How to Recognize Signs of Frostbite and Hypothermia in Dogs

Written by: Deb German

It’s important that you keep vigilant for signs of problems in cold weather.
Photo by Carrie, Lake Forest

Two conditions—frostbite and hypothermia in dogs—often join ranks, with extreme cold as a common denominator. Playing outdoors in the winter can be joyous for your dog, but overexposure to the elements increases his risk for potentially life-threatening problems, especially if he belongs to a vulnerable population. Older dogs can also suffer from additional cold-related issues. Read on to learn how to recognize the signs of frostbite and hypothermia in your pooch, and how to avoid this troublesome pair of problems.

What is frostbite in dogs?
Frostbite, also known as congelatio, is the injury or death of skin and other tissues resulting from prolonged exposure to freezing or subfreezing temperatures. The tips of a dog’s ears, his tail, his scrotum, and his toes are the body parts most vulnerable to frostbite.

In brutally cold temperatures, the human body restricts blood flow to its extremities and instead conserves and maintains heat in its core; this is precisely what happens in dogs, too. The tissue that loses heat via blood flow can become as cold as the surrounding air, and will die if it freezes. Frostbite occurs when a dog is exposed to cold for a very long time, but can also happen if he is immersed in a cold body of water.

What are the symptoms of frostbite in a dog?
Frostbite may take days to appear, especially in small or non-weight-bearing areas of the dog. Look for:

• Pale tissue or skin that turns bluish-white or gray from constricted blood flow
• Skin that is cold to the touch or brittle
• Ice that has formed around the affected area
• Redness, swelling, and possibly blisters or ulcers
• In extreme frostbite, blackened or dead skin, called necrosis
• The sloughing off of dead tissue over a period of days to weeks
• Pus accompanied by a foul smell, signs of a secondary bacterial infection

As blood flow is restored to a frostbitten area, it will become very painful for the dog.

Is my dog at risk of frostbite?
If your dog is unused to the cold, is small, short-haired, or has a thin coat, he’s vulnerable; ditto a dog who has heart disease or diabetes, who takes certain meds, or has other medical conditions where blood flow to his extremities decreases. Dogs who live outside are extremely susceptible to frostbite; it can even occur on dogs with thick hair.

How do I treat my dog’s frostbite?
Your vet should thoroughly examine your dog, and in serious cases may order bloodwork and urine tests to assess possible internal organ damage. You can start the treatment while you wait to see the vet:

• Get him to a warm, dry area.
• If he is hypothermic, deal with that first (see below).
• Don’t try to warm the frostbitten area unless you know you can keep it warm.
• Carefully warm the affected area with water heated to about 104°F – 108°F and no warmer: you should be able to comfortably put your hand in the water. Apply warm compresses or soak the affected area in a bowl of the warmed water.
• Pat the area dry and head to the vet, but keep your dog wrapped in a warmed towel or blanket on the way.
• Do not rub the frostbitten area, do not apply dry heat (for example a heating pad or hair dryer), and do not give pain meds, which can be toxic to your dog—the vet will tell you what to do.

After thoroughly examining your dog, the vet may:

• Give your dog meds to address pain from thawing tissue
• Administer warmed intravenous fluids or give your dog a warm water enema
• Give him antibiotics to address a secondary infection if necrosis is suspected

Will my dog recover from frostbite?
In a mild case, his frostbite may resolve with little permanent damage; in a more severe case his frostbite may leave him disfigured. But in extreme cases of frostbite the damaged area will require surgical removal or amputation.

What is hypothermia in dogs?
If your dog has suffered frostbite, there is a good chance he’s also hypothermic. Hypothermia (from the Greek hypo, meaning under, and therme, meaning heat) is a dangerous drop in the dog’s body temperature; it leads to complications and can be fatal, even for a dog with a thick coat.

Causes of hypothermia include:

• Prolonged exposure to cold temperatures
• Wet skin and fur
• Immersion in water for too long
• Shock
• Anaesthesia (note: most dog owners will never have to deal with anaesthesia-related hypothermia because the attending vet will)
• Disease of the hypothalamus
• Hypothyroidism

When a dog’s body temperature dips too low, he can’t achieve a normal temperature without treatment. The decrease in oxygenated blood flow during hypothermia can injure the dog’s tissues; the extent of injury depends on how cold the body becomes and for how long.

What are the symptoms of hypothermia in dogs?
Signs of hypothermia in dogs occur along a continuum as follows:

• Mild Hypothermia (body temperature between 90° and 99°F): weakness, shivering, lack of mental alertness
• Moderate Hypothermia (body temperature between 82° and 90°F): muscle stiffness, low blood pressure, a stupor-like state, and slow, shallow breathing
• Severe Hypothermia (body temperature lower than 82°F): fixed and dilated pupils, inaudible heartbeat, difficulty breathing, and coma

A dog’s normal body temperature is between 101 and 102.5°F.

Look for signs of hypothermia in your dog if he’s been outside in the cold for a long time, especially if his coat or skin has gotten wet. If he’s been immersed in icy water, check him immediately. Shock can also bring on hypothermia; observe your dog’s gums—if they are pale or white and your dog is lethargic, get him to a vet immediately. Pay close attention to your dog’s symptoms: hypothermia can lead to death.

Is my dog at risk of hypothermia?
Newborns are vulnerable in even a normal environment. Small dog breeds and puppies are more prone to rapid surface loss of body heat and therefore at higher risk of hypothermia, as are geriatric dogs.

How do I treat my dog’s hypothermia?
First, quickly warm some blankets in the dryer or on a radiator. Then:

• Wrap your dog in the warm blankets.
• Wrap a hot water bottle and place it against your dog’s belly. Warning: never place a heat source directly against your dog’s skin.
• If your dog is conscious, offer him warm fluids to drink.

Check his temperature every ten minutes via rectal or ear thermometer; remove the hot water bottle once his temperature reaches 100°F, but keep him in a warm room. If his temperature falls below 98°F, get him to the vet, stat.

In severe cases of hypothermia the vet may measure your dog’s temperature with a rectal or esophageal probe; irregularities in heartbeat and breathing will be noted, and an electrocardiogram (ECG) may be indicated. Your vet may begin invasive warming treatments, for example giving a warm water enema and warm intravenous fluids. Some dogs require oxygen via face mask and intravenous blood volume support. The vet will also examine your dog for frostbite.

How can I keep my dog from getting frostbite or hypothermia?
The key to prevention for both conditions is warmth: avoid exposing your dog to extreme cold for long stretches, especially if he is in a high-risk population—if he’s very young or very old, has low body fat, or struggles with hypothalamic disease or hypothyroidism. When you must take him outdoors in the cold, put him in a dog coat or jacket  and shoes. And give him a warm, dry place to retreat from the elements if he lives outside. Common sense is the best strategy: enjoy the wintry outdoors with your beloved companion, but come inside from the cold when it’s time. Has your dog ever suffered from frostbite or hypothermia? We’d love to hear your story in the comments.