USE OF ULTRASOUND IN HORSES FOR DIAGNOSIS OF LEFT DORSAL DISPLACEMENTOF THE LARGE COLON AND MONITORING ITS NONSURGICAL CORRECTION

During a 28 month period, 82 horses with clinical signs of abdominal p ain were examined for left dorsal displacement of the large colon (LDD LC) using percutaneous ultrasound. Left dorsal displacement of the lar ge colon was diagnosed when a gas echo dorsal to the spleen obliterate d the dorsal splenic border, or when the colon was observed lateral to the spleen. In 42 horses, ultrasound confirmed a diagnosis of LDDLC a nd 40 horses had no evidence of LDDLC. There were five false negative results and no false positives. In four horses with LDDLC, the colon w as displaced between the spleen and body wall; three of these colic ep isodes resolved with medical therapy and the fourth required a celioto my to relieve a sand impaction. The remaining 38 horses had a renosple nic entrapment; surgical correction was elected in 4 horses, 21 horses were corrected by a nonsurgical rolling procedure, 12 were corrected at surgery after an unsuccessful rolling attempt, and one was correcte d by rolling but required surgery later because of an additional lesio n. Percutaneous abdominal ultrasound was a valuable aid in the diagnos is of LDDLC and in confirming correction of the displacement after a n onsurgical rolling procedure.