Comparison of three premedication techniques on passage of an endoscope through the pyloric sphincter in dogs

Abstract

μ agonist opioids may increase pyloric sphincter tone in dogs, making duodenal passage of an endoscope difficult. Butorphanol, a κ agonist/μ antagonist opioid, was examined to determine its effects on ease of passing an endoscope through the pyloric sphincter in dogs. Butorphanol (B; n = 10), butorphanol-atropine (BA; n = 10), butorphanol-atropine-acepromazine (BAAce; n = 10) and saline control (S; n = 10) were examined for use as premedications in dogs undergoing gastroduodenoscopy (GD).