Lacerations and wounds to the lower leg of the horse are perhaps the most common equine injuries. Trauma is the most common
cause and includes fence injuries (board and wire), kicks, and other environmentally caused wounds. Because of the variable
blood supply to the lower leg of the horse and because of the lack of muscle, fat and extra skin tissue, these wounds can
be very difficult to deal with. Primary closure within the four-hour "golden period" allows for the best results, but these
wounds often occur at pasture, and they are not discovered until much later. Meticulous cleaning, scrubbing and flushing of
these wounds are required, and it is not unusual for the wound-preparation time to equal or exceed the time taken to suture
or staple the injury.
Post operatively, a well-fitted supportive leg wrap should be applied. The use of an absorptive non-stick pad next to the
sutured area can help with initial healing. Feminine pads and liners work very well in this capacity. Antibiotics may be given
via regional perfusion if contamination/infection is suspected.
Occasionally, sutured lower-leg wounds are under great tissue stress. Wounds across a flexion/extension surface, such as across
the front of the fetlock or down the back of the pastern, may be under tension as a horse moves. These repairs have little
chance of success as the constant motion weakens the suture line during time. Wounds of this nature may benefit from the placement
of a cast. Cast application can be done under general anesthesia or under sedation in the standing horse. Recovery from general
anesthesia for a horse wearing a cast is a difficult procedure, so cast placement under standing sedation is used whenever
possible. This is especially true if the wound itself was successfully repaired under sedation. There is often little practical
reason to subject the horse to the additional stress/risk of general anesthesia.
Cast management must be constant and vigilant because cast rubs and the resultant tissue trauma can be more devastating than
the initial wound. Monitor the cast for heat, irritation and observe the horse for a decrease in use of the leg or for any
signs of discomfort. Thermography, the use of a special ultra-sensitive camera to detect changes in heat in the body, has
proven to be especially good at monitoring casts. If the camera shows even a small increase in heat in some area of the cast,
then studies have shown that those areas will develop sores. Knowing this, the veterinary clinician can make a small partial
thickness cut in the cast over the effected spot to relieve the pressure. In this way casts can be maintained longer and healing
has a better chance of continuing without the starts and stops of multiple cast changes.
Lacerations and punctures to the lower leg in areas over joints or tendons are a combination of superficial injuries to the
skin and potentially serious damage to deeper structures. These injuries are also considered medical emergencies. Joints and
tendon sheaths should be evaluated for puncture by tapping into the suspected area from a location opposite to the site of
trauma. If a joint tap reveals bacteria or blood, then it is a logical assumption that the trauma has caused penetration into
the joint and that an infection is likely. Immediate and aggressive use of antibiotics is necessary along with copious joint
lavage or tendon sheath flushing.
Treating equine lower-leg injuries that may or may not involve joints, ligaments and other structures must be monitored closely.
"Be persistent," says Dr. Reed Hanson, surgeon at Auburn University's College of Veterinary Medicine. "Set up specific appointments
to return and recheck these wounds rather than relying on clients to evaluate the injuries and report to your office."
This hands-on, aggressive approach generates more practice income, and it is simply a better way to monitor the progress of
these potentially serious wounds.
"It is a win-win situation for you, the client and, most importantly, for the horse," Hanson says.
Consistent monitoring will allow the practitioner to adjust casts and/or leg wraps, trim damaged tissue as the wound heals,
or change and adjust antibiotic dosages. Close monitoring of wounds will improve healing significantly.
Editor's Note: In this second part of a three-part series, Dr. Kenneth L. Marcella discusses body wound care with leading practitioners.
Open DVM Newsmagazine's March issue for the first installment on head wounds, or visit our Web site at
http://www.dvmnews.com/. We will complete the series next month with rope burns, hoof/heal lacerations and a chance to see how your wound-care acumen
rates against the experts in a photo-intensive Wound Care Quiz.
Dr. Marcella, a 1983 graduate of Cornell University's veterinary college, was a professor of comparative medicine at the University
of Virginia. His interests include muscle problems in sport horses, rehabilitation and other performance issues.