The approach to treating colic demands two separate avenues: first, control of the pain, and next, control or elimination of the cause.
The severity of pain in colic varies widely from unease or discomfort manifested by the horse as mild pacing, pawing, or gazing at its flanks to extreme and violent pain where the horse is virtually uncontrollable and throwing itself around the stall or rolling.
In general, the severity of the pain and the ease with which it is controlled give an indication as to the seriousness of the underlying problem. That is, mild pain that is quickly controlled with non-narcotic and nonsedative medications usually portends a favorable outcome if the cause is appropriately’ treated, while pain that can only be controlled (or is poorly controlled) with heavy sedation or narcotics usually indicates a more serious problem. However, horses vary in their tolerance of pain, which can be confusing. Also, a sudden decrease in severe pain, not associated with treatment, may be an ominous sign that indicates a portion of the intestinal tract has ruptured (the relief of pressure is what causes the pain to lessen).
Unless the horse is in severe distress, its pain is usually approached by use of a non-narcotic analgesic. Dipyrone is a traditional first-line choice and is believed to have both analgesic and antispasmodic properties (although the latter effect is somewhat in question). Banamine is another widely used analgesic for colic pain, as is Torbugesic. Generally speaking, however, phenylbutazone is not very effective in controlling abdominal pain.
Pain control may also be approached through the use of drugs with both analgesic and sedative properties. These would include xylazine (Rompun, Anased) and Dormosedan. The common tranquilizer acepromazine is also potentially very effective. It does not have analgesic properties but is effective at relieving intestinal-tract spasm.
Finally, pain control may be attempted by use of an antispasmodic drug, such as atropine, alone or in combination with an analgesic agent.
If non-narcotic measures are not effective in controlling pain, narcotics may be necessary.
It must be pointed out here that the use of any drug with sedative or tranquilizing properties can be dangerous in a colic case. Colic is often associated with extreme changes in fluid and electrolyte balances, and a state of shock. Sedative/tranquilizer drugs (and atropine) have potent effects on the heart and circulation that could dangerously worsen the horse’s condition and/or make its condition unsuitable for any necessary surgery.
Torbugesic, a non-narcotic analgesic, is actually a more potent pain reliever in colic cases than many of the narcotics. Torbugesic also has the ability to reverse the effects of some narcotics, making it safe to use even if narcotics have already been administered. For strength of action, Torbugesic could be considered the drug of choice in colic cases; however, its high expense often precludes its use.
TREATING THE CAUSE OF COLIC
As mentioned, there are many possible causes of colic. Colic is not controlled simply because the horse has been given a drug that controls its pain. The cause must be found and addressed.
Diagnosing colic is a job for the experienced veterinarian. Most of the necessary procedures are the most dangerous to perform. These include passing a stomach tube, doing a rectal examination, and inserting a needle into the horse’s belly to obtain a fluid sample. All of these procedures must be done to correctly diagnose the cause of the colic, vet each of them has the potential to actually kill the horse, either directly or as a result of some complication. Nevertheless, until the cause is determined, no effective treatment can be given.
Most horses with colic may be in pain but are generally speaking, relatively healthy Those requiring surgery however, are at risk of developing shock, and much of the examination will be directed toward detecting the early signs of this.
In most cases of colic the horse’s temperature remains normal (38,0C, I00.5F). Horses with advanced shock will have a decreased temperature and their lower limbs and ears will feel cold, but a high temperature is uncommon. Both pain and shock will cause the heart and respiratory rates to rise. If the heart rate is elevated from its normal range (36-44 beats per minute) due to pain, it seldom rises above 60 beats per minute. In advanced shock, however, it may reach as high as 150 beats per minute. In contrast the respiratory rate, which in a normal horse may be between 6 -16 breaths per minute, can be markedly elevated due to pain alone, as high as 60 breaths per minute, and may even be higher than the heart rate.
Your vet will spend some time listening to the horse’s gut sounds using stethoscope. The intestines make noise as the muscle in their wall contracts and moves food along. Horses normally have quite loud gut sounds. In colic these may be markedly increased and it may be possible to hear them from a distance. This is generally a good sign – if gut sounds are decreased this may mean that the gut has twisted and thus stop working and making any noise. Or it may simply mean that your horse is constipated.
Despite detailed examination it is often impossible to establish the exact cause of the colic. The horse should be treated with analgesics and regularly monitor the recovery and avoid any recurrence. Withdrawing all the food from horses with colic is advisable, until after the problem has resolved. Fortunately most cases resolve with medical treatment, even if the exact cause has not been diagnosed.
Various types of colic include impaction, diarrhea, ulcers and other stomach disorders, spasmodic colic, gas colic, sand colic and surgical colic. See individual colic for further treatment.