Scalding

These types of burns are caused by contact with a hot liquid, and there is no singeing of the hair. Scaldings are caused by spills, splashing, immersion, or superheated steam. In animals, scalding may occur when fluid temperatures reach 120° Fahrenheit (48.8°C) (Sinclair et al., 2006; Merck & Miller, 2013).

In splash or spill burn injuries, the fluid cools as it flows down the side of the body. A burn is more severe where the liquid (fluid) had initial contact with the tissue surface, becoming more superficial as the fluid flows from the initial point of contact. Super-heated steam may cause severe scalding wounds. If the steam is inhaled, airway injury may result to the upper, lower, and deeper airways (DiMaio & DiMaio, 2001; Merck & Miller, 2013). This may cause edema in the larynx, resulting in occlusion of the airway and asphyxia. Intentional immersion burns are characterized by a straight line from the water level (Platt et al., 2006). This is dependent on the body part involved and the struggle or level of resistance from the animal victim. In the limbs this may develop in a stocking or glove distribution with a defined upper margin. A scald may be limited to the feet and the pads depending on the depth of foot immersion. In cats, the toes will retract with contact, protecting the areas between the pads (Merck & Miller, 2013). Gross findings of scald burns to the feet include loss of epithelium from the ventral pad surfaces with progressing drainage and darkening, normal non-erythematous areas between pads and toes, and erythematous skin with loss of hair and epidermis on the dorsal and lateral aspects of the toes or foot (Munro & Munro, 2008; Merck & Miller, 2013) (Figure 12.2).

Scalding burns over the dorsum may develop when water from an outdoor hose in hot climates is sprayed on an animal (Quist et ah, 2011). In many instances, this is accidental. However, if the burn is not recognized or addressed this may be grounds for animal abuse charges.

Cigarette Burns

Cigarette burn wounds, although not as well documented as in child abuse cases, do occur in animals (Munro & Thrushfield, 2001). An acute burn is red and circular, approximately, 0.5-1.0 cm in diameter. The burn may be wedge shaped if the cigarette was used at an oblique angle. A deliberate wound may be full thickness, creating a crater-like wound. An older burn wound can be circular and sunken, with thinly developed scar tissue on the surface. Accidental burns tend to be superficial and eccentric due to the brief contact with the hot ash (Munro & Thrushfield, 2001; Merck & Miller, 2013).

Figure 12.2 Scalding wounds: From hot water. (Photo courtesy R. Jesus.)

Solar Dermatitis

Solar injury or sunburns in conjunction with ultraviolet rays has been well documented in animals (Merck & Miller, 2013) in regions of diminished fur and light pigmentation. Thermal injury may also develop in dark pigmented areas from solar radiation. Darkened (black) skin can absorb 45% more solar radiation than light-colored areas of skin. Visible radiation penetrates the skin several millimeters and disseminates into thermal energy, further increasing the thermal burden (Merck & Miller, 2013). Histological findings demonstrate a full-thickness burn: epidermal adnexal necrosis, vascular necrosis, and subepidermal vesiculation (Merck & Miller, 2013). These types of cases present with burn lesions along the dorsum and may contain plaques and eschars. These wounds are often mistaken for animal cruelty in the form of a caustic agent applied to the animal’s back (Merck & Miller, 2013). Solar thermal necrosis is due to exposure to the direct sunlight. It usually occurs when an animal cannot obtain shelter (escape) from direct sunlight, specifically environmental circumstances or physical limitations (Merck & Miller, 2013). Animal abuse charges may result in instances where an animal is tied outside without adequate shade or shelter. Burn lesions from this type of circumstances (sun exposure) may not appear for days or up to 2 weeks.

Radiant Heat Burns

These are near-contact burns caused by heat waves generated by a hot surface such as a flame, fire, heat lamp, heater, or radiator. Depending on the temperature, burns may occur in seconds. Radiant heat can cause substantial injury to the outside of the animal’s body. In the early stages right after the injury, the hair is intact and the skin is erythemic and may be blistered (although not as common in animals) (Pope, 2003) with possible skin sloughing. After prolonged exposure the skin may develop a leathery consistency with eventual charring (DiMaio & DiMaio, 2001; Merck & Miller, 2013).