Recent emergency cases at our veterinary hospital prompted today's subject matter. Veterinarians commonly field calls not just during business hours, but at night and on Sundays regarding emergencies that deal with wound and laceration care. Today I'll share a little of what we deal with to give you an appreciation for a veterinarian's thought process on the subject.
First, a definition: laceration. A laceration is basically a cut through tissue. Most of the time lacerations are obviously visible to pet owners, as bleeding is common from the skin, subcutaneous tissue and underlying muscle if it is involved. Lacerations are caused from trauma, with causes ranging from the tooth of another animal to a sharp edge of metal or glass to the bumper of a car. These wounds demand care for three primary reasons: 1) control of bleeding, 2) reapposition of tissue to a healing state and 3) prevention of infection.
Bleeding certainly is a valid concern, and most pet owners are keen to the fact that bleeding from an active pumping vessel or blood oozing from a wound past a four- to five-minute clotting time is a problem. First aid, followed by veterinary assistance, is necessary on these. But beyond these concerns, surgical reapposition of tissues (putting the edges of the wound back together) is necessary by the veterinarian. Any hemorrhaging needs to be stopped, cavities need to be closed (if the thorax or abdomen are involved) and, of course, the surgeon must close the muscle, subcutaneous tissue and skin as he works his way outward. Cases involving bone fractures demand special consideration, and deserve discussion in a separate column.
The "golden period" surgeons speak of also applies to veterinary medicine, and refers to the freshness of the tissues when the case is presented. If a wound is more than three to four hours old, we deem it outside the golden period of primary closure. Primary closure means the surgeon can clean and disinfect, then simply reappose the layers with sutures or staples. Secondary closure is when using alternate methods of wound management or by second intention, a wound is allowed to heal. In a nutshell, these wounds can still be treated as "surgical-closure lacerations" but their edges need freshening up and disinfection. In stale or already-infected circumstances, the process of debridement, or tissue resection to first prepare the wound, may be necessary before surgical closure is attempted.
The third element in laceration circumstances is prevention of infection. In the previous paragraph, note that I mentioned the already-infected ones, and these commonly are presented in cats and dogs who have been in fights and stayed "on the road" a few days after the injury. Not only must vets abide by the "outside the golden period" rules on these, but pre- and post-loading on antibiotics for the patient are a must. In severe wounds, veterinarians may also utilize drains to allow infectious fluids to flow away from the wound site.
In hard-to-close wounds or severely infected wounds, surgical closure may not be possible at all. A process called granulation, or third intention, is what we are left with. This is the same sutureless rationale used in puncture management (wounds under 1/2 inch that only penetrate skin and subcutis). As you can appreciate, there are some borderline calls where the matter is left up to your veterinarian's judgment.
Today's overview of wound and laceration management is simply a brief summary to give pet owners a view into their veterinarians' thought process.
Chris Duke is a veterinarian at Bienville Animal Medical Center in Ocean Springs, Miss.