The use of phenylephrine in the treatment of nephrosplenic entrapment of the large colon in horses

Nephrosplenic entrapment is a commonly diagnosed cause of acute colic that may be corrected using surgical or non-surgical methods and has a good prognosis for survival. Intravenous administration of phenylephrine at doses ranging from 20–60 μg/kg given over 5–15 min often followed by forced exercise, various rolling techniques under general anaesthesia, or a combination of therapies has been reported. Correction of the entrapment via exploratory celiotomy may be challenging in certain cases and is hampered by marked splenic enlargement. The case report by Loomes and Anderson (2019) in this issue described a novel method of reducing the size of the spleen by direct intra-splenic injection of phenylephrine, in a case non-responsive to intravenous phenylephrine administration, which facilitated surgical correction of the nephrosplenic entrapment.