Hypothermia is a medical term used to describe a body temperature that is below normal. The most common cause of hypothermia is prolonged exposure to cold environmental temperatures. If left untreated, affected animals may develop signs of frostbite or may even die.

In addition to prolonged exposure to cold weather, impaired ability to regulate body temperature can also lead to hypothermia. This is most often associated with newborn puppies and older debilitated dogs. Certain illnesses, such as hypothyroidism, and impaired behavioral responses can also be a factor in the body's inability to maintain adequate temperature.

Normal body temperature for dogs is 100.5 to 102.5 degrees Fahrenheit. Signs of hypothermia range from mild to severe, depending on the severity of the low body temperature.

What to Watch For

Depression

Lethargy

Weakness

Shivering

Muscle stiffness

Low heart and respiratory rates

Stupor

Difficulty breathing

Fixed and dilated pupils

Coma

Diagnosis

Recording a low body temperature with a thermometer will confirm the diagnosis of hypothermia. Additional diagnostics may be carried out to identify an underlying cause.

Baseline diagnostics to include a complete blood count, biochemical profile, and urinalysis are generally within normal limits.

A full coagulation (clotting) profile may reveal some abnormalities.

Thyroid function tests may confirm hypothyroidism.

An electrocardiogram may show an array of arrhythmias (abnormal heart rhythms)

Treatment

It is important to monitor the patient's temperature closely during the treatment period.

Mild hypothermia can be treated with blankets and insulation.

Moderate hypothermia should be treated with external rewarming heat sources such as heating pads. Protective layers should always exist between the external heat source and the individual in order to prevent skin burns.

Severe hypothermia often needs to be treated aggressively. Core warming techniques include warm water enemas and stomach lavage (washing out), warm intravenous fluid therapy and warmed air.

Intravenous fluid and electrolyte support, in addition to oxygen supplementation, may be indicated in some cases.

Electrocardiograms and repeat blood pressure evaluations are important in monitoring these patients.

Home Care and Prevention

Sick or hypoglycemic (low blood sugar) newborns can become markedly hypothermic in a normal environment. It is important to keep these individuals warm, and possibly even monitor their rectal temperature.

If you are suspicious that your dog may be suffering from hypothermia, contact your veterinarian at once. In the interim, use blankets and insulation to start the rewarming process.

Preventing hypothermia is key. Do not leave your dog outside in freezing temperature for any length of time without access to shelter and warmth.