Pathophysiology of Thermal and Chemical Skin Injury
Burn wounds are categorized based on the depth of thermal penetration. First-degree burns affect the epidermis, causing redness and pain. Second-degree burns involve the dermis, characterized by vesicle formation and significant fluid weeping. Third-degree, or full-thickness burns, destroy the entire dermis and epidermis, often resulting in white, leather-like eschar that lacks sensation. A related condition that presents with skin loss but different underlying mechanics is a degloving injury, which clinicians must distinguish from burns during initial examination.
Systemic Sequelae of Extensive Burns
When large surface areas are affected, the patient enters a hypermetabolic state. The loss of dermal integrity causes significant transdermal water loss, leading to severe hypovolemia. Furthermore, if the injury involves exposure to power lines or household outlets, the pet may suffer from an electric shock, which often causes internal tissue damage even if surface burns appear minimal. Inhalation of combustion products is a high-risk complication requiring monitoring for pulmonary contusion and airway edema.
Diagnostic Approach to Burn Wound Management
Veterinarians initiate diagnosis with a thorough physical examination to assess the total body surface area (TBSA) affected. Laboratory diagnostics including a complete blood count, serum chemistry, and urinalysis are critical to assess for early-stage renal dysfunction and secondary infection. Because burns are highly painful and prone to secondary damage, clinicians will examine the ocular surfaces to rule out a corneal ulcer (traumatic) caused by flying debris or heat flares.
Surgical Debridement and Wound Bed Preparation
Once the patient is stabilized, the primary treatment goal is debridement—the surgical removal of necrotic or contaminated tissue to encourage healthy granulation. In severe cases, the wound may be covered with hydrogel or silver-impregnated dressings to combat potential bacterial biofilm formation. Owners should be aware that even small burns can hide deeper damage similar to that seen in a crush injury, requiring careful assessment of the underlying vasculature.
