Effect of romifidine on gastrointestinal motility, assessed by transrectal ultrasonography.

A technique of transrectal ultrasonography was developed to investigate the effects of romifidine 80 and 120 microg/kg bwt on intestinal motility in the horse. Motility of the small intestine, caecum and left ventral colon were assessed following injection of romifidine and a saline control, using a blinded, cross-over study design in 6 horses. Measurements were taken at 15, 30, 60, 120, 180 and 240 min after drug administration. There was a slight nonsignificant decrease in motility in the control group over the 4 h study period. Both doses of romifidine produced a marked decrease in gastrointestinal motility and were associated with the presence of reduced (nonpropulsive) contractions. Transrectal ultrasonography proved suitable for monitoring changes in the type and frequency of intestinal motility in the horse.