Gastroenteritis.

This condition consists in an inflammation of the stomach and intestines. Instead of being confined to the mucous, or lining, membrane, as in gastrointestinal catarrh, the inflammatory process extends deeper and may even involve the entire thickness of the wall of the organ.

This disease may be caused by irritant feed, hot drinks, sudden chilling, moldy or decayed feeds, foul water, parasites, or by chemical poisons. It may also complicate some general diseases, especially infectious diseases, as anthrax, influenza, rabies, or petechial fever. Long-continued obstruction of the bowels or displacement resulting in death are preceded by enteritis.

Fonte: Diseases of the Horse