Colic surgery - Early referral increases survival chances
Ken Marcella, D.V.M.
Should surgery be done? Will my horse survive the procedure? Can I afford it? Will he ever be the same? These questions are much better asked when there is no crisis and when you can clearly think about them.
Colic is a general term for any type of intestinal discomfort. This can vary from a bacterial or viral infection - enteritis - to an obstruction or blockage from a stone (enterolith) or build-up of hard fecal material. Any number of twists, rotations or distentions of normal intestine can also lead to colic.
Not eating usually gets the colicky horse noticed. He may be sweaty and paw or look at its flanks. Occasionally a colicky horse will lie down and get up repeatedly or may try to roll when down. The affected horse will have an elevated heart rate, and its gum color can vary from pale pink to bright red to light blue/purple depending on the cause of the colic. Gut sounds can be variable, as well. An increase in sounds usually indicates a gas build-up; an absence of sounds indicates a stoppage of normal digestion.
A good physical exam should be done, checking gum color, heart rate, and the gut sounds. Your vet should be called and this information relayed. Many times the veterinarian will prescribe a pain reliever and intestinal muscle relaxant, such as Banamine. Most colic cases respond to this type of conservative treatment, and no further care is required.
If the horse does not get better or if the colic signs worsen, a veterinarian should examine the horse. After a physical exam and the administration of more powerful pain relievers, the veterinarian will usually pass a tube into the horse's nostril, down the throat to the stomach. Because horses cannot empty their stomachs by vomiting, a build-up of gas and fluid in the stomach from colic can be painful. Passing the stomach tube allows the vet to remove this fluid and gas to relieve the pain. A rectal exam checks for blockages, twists or abnormal placement of the intestines. If a problem is palpated, the vet can give the owner a good idea of the possible treatment options and their outcomes.
Many cases of colic will be resolved following nasogastric tube decompression, but colic treatment is a matter of closely watching a number of body parameters and looking for progression. Are the gut sounds getting more normal and generalized? Is the heart rate going up or down? Does the gum color more closely resemble a light pink? Most horses slowly begin to move toward normal, and these colics resolve.
The few cases that do not show improvement at this point should be taken seriously, and your veterinarian will usually refer these to the closest surgical facility. Because colic surgery survival is related to the speed at which the horse is taken to the operating room, quick assessment of the case is essential and early referral by field veterinarians can lead to an increase in survival. The referral does not necessarily mean surgery, but these cases do require intravenous fluids and need to be close to help should the condition worsen.
Once you arrive at the surgical hospital, your horse will be re-examined and rectal exams conducted. Blood will be drawn to check for hydration and infection and to evaluate the health of the intestines. If an infection or a blockage with gut damage has occurred, then certain blood parameters will be altered. A needle will be placed into the belly of the horse and peritoneal fluid will be sampled. It should be a low-protein, straw-colored, clear fluid. Blood, thickness or fecal material contamination means that the intestines are damaged and that the gut contents are leaking into the belly. In order to correct the dehydration that is occurring because so much internal fluid is going to the irritated bowel, a large catheter will be put in your horse's vein, and fluids will be started. Again, many colics resolve with fluid therapy, and only a small number continue to be painful and to need surgery.
Once your horse's abdomen is clipped and prepared and its legs wrapped, it will be taken to an anesthesia induction room. There the vet will administer injectable anesthetics and your horse will lie down. These rooms are usually small and heavily padded to prevent injury during induction or recovery, which also takes place here.
After induction, your horse will have a breathing tube inserted into its windpipe, and it will be placed on inhalant anesthesia. Monitors for heart rate and blood pressure will be attached, and it will be hoisted onto a surgical table. The surgeon then uses a scalpel to open the abdomen and an examination is made. If a piece of intestine has become gas distended and moved to the wrong place, the gas is removed with a needle and the intestine is replaced where it belongs. If there is a flip or a twist to the intestine, the surgeon straightens and replaces.
If the intestine has been damaged, it may have to be resected. In this procedure, the surgeon clamps both ends of the intestine to isolate the damaged section. Care must be taken to preserve good blood vessel supply to the edges. The damaged section is removed and the two ends are re-attached. There are many areas of equine intestine where this can be done easily; there are other sections where it cannot. If the damage is in these, or if the damage is extensive, then the horse may not be able to be helped, even with surgery.
Some colic cases require that the surgeon open the intestine and flush out or remove hard packed fecal material or intestinal stones. Special pads, towels and trays are used and the intestine is opened, cleaned out and sutured closed.
After the surgeon has identified and corrected whatever problem caused the colic, the abdomen is flushed with sterile fluid and closed. A correctly closed belly wall heals quickly and allows the horse to return to full use, often within a period of six to 10 weeks. Improper closure results in hernias and a weak belly wall.
After the surgery, the horse is slowly removed from the inhalant anesthesia and starts to breathe normally.
As with any post-surgical patient, time is required for the horse to completely recover, but within 12 to 24 hours it should be alert and active.
The post surgical horse will be fed slowly at first and on a schedule determined by the nature of its colic and the particulars of the repair. Most uncomplicated colic surgeries return home within a few days and are rested in the stall for two to three weeks.
Ken Marcella, D.V.M., is based at the Chattahoochee Equine Center in Canton, Ga.