Dr. Colleen Lewis / January 5, 2017
Every full thickness skin injury is different, yet all share the need for attention. Immediate attention may be required to control bleeding, but there are other not-so-obvious reasons to begin wound treatment as soon as possible. As a rule of thumb: full thickness wounds require antibiotics to prevent infection. These medications are given either orally or as an injection. If a wound is causing pain or discomfort, pain medications are important as well. Injuries can keep a horse from eating or drinking sufficiently or cause rubbing and further injury. Pain medications can help to prevent rubbing and keep a healthy appetite in check to promote wound healing. Prompt repair of skin wounds, within 24 hours, will minimize pain and severity of scar tissue formation as well. Lacerations that are surgically repaired will usually require less long term wound care than untreated wounds. Even if it looks like some skin is missing, many surgical closure techniques can decrease and even eliminate large gaps and holes. The skin is very pliable and can often be stretched or released: a technique used to spread the skin over a larger area to cover deficits. After 24 hours, enough devitalization has occurred that closing a wound will prove unsuccessful and other options will have to be used.
A “closed” wound is sutured completely closed, skin to skin, with no gaps, holes or drains. Sutures, staples and tissue adhesives can be used depending on skin thickness and tension on the skin edges. Sutures are generally removed in 10 to 14 days and little more than monitoring is required during the healing phase. An “open” wound is not sutured or reduced at all. Wounds left open to heal are meant to heal by second intention. Second intention wounds may require daily cleaning and copious flushing. Areas with devitalized tissue may require debriding. Depending on location, a wound may require extensive bandaging as well. Open wounds typically heal in two to four weeks, but may take longer if extensive damage or infection are present.
A “partially open” wound will be reduced with some form of skin to skin contact, but holes or gaps remain. A drain or multiple drains may be placed in any type of open wound to assist in keeping the wound open and draining as it heals from the inside out. Parts of the open areas will then heal with second intention. The early pink and lumpy tissue that forms over wounds can be seen in the first 24 hours. This early scar tissue is called granulation tissue. Once the wound is completely covered with granulation tissue around the drain, the drain is pulled and the remaining tracts are monitored and treated as needed until healed. Full coverage with granulation tissue is also a good sign that antibiotic usage may no longer be needed.
On occasion, our clients do not notice a wound right away and may find that an injury is already “old” when first noticed. Old lacerations can still be treated as open or partially open with drains; the more tissue we can cover with a natural skin bandage, the faster wound healing can get underway. Any pockets or dead spaces that are created by the injury as the skin is pulled away from the underlying connective tissue can become contaminated. Pockets will pool fluid and create a cesspool of infection if they are not oriented to drain naturally. Exploring the wound for pockets or secondary abscesses is an important part of wound care. If a fluid pocket develops below a wound, bacteria can start to produce toxins. These toxins will be absorbed into the bloodstream and cause grave illness that can lead to death. Opening pockets to allow complete drainaghorse e and to prevent the build up of infectious fluids is paramount.
Keeping a first aid kit in the barn will help in an emergency. Apply gauze, pressure and ice to bleeding wounds. Bandaging and chlorhexidine ointments can help to keep a wound clean until your veterinarian arrives. Wait for a veterinary diagnosis and advice before applying wound sprays or oily ointments. Unfortunately, some heavy silver sprays are only meant for open wounds and cannot be washed out of wounds that would have otherwise been sutured closed.
About the Author
Dr. Colleen Lewis is a 1996 graduate of Kansas State University, College of Veterinary Medicine. Her career has taken her to many places as a practice owner, consultant, embryologist, and mentor. She enjoys mixed animal practice, teaching, traveling, farming and high school sports with her husband, Andrew and their three boys.
