['It has been shown that the selective 5-HT4 receptor agonist tegaserod induces an increase in frequency and amplitude of contractions in isolated muscle preparations of equine ileum and pelvic flexure.', 'To investigate the effects of tegaserod on gut motility and transit of spheres in normal horses.', 'Six mature Freiberger horses were kept under standardised conditions. Effects of tegaserod (0.02 mg/kg bwt i.v. b.i.d. for 2 days) or vehicle on intestinal transit of barium-filled spheres, defaecation and gut sounds were studied in a cross-over design. Spheres were given via stomach tube prior to the first dosing of tegaserod or vehicle. Faeces were collected every 3 h and spheres eliminated were identified radiologically in the faeces.', 'Tegaserod significantly accelerated the gastrointestinal (GI) transit time of spheres and increased the frequency of defaecation and scores of gut sounds compared to vehicle. The compound was well tolerated; no effects on behaviour, body temperature, heart rate, respiratory rate and clinical laboratory data were observed.'] Does tegaserod ( HTF 919 ) stimulate gut motility in normal horses?