PAIN relief for horses is almost entirely based around either non-steroidal anti-inflammatory drugs (NSAIDs) or opioid medicines like pethidine or butorphanol. There is a potent opioid analgesic, fentanyl, which is preferable to some others as it has fewer side effects, such as slowing the bowel and causing colic.
Fentanyl has to be given by intravenous
