Chronic colic in the mature horse: a retrospective review of 106 cases.

The clinical features of 106 horses presenting with chronic colic examined over a 5 year period were reviewed. Chronic colic was defined as colic signs observed daily for 3 days or longer, except when masked by analgesics. The diagnosed causes of chronic colic included colonic impaction (31%), peritonitis (16%), enteritis/colitis (7%), colonic displacement/torsion (6%) and lymphosarcoma (4%). A variety of other diseases were diagnosed in a small number of cases, including intestinal adhesions, ileal obstructions, grass sickness, liver disease, caecal impactions, thromboembolic disease, intussusceptions etc. No diagnosis was reached in 8% of cases. Diagnosis was relatively easily achieved in most cases of colonic impaction and peritonitis by results of transrectal palpation and evaluation of peritoneal fluid. Specific clinical features, transrectal palpation, abdominal paracentesis and laboratory evaluations of blood were helpful in the diagnosis of some of the other diseases, but exploratory laparotomy remained necessary in a few cases to achieve a diagnosis.