Researchers from Denmark and Norway report that morphine within a joint appears to be a useful part of a multimodal pain management protocol for horses that have undergone arthroscopic surgery.

Morphine is widely employed in human medicine after arthroscopic procedures; however, there is a reluctance to use the drug in equine medicine because unwanted side effects such as excitation, sedation, and reduced gastrointestinal motility.

Thus, alternative routes of administration using reduced doses of the drug could potentially decrease the side effects but still help control pain.

According to the study authors, "The discovery of opioid receptors in the equine synovial membrane makes it plausible that (intra-articularly) administered morphine may have analgesic and anti-inflammatory properties in horses