What is frostbite?
Frostbite is damage caused to skin and other tissues due to extreme cold. When the environmental temperature drops below 32°F (0°C), blood vessels close to the skin start to narrow or constrict. This constriction of blood vessels helps to preserve core body temperature by diverting blood toward the core and away from the cooler parts of the body.
In extreme cold, or when the body is exposed to cold for long periods, this protective mechanism can reduce blood flow in some areas of the body to critically low levels, especially the extremities (e.g., paws, ears, and tail). The combination of cold temperatures and reduced blood flow can allow the tissues to freeze, causing severe tissue injury. Frostbite is most likely to happen in body parts farthest from the heart and in tissues with a lot of exposed surface area.
Where is a dog more likely to get frostbite?
The paws, ears, and tail are the most common tissues to be affected. If a dog is wet or damp, these areas are more vulnerable to frostbite.
What are the clinical signs of frostbite?
The clinical signs associated with frostbite include:
- discoloration of the affected area of skin - often pale, gray or bluish
- coldness and/or brittleness of the area when touched
- pain when you touch the body part(s)
- swelling of the affected area(s)
- licking or chewing of the affected area(s)
- blisters or skin ulcers
- areas of blackened or dead skin
As frostbitten tissues thaw, they may become red and painful due to inflammation. The clinical signs of frostbite may take several days to appear, especially if the affected area is small or if it occurs in non-weight-bearing areas, such as the tip of the tail or ears.
"As frostbitten tissues thaw, they may become red and painful due to inflammation."
Severely frostbitten areas will become necrotic or die. As the tissue starts to die, it changes to a dark blue to black color. Then, over a period of several days to weeks, it sloughs or falls off. During this time, pus may form, or the tissue may develop a foul smell, due to secondary bacterial infection.
Dogs with heart disease, diabetes mellitus, or other conditions that cause reduced blood flow to the extremities are at greater risk for frostbite.
How is frostbite diagnosed?
Diagnosis is usually based on medical history and physical examination. If your dog was exposed for a prolonged time or to extremely cold temperatures, blood and urine tests may be performed to look for damage to internal organs.
How is frostbite treated?
If you suspect your dog has frostbite, you should seek medical attention immediately. Interim first aid suggestions that you can begin include the following:
- Move your dog to a warm, dry area as quickly and safely as possible.
- If your dog is suffering from hypothermia or low core body temperature, treat the hypothermia first. Do this slowly by wrapping their body in warm dry towels or blankets and placing hot water bottles wrapped in towels near their body.
- Do not rub or massage the affected area.
- If you are outdoors, do not warm a frostbitten area unless you can keep it warm. Additional cold exposure or re-freezing will more severely injure the tissues.
- Do not use direct dry heat, such as a heating pad or hair dryer, to warm the affected area.
- You may carefully warm the affected area with warm (not hot) water. The recommended water temperature is 98.6°F to 113°F (37°C to 45°C). At this temperature, you should be able to comfortably place your hand in the water. If the water is too hot, you may cause more damage. You may apply warm water compresses or soak the affected area in a bowl of warm water.
- After you have warmed the area, pat dry carefully and thoroughly. Do not rub your dog with towels.
- While traveling to your veterinarian for further medical treatment, keep your dog warm by wrapping him in dry towels or blankets that have been warmed in the clothes dryer.
- Do not give any pain medication unless specifically instructed by your veterinarian. Many human pain relievers, including acetaminophen and aspirin, can be toxic to dogs.
How will my veterinarian treat frostbite?
Your veterinarian will examine your dog and treat any other conditions, especially systemic shock or hypothermia. Since the thawing tissues are extremely painful, your dog will probably be given pain medication. If tissue necrosis or death is suspected, antibiotics will be used to prevent secondary bacterial skin infection. In severe cases, some dogs will require amputation of the affected body part. Other therapies that are sometimes utilized include oclacitinib (Apoquel®), pentoxifylline, aloe vera, and hyperbaric oxygen therapy.
What is the prognosis for frostbite?
The prognosis for frostbite depends on the extent of your dog's injuries. Mild cases of frostbite usually resolve with little permanent damage, while more severe frostbite may result in permanent disfiguration or alteration of the affected tissues. In extreme cases, amputation or surgical removal of the necrotic (dead) tissues is required. Your veterinarian will discuss the appropriate diagnostic and treatment plan for your dog.
