humans (it can vary from approximately 100 to 102.5 degrees Fahrenheit) and a fever of between 103 to 104.5 degrees is alarming, but not disturbing. Once a pet's body temperature gets above 106 degrees Fahrenheit we do start to get worried and everything that can be done to normalize body temperature should be done. If your pet's body temperature continues to rise above 106 degrees Fahrenheit permanent brain damage, heart damage and organ shutdown can occur.

We, as pet owners, are already aware that heat stroke will commonly occur when a pet is left in a hot room without circulation, a hot car, or overexercised on a very hot day but there are other underlying conditions unrelated to ambient temperature that should be discussed. Any underlying disease that can interfere with the normal panting process can lead to heat stroke.

Brachycephalic breeds (English bulldogs, pugs, Boston terriers, shar pei, shih tzus, Lhasa apsos, boxers) that have cute, squished-in faces are particularly vulnerable. Unfortunately, these breeds — or mixed breeds of this type — also have a lot of extra tissue in the back of their oral cavity right at their larynx, or voice box. The larynx not only allows our pets to communicate but is also the entrance to the airway. Anything that interferes with air moving through the larynx can also interfere with a pet's ability to regulate body temperature.

Laryngeal paralysis — a paralyzed voice box — can also lead to this same problem. The nerves and muscles that normally open the airway when a dog or cat becomes hot and pants heavily fail, leaving a much narrower space for air to flow through. The body temperature will continue to rise rather than normalize. It is also well known that seizures — no matter what the cause — lead to a rapidly elevated body temperature even on cool days and can cause heat stroke if not treated immediately.

How do I prevent heat stroke? Limit exercise on hot, humid days to mild to moderate impact and only in the early morning and early to mid evening. If your pet has an underlying disease — as described above — limit their time outside during the warmer months to just go to the bathroom. If the underlying disease is either surgically or medically correctable talk to your veterinarian as soon as possible.

What do I do in a crisis? A digital thermometer for your pet — and only your pet — should be part of a basic first aid kit. If you suspect heat stroke then take your pet's rectal temperature immediately. If the body temperature is above 106 degrees Fahrenheit then soak the pet with cool (but not cold) water or cover with towels soaked in cool water while you are preparing for transport. Once the towels get warm replace or re-soak them. Call your veterinarian's office to let them know you are coming or head directly to the nearest emergency clinic. If you are able to get the pet's temperature to below 103 degrees Fahrenheit before you leave, stop cooling and still monitor the temperature.

Dr. Kearns is a veterinarian with a special interest in emergency and critical care. He has been in practice for eight years.


Matthew Kearns, DVM