Hypothermia in Dogs

Key Takeaways

Hypothermia is defined as lower than normal body temperature.

• Normal body temperature of dogs is 101-102°F (38.3-39°C)

• Body temps of below 98°F (36.7°C) are considered hypothermic

• Hypothermia can be classified as primary or secondary

• Primary hypothermia results from environmental exposure to cold; secondary hypothermia results from the body’s failure to generate enough heat for itself due to injury or underlying disease

• Diagnosis involves taking a rectal or core temperature

• Mild to moderate hypothermia is relatively easily treated with basic rewarming strategies

• More severe cases are life-threatening and require more intensive treatment

• Treatment of underlying causes is essential to a good prognosis

A Closer Look: What is Hypothermia in Dogs?

Hypothermia is classified according to severity:

• Mild hypothermia: 90 – 99°F (32.2-37.2°C)

• Moderate hypothermia: 82-90°F (27.7-37.2°C)

• Severe hypothermia: any temperature less than 82°F (27.7°C)

Both primary and secondary hypothermia are dangerous and, in particular, secondary hypothermia is very concerning. It may be a sign of serious illness such as diabetes, heart failure, shock, or serious infection, among others.

Hypothermia is especially a problem in small dogs, and can contribute to shock and organ failure.

Hypothermia is uncommon in dogs. It is very important that hypothermic dogs receive medical attention right away, as it is potentially life-threatening.

Risk Factors

Generally speaking, symptoms worsen as the dog’s body temperature drops.

During mild to moderate hypothermia, symptoms include:

• Shivering

• Muscle stiffness

• Weakness

• Lethargy

• Difficulty walking

• Pale gums

• Cool body surfaces

• Increased breathing rate

As hypothermia progresses in severity, symptoms shift and include:

• Shivering stops

• Collapse

• Dilated pupils

• Low and irregular breathing rates

• Loss of consciousness

Dogs left outdoors in extreme weather and those with pre-existing serious internal conditions are more at risk of developing hypothermia.

Possible Causes

Primary hypothermia is caused by exposure to cold environmental temperatures.

Secondary hypothermia has many potential causes, including:

• Kidney disease/failure

• Heart failure

• Diabetes mellitus

• Bleeding due to injury

• Anesthesia and other medications

• Hypoadrenocorticism (Addison’s Disease)

• Toxins, including anticoagulant rodenticides, blue-green algae, xylitol, zinc, bromethalin, tick paralysis

• Pneumonia

• Viral infections, such as rabies, distemper, parvovirus

• Bacterial infections, such as Salmonellosis and plague

• Sepsis

• A variety of parasitic diseases, including babesiosis

Main Symptoms

Symptoms of hypothermia include:

• Weakness

• Shivering

• Collapse

• Poor response to visual, auditory or touch stimuli

• Loss of consciousness

Testing and Diagnosis

Diagnosis of hypothermia involves taking a rectal or core body temperature.

To identify treatable underlying conditions, as well as to assess any resultant damage, the dog may also require full physical exam, bloodwork, urinalysis, and diagnostic imaging. Additional diagnostics are particularly important in cases of suspected secondary hypothermia.

Steps to Recovery

Once hypothermia is identified, the first step is to immediately start rewarming measures. The method(s) used depend on the severity of the condition. Mild hypothermia can usually be treated with blankets and moving to a warmer location. More severe cases may require additional external heat sources, warmed IV fluids, warm enemas, and warm abdominal, stomach, chest, or urinary bladder lavage.

Mild hypothermia is relatively easily treated, and dogs usually make a full recovery. In cases of moderate to severe hypothermia, there is the potential for damage to the internal organs. Prognosis in these cases varies depending on the severity of damage.

Prevention

Primary hypothermia can be prevented by:

• Keeping dogs inside during very cold temperatures

• Monitoring dogs while out in the cold

Healthy dogs are more cold tolerant than humans, but dogs who are acting cold or uncomfortable should be brought in.

Secondary hypothermia prevention involves keeping up with routine wellness checks so chronic illnesses are identified early and treated before they progress to the stage where they cause secondary hypothermia. Drugs and other toxins should be kept out of reach of animals. Hypothermia is not contagious, but some of the underlying causes are, such as viral, bacterial, and parasitic infections.

Is Hypothermia Common in Dogs?

Hypothermia is not common in dogs, but is more common in colder climates. Hypothermia is more common in small dogs, old dogs, and sick dogs.

Typical Treatment

• Warming blankets

• Moving to warmer environment

• Internal warming methods

• Diagnosis and treatment of secondary conditions