these drugs should be used judiciously and in regional routes (e.g. intra‐articular) whenever possible.
Similarly, excessive doses of long‐acting alpha‐2 agonists given over several hours (e.g. for standing sedation) should be avoided if possible (i.e. long procedures could be staged into two shorter procedures separated by a return to feeding).
Anticholinergics, as discussed previously, are recommended to be used with care and only when low heart rate is detrimental, reversal of agents causing bradycardia is not possible, and other methods used to improve hemodynamics have failed. They should be titrated carefully such that the lowest effective dose is used.
Use of local anesthetic techniques may be helpful from the standpoint of prevention of post‐operative pain (thus aiding a quicker return to normal feeding behavior) as well as to reduce the dose of sedative and systemic analgesic drugs required to complete the procedure.
There is also no conclusive recommendation as to the most appropriate pre‐operative fasting or post‐operative re‐feeding regimen to prevent post‐operative colic, though as mentioned earlier fasting does contribute to decreases in gastrointestinal motility.
Monitoring
In many hospitals, it is routine to monitor and record fecal output in addition to both subjective and physiological indicators of abdominal discomfort in the post‐anesthetic period. Early signs of discomfort may be subtle or masked by systemic use of analgesic drugs (e.g. phenylbutazone) in the peri‐operative period. Since the consequences of impaired gastrointestinal motility in the horse are potentially dire, observation of behavior and normal fecal production in the recovery period are essential.
Treatment
In‐depth discussion of the treatment of post‐anesthesia gastrointestinal dysfunction is beyond the scope of this chapter, and management strategies for post‐operative ileus have been reviewed elsewhere [147, 148].
Expected Outcome
Post‐anesthetic gastrointestinal dysfunction may respond well to medical management or, depending on the severity, could necessitate exploratory abdominal surgery or euthanasia.
Summary
Complications are associated with sedation and general anesthesia in all species. Some of these are further magnified in the horse as a result of their size, unique associated physiology, and temperament. However, anticipation and management of the same can go a long way toward alleviating significant untoward outcomes.
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