Surgical intervention in the treatment of colics of the horse is of value only in certain displacements and impactions. The etiology of the colic must be considered before surgical relief is attempted. Uncomplicated spasmodic colic will usually subside within a few hours with or without treatment. Colics caused by aneurysms of the anterior mesenteric artery or its major branches are very commonly observed and offer a poor prognosis regardless of the type of treatment employed.