Amos, a 5 year old neutered male pointer mix, presented for a four day history of straining to defecate.  He was passing small amounts of stool at a time.  A barium x-ray study showed normal transit times and no evidence of foreign bodies.  There was, however, an area of the colon where the lumen appeared attenuated.  Exploratory surgery was elected.
A mass was located in the distal colon.  The owners were advised intra-operatively about the mass and the likely grave prognosis associated with neoplasia of the bowel.  A resection and anastomosis was performed and the mass submitted for pathology.  Much to our surprise and relief, the mass was read out as a severe, diffuse, chronic-active submucosal to mesenteric colitis.  No cancer.  Amos recovered uneventfully and is doing well.