What causes a burn?
A burn is a type of injury to the skin. The three most common causes of burns include:
- Thermal burn. Caused by heat; common causes include fire, smoke, or steam
- Mechanical burn. Caused by friction, such as when rope or a carpet travels over skin
- Chemical burn. Caused by contact with a chemical or chemical fumes; common causes include acids, drain cleaners (lye), gasoline, and paint thinners
How are burns classified?
Burns are classified based on how many layers of skin are affected, or how deeply the skin is damaged.
A superficial burn (first-degree burn) involves only the outermost layer of the skin, the epidermis. These burns result in pain and redness, with no other visible signs of injury. Superficial burns typically heal quickly (in a few days), with minimal care.
A partial-thickness burn (second-degree burn) involves both the epidermis and the outer layers of the dermis. Partial thickness burns cause redness, swelling, blistering and drainage. They make take a couple of weeks to heal and are at risk of infection.
A full-thickness burn (third-degree burn) involves the epidermis, all layers of the dermis, and the subcutaneous tissues. These burns can result in the loss of pain sensation in the affected area as they destroy nerve endings. Affected tissue can be white, red, or black. Eventually the formation of an eschar (a hard piece of dried secretions and dead tissue) will overly the burn. The eschar may require removal to prevent infection. Once all dead tissue has been removed (a process called debridement) surgical repair with skin flaps or grafting may be needed. Healing is prolonged, and risk of infection is high. These burns will lead to permanent scarring.
The damage to deeper tissues may not be immediately obvious, as it can take time for the overlying skin to die. This means the severity of the burn may be initially underestimated, especially in thermal burns.
"Burns are classified based on how many layers of skin are affected, or how deeply the skin is damaged."
What tests will my veterinarian perform if my pet has a burn?
Mild burns can often be treated symptomatically, without any need for diagnostic testing.
In the case of more severe burns, however, your veterinarian may perform several diagnostic tests to guide treatment decisions and determine your dog’s prognosis.
Bloodwork (including a complete blood cell count, serum biochemistry, and electrolytes) is often performed in pets with severe burns. This bloodwork allows your veterinarian to assess your dog’s internal organ function, blood protein levels, and electrolyte levels. Protein levels often fall in pets with severe burns; if protein levels become critically low, your veterinarian will need to administer supplemental proteins. Electrolyte abnormalities are also common in pets with severe tissue destruction; these abnormalities may also need to be corrected.
Your veterinarian will also monitor your dog’s blood pressure. The body loses a significant amount of fluid through burns and blood pressure monitoring will help your veterinarian determine whether this fluid loss needs to be corrected.
If burns appear to be infected, your veterinarian may recommend a culture and sensitivity. This test allows the lab to grow a culture of the bacteria that are infecting your dog’s wound, then test multiple antibiotics against the cultured bacteria. A culture and sensitivity can determine the best (most effective) antibiotics for your dog, while also helping to ensure that the antibiotics you use do not contribute to a resistant infection.
How are burns treated?
Burn treatment depends upon the severity of the burn.
Intravenous (IV) fluids are used as needed in burn patients to prevent dehydration. They are often required in patients with partial-thickness or full-thickness burns, especially if these burns are widespread. When the skin is disrupted by a burn, large amounts of bodily fluids can escape through the wound; IV fluids prevent dehydration. Blood or plasma transfusions may be required for severe fluid or protein loss.
Burn patients also require aggressive pain control. Your pet may receive a combination of injectable and/or oral pain medications to keep him comfortable while recovering. Antibiotics are often needed in second and third degree burns to prevent infections. These may be oral, injectable, or topical.
"Antibiotics are often needed in second and third degree burns to prevent infections."
Partial-thickness or full-thickness burns are often covered with bandages or dressings, which must be changed daily. These bandage changes must be performed in as sterile of a manner as possible, in order to decrease the likelihood of introducing infection. Your veterinarian will recommend appropriate topical treatments to use with bandaging; topical treatments are often changed during the healing process, because different treatments are appropriate at differing stages of healing.
Your dog may also require additional supportive care, depending on the severity of the burns. If your dog is unable to stand, he should be turned every 4 hours to prevent bed sores. If your dog is unwilling to eat, he will be hand-fed, syringe fed or have a feeding tube placed. Healing from burns requires a lot of energy; it is important that the pet receives adequate nutrition.
For third degree burns multiple surgical procedures may be necessary for debridement and surgical closure with skin flaps or grafting if needed.
What is the prognosis for burns?
In general, superficial burns heal readily, even without treatment. Partial-thickness burns also typically have a good prognosis, with appropriate veterinary care, unless the burns are widespread.
Full-thickness burns, however, are much more taxing on an animal and can lead to death. The prognosis for full-thickness burns is guarded, depending on how much of the body is involved and the patient’s overall health status. Treatment must be rapid and intensive if they are to recover, and recovery can take many months.