Frostbite in dogs: symptoms, first aid and treatment

Overview

Frostbite differs from hypothermia, in which the whole body's core temperature becomes dangerously low. Prolonged cold exposure can cause both local frostbite and life-threatening hypothermia. Frostbite can also affect the muzzle or a male dog's scrotal skin.

Superficial frostbite is classified as first- or second-degree injury. Deep frostbite is classified as third- or fourth-degree injury. In the most severe, fourth-degree injury, damage can reach muscle and bone. A change that looks mild initially may therefore prove deep later. Mild frostbite may heal with little permanent damage, but severe injury can alter tissue permanently.

Causes

Reduced circulation and freezing

When the environmental temperature falls below 0°C, blood vessels near the skin constrict. The body directs blood away from peripheral tissues towards vital internal organs to preserve core temperature. Severe or prolonged cold can reduce peripheral circulation to dangerously low levels. Poor blood flow combined with cold can lead to freezing and severe tissue damage.

Ice crystals forming in tissue and cellular water are part of the injury mechanism. Prolonged direct contact with snow or ice can increase frostbite risk. Wind and wet conditions increase the danger.

Cold can injure tissue without freezing it

Not all cold injuries involve actual tissue freezing. Exposure for over 12 hours to cold temperatures above freezing can also damage peripheral skin. This injury can cause marked redness, pain and itching. In wet conditions, skin may also swell and become waterlogged.

Risk factors

A small dog loses heat more easily than a large dog. Puppies have immature temperature regulation and little insulating fat. Older, thin or chronically ill dogs may also become cold more readily. Heart disease or diabetes may increase frostbite risk if they impair peripheral circulation.

A short, thin coat provides less protection than a dense double coat. A dog arriving from a warm climate or suddenly exposed to freezing weather is not yet acclimatised. A wet dog is particularly vulnerable to frostbite of the paws, ears and tail. Even thick-coated Arctic dogs can suffer cold injury to their pads.

Typical symptoms

Signs may appear after a delay, particularly in small or non-weight-bearing areas such as ear and tail tips. Thawing tissue may become red and painful because of inflammation.

• Skin becomes pale, grey or bluish.
• The affected area feels cold and brittle.
• Skin may feel hard and numb.
• Your dog resents touch or licks and bites the painful area.
• The frostbitten area swells.
• Blisters or ulcers develop.
• In severe injury, skin starts blackening or dying.

Paw frostbite can cause varying degrees of lameness. Even before tissue injury, a cold dog may lift their paws, shiver or refuse to move.

Complications and consequences

Severely frostbitten tissue may die and slough off over days or weeks. Ear-tip tissue loss can remain permanent after necrosis. Bacterial infection may develop in dying tissue, causing pus and an unpleasant smell. Severe injury may require surgical removal of dead tissue or a body part.

Refreezing of a thawed area can deepen tissue damage. Concurrent severe hypothermia can cause arrhythmias and kidney or heart damage. Untreated severe hypothermia can be fatal.

Diagnosis at the vet

Exposure history and skin assessment

Diagnosis usually uses a history of cold exposure and clinical examination. Exposure duration and severity determine which further tests are needed. Your vet also assesses possible shock or whole-body hypothermia.

Superficially frostbitten skin may look grey-white and waxy. Blisters can occur even with second-degree frostbite. Deeply frostbitten tissue may be black and fragile. Tissue viability may require repeated assessment before a surgical decision.

Assessing general condition and possible infection

After prolonged or very severe cold exposure, blood and urine tests can look for internal organ damage. Tests in a severely hypothermic dog may include a blood count, organ values, electrolytes and clotting. Continuous ECG can monitor heart rhythm. Monitoring blood pressure, urine output and consciousness helps assess circulation during warming.

An infected frostbite wound can be cultured to guide antibiotic selection. If an ear ulcer's cause is unclear, other possibilities include vasculitis, a bite injury or a clotting disorder.

If a hypothermic dog has metabolic abnormalities or their condition changes, blood glucose, electrolytes and lactate may be monitored every 4–8 hours. Investigating another cause of apparently dead ear tissue may require a skin biopsy.

Treatment

First aid and preventing further damage

Move your dog somewhere warm and dry as soon as possible. Dry a wet dog and cover their body with warm, dry towels or blankets. If hypothermia is present, whole-body cooling is treated before warming local frostbite. Keep your dog warm during transport to the vet too.

Do not massage or rub frostbitten skin because this can worsen damage. A hot hairdryer or a heating pad directly on the skin is unsuitable for warming frostbite. Do not start thawing somewhere the tissue could refreeze before reaching shelter.

Controlled warming and pain relief

Your vet chooses warming, pain relief and tissue protection according to the injury and your dog's condition. Local frostbite can be warmed with warm, moist towels for 15–20 minutes. With this method, towels are replaced every 5 minutes. Afterwards, the skin is gently patted dry. Thawing can be very painful, so prescribed pain relief may be needed.

Severe hypothermia may require hospital-based active warming and warmed intravenous fluids. Core temperature is monitored during warming because it may initially continue falling. This afterdrop partly results from cold peripheral blood returning to the central circulation.

A severely hypothermic dog may need supplemental oxygen to reduce arrhythmia risk. An unconscious dog's airway is protected, and warmed, humidified oxygen may be given. Warming the whole body too rapidly can cause sudden blood vessel dilation and falling blood pressure. Circulation is therefore monitored alongside temperature.

Non-freezing cold injury is treated by moving the dog into a warm room and slowly warming the tissue under a blanket or towel.

Blisters, bandages and surgery

A loose bandage may protect frostbitten tissue from further injury. Keep your dog calm and restrict movement to protect damaged tissue. A protective collar can prevent licking or biting. Your vet may drain a large clear-fluid blister aseptically. Blood-filled blisters are left intact.

Routine preventive antibiotics are not recommended for frostbite alone. If needed, an antibiotic for an infected wound is selected using culture. Severe injury may require removal of dead tissue. Surgery is usually delayed until the boundary between living and dead tissue can be assessed.

Caring for broken skin

If frostbite leaves an open or necrotic wound, it needs wound care too. Flushing removes dirt and reduces bacteria within tissue. Dead tissue and foreign material are surgically removed if needed. An infected wound may be managed open until infection is controlled and closure becomes possible.

Prevention

Shorten cold-weather outings according to your dog's tolerance. There is no single safe sub-zero temperature limit for every dog. Dry wet fur and paws on returning indoors to reduce heat loss. A suitable coat can provide extra warmth for a small, older or thin-coated dog.

Well-fitting boots protect paws from cold. An ear-covering snood or suitable head covering can help protect vulnerable ears. Do not leave your dog waiting in a cold car or outdoors while shopping. A dog kept outdoors needs insulated, windproof shelter and dry bedding.

A sick or injured dog needs a calm recovery area with suitable conditions. Bring a kennelled dog indoors if a protective collar prevents access to the kennel.

Avoid unnecessarily close clipping in winter so the coat retains its insulating effect. Remove snowballs between the paws after coming inside because they can cause discomfort. Clean road salt from the paws too, as it can irritate skin.

Important for dog owners

Watch how your dog moves during walks and return to warmth if they shiver, lift their paws or refuse to continue. Check the ears and a male dog's scrotal skin too: boots protect only the paws. Do not delay care for suspected frostbite until skin turns black.

Avoid rubbing affected skin even when drying it. Do not give painkillers on your own initiative before veterinary assessment. Over the following days, watch for darkening skin, pus and an unpleasant smell. Protect the area from licking and provide a quiet place to recover.

Stopping shivering does not show recovery: a severely cold dog may stop shivering completely.

Frequently asked questions

Can a thick-coated dog get frostbite?

A dense double coat protects better than a thin coat. Nevertheless, even an Arctic dog's pads can suffer cold injury. Prolonged exposure, wetness and wind increase danger, so monitor the paws, ears and tail of thick-coated dogs too.

Can frostbite be seen immediately after a walk?

Skin may immediately be pale, grey, bluish or cold. However, the full extent of damage may become visible only over several days. Small ear- and tail-tip injuries can be particularly easy to miss initially.

Should I rub a frostbitten area to warm it?

Do not massage or rub frostbitten tissue because this can cause further injury. Move your dog somewhere dry and warm. Do not start local warming outdoors if the area could freeze again. Take your dog for veterinary assessment without delay.

Does frostbite always need antibiotics or surgery?

Frostbite alone does not usually require preventive antibiotics. If a wound becomes infected, culture can guide medication selection. Mild injury may heal with little permanent damage, but severe necrosis may require removal of dead tissue or the affected body part.

Is frostbite the same as hypothermia?

In frostbite, local tissue freezes and becomes damaged. In hypothermia, the whole body's core temperature falls dangerously low. Prolonged cold exposure can cause both problems simultaneously. If both are present, hypothermia is treated before warming the local frostbite injury.