PURDUE    ,    jm\
veterinary medical ( ■
VOLUME 5, NUMBER 1
WINTER -SPRING 1979
COLIC SURGERY IN THE EQUINE
Colic, the manifestation of abdominal pain, is a common
syndrome in the horse. Fortunately most horses with
colic respond satisfactorily to medical therapy, or, to no
therapy at all. Occasionally surgical intervention is
necessary. At Purdue approximately 30 laparotomies
per year are being performed on horses with colic.
Conditions successfully corrected by surgery include
volvulus, torsion, intususception, strangulation, incarceration and infarction of the small or large intestine,
enteroliths, and impactions not responsive to medical
therapy.
The majority of horses on which colic surgery is performed are initially attended by practitioners who
subsequently refer the horses to Purdue. Upon arrival
at the clinic a standard examination of the patient is
performed. This examination includes passage of a
stomach tube, auscultation of the abdomen, rectal
exploration, assessment of the mucous membranes,
determination   of  the   pulse   rate  and  character,  and
and determination of blood electrolytes and lactic acid
levels are performed in selected cases. The examination
Halothane is administered to the horse with intermittant positive
pressure ventilation (IPPV) for maintenance of anesthesia. The
instruments nearest the anesthetist allow continuous monitoring of the electrocardiogram and the mean arterial biood pressure during anesthesia.
determination of the respiration rate and rectal temperature. Packed cell volume, total serum protein, and
blood gases are also assessed. An abdominal paracentesis
A grossly distended small intestine resulting from incarceration
through a mesenteric rent.
has three main purposes.   These are to make a definitive
diagnosis,   decide   whether   the  colic  can   be   handled
medically or surgically, and provide an accurate prognosis to the owner.   Although it is not always possible
to make a definitive diagnosis, the most important thing
to deteimine ib whether or not a surgical condition is ]
present.    The horse with a surgical condition will not
benefit from a delay  in  surgery.   These horses are in
some  degree of endotoxic shock, and  eventually this!
shock will become irreversible.    It is unlikely that the I
horse with  blue mucous membranes, a capillary refill
time of 5 seconds, a heart rate of 140 and packed cell
volume  of 67%  will  survive a general  anesthetic and
surgical  procedure even  though  it may be technically
feasible  to  correct  the   initiating abdominal  problem.
Colic surgery is a team effort at the Large Animal
Clinic. The team consists of a surgeon, 2 to 3 assistant
surgeons, a surgical nurse, an anesthetist and several
auxiliary personnel for performing laboratory procedures, maintaining fluid therapy and providing proper
instruments for surgery. Most of the colic surgeries are
performed at night as this seems to be the usual time for
the horses to arrive at the clinic. During the interval
needed for all personnel to arrive, the horse is prepared
for surgery. Fluid therapy and antibiotics are administered and the abdomen clipped. The goal is to keep
the surgical time and anesthetic period at two hours or
less. Prolonged anesthesia in the "shocky" and toxic
horse is contraindicated.
Following surgery the horse is placed in a padded recovery stall and oxygen is administered until the horse
is able to stand. The post-operative period is critical to
survival and the horse is not "out of the woods" just
because it has survived the surgical procedure. Continuous monitoring for 24 hours is the rule and is continued with complications. These include ileus, endotoxic
shock, peritonitis, and gastroenteritis. During the period
of intensive care clinical parameters are monitored as
well as the blood gases, blood electrolytes, packed cell
volume, and total serum protein. Senior students and
technicians are an invaluable asset in monitoring and
A ventral midline laparotomy is used for surgical exploration
of the horse with colic. The horse in this figure is being positioned and secured in dorsal recumbancy prior to surgery. The
air mattress is used to prevent postoperative myositis.
treating   the   horses   during  the   postoperative   period.
Early recognition and surgical intervention in the horse
with a surgical colic is critical to a successful outcome.
Factors suggesting surgical intervention include: reflux
of fluids during passage of a nasogastric tube; extreme
pain not responsive to analgesics; failure to respond to
medical therapy; progressive systemic deterioration;
extreme abdominal distension; turgid loops of intestine,
displaced intestine or tight painful bands noted on rectal
examination; and serosanquinous abdominal fluid.
At Purdue a large part of the surgical success is the result
of many early referrals by the initial examining veterinarian. The referring practitioner is a critical member of
the colic team. The current success rate is about 60%,
this being the percentage of horses operated on that
have returned to normal preoperative use. It is felt
that this percentage can be improved in the future by
a combination of increased awareness of the need for
early surgical intervention, refined surgical techniques,
and improved medical management in the postoperative
period. Dr. Stephen B. Adams
Above - RECOGNITION TO OUTSTANDING STUDENTS. Front row (I to r): Cheryl Clenott, Phil Beachy, Barb
Powers, Hedley Marks, Loren Weaver. Middle row: Leon Thorpe, Rick Hartigan, Kathleen Neuhoff, Janice Mcintosh, Jim Radcliffe, Dr. John Van Vleet. Back row: Dan Lochner, Scott Allenstein, Rob Holl, Mike Cook, Jim
Rivere.   A few were missing. Right - The profession and Purdue's School of Veterinary Medicine received some
very supportive exposure from TV Channel 6 (Indianapolis) in February on an approximately ten-minute documentary. Linda Lupear of that station was the producer and she did, in our opinion, a very fine job of highlighting
interesting and significant facets of the profession in a relative short time span. Pictured are students viewing the
program u j^^schonl's programmed instruction audio-visual facility